diff --git a/Cargo.lock b/Cargo.lock
index 731ca28a41..0c7a060ff5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2769,7 +2769,6 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "cid",
- "fil_actor_eam",
  "fil_actors_evm_shared",
  "fil_actors_runtime",
  "frc42_dispatch",
@@ -2782,6 +2781,7 @@ dependencies = [
  "num-derive 0.3.3",
  "num-traits",
  "serde",
+ "serde_tuple",
 ]
 
 [[package]]
diff --git a/contracts/binding/Cargo.toml b/contracts/binding/Cargo.toml
index fc82cff9bb..e3a27d90de 100644
--- a/contracts/binding/Cargo.toml
+++ b/contracts/binding/Cargo.toml
@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 ethers = { workspace = true, features = ["abigen", "ws"] }
-fvm_shared = { workspace = true, features = ["crypto"] }
+fvm_shared = { workspace = true }
 anyhow = { workspace = true }
 
 [build-dependencies]
diff --git a/contracts/contracts/activities/Activity.sol b/contracts/contracts/activities/Activity.sol
index 56700d7493..cdb6982dcd 100644
--- a/contracts/contracts/activities/Activity.sol
+++ b/contracts/contracts/activities/Activity.sol
@@ -3,55 +3,63 @@ pragma solidity ^0.8.23;
 
 import {SubnetID} from "../structs/Subnet.sol";
 
-event ActivityReportCreated(uint64 checkpointHeight, ActivityReport report);
+// Event to be emitted within the subnet when a new activity summary has been recorded.
+event ActivityRollupRecorded(uint64 checkpointHeight, FullActivityRollup rollup);
 
-/// The full validator activities report
-struct ActivityReport {
-    ValidatorActivityReport[] validators;
+// Carries a set of reports summarising various aspects of the activity that took place in the subnet between the
+// previous checkpoint and the checkpoint this summary is committed into. If this is the first checkpoint, the summary
+// contains information about the subnet's activity since genesis.
+// In the future we'll be having more kinds of activity reports here.
+struct FullActivityRollup {
+    /// A report of consensus-level activity that took place in the subnet between the previous checkpoint
+    /// and the checkpoint this summary is committed into.
+    /// @dev If there is a configuration change applied at this checkpoint, this carries information
+    /// about the _old_ validator set.
+    Consensus.FullSummary consensus;
 }
 
-struct ValidatorActivityReport {
-    /// @dev The validator whose activity we're reporting about.
-    address validator;
-    /// @dev The number of blocks committed by each validator in the position they appear in the validators array.
-    /// If there is a configuration change applied at this checkpoint, this carries information about the _old_ validator set.
-    uint64 blocksCommitted;
-    /// @dev Other metadata
-    bytes metadata;
+// Compressed representation of the activity summary that can be embedded in checkpoints to propagate up the hierarchy.
+struct CompressedActivityRollup {
+    Consensus.CompressedSummary consensus;
 }
 
-/// The summary for the child subnet activities that should be submitted to the parent subnet
-/// together with a bottom up checkpoint
-struct ActivitySummary {
-    /// The total number of distintive validators that have mined
-    uint64 totalActiveValidators;
-    /// The activity commitment for validators
-    bytes32 commitment;
+/// Namespace for consensus-level activity summaries.
+library Consensus {
+    type MerkleHash is bytes32;
 
-    // TODO: add relayed rewarder commitment
-}
+    // Aggregated stats for consensus-level activity.
+    struct AggregatedStats {
+        /// The total number of unique validators that have mined within this period.
+        uint64 totalActiveValidators;
+        /// The total number of blocks committed by all validators during this period.
+        uint64 totalNumBlocksCommitted;
+    }
 
-/// The summary for a single validator
-struct ValidatorSummary {
-    /// @dev The child subnet checkpoint height associated with this summary
-    uint64 checkpointHeight;
-    /// @dev The validator whose activity we're reporting about.
-    address validator;
-    /// @dev The number of blocks committed by each validator in the position they appear in the validators array.
-    /// If there is a configuration change applied at this checkpoint, this carries information about the _old_ validator set.
-    uint64 blocksCommitted;
-    /// @dev Other metadata
-    bytes metadata;
-}
+    // The full activity summary for consensus-level activity.
+    struct FullSummary {
+        AggregatedStats stats;
+        /// The breakdown of activity per validator.
+        ValidatorData[] data;
+    }
 
-/// The proof required for validators to claim rewards
-struct ValidatorClaimProof {
-    ValidatorSummary summary;
-    bytes32[] proof;
-}
+    // The compresed representation of the activity summary for consensus-level activity suitable for embedding in a checkpoint.
+    struct CompressedSummary {
+        AggregatedStats stats;
+        /// The commitment for the validator details, so that we don't have to transmit them in full.
+        MerkleHash dataRootCommitment;
+    }
+
+    struct ValidatorData {
+        /// @dev The validator whose activity we're reporting about, identified by the Ethereum address corresponding
+        /// to its secp256k1 pubkey.
+        address validator;
+        /// @dev The number of blocks committed by this validator during the summarised period.
+        uint64 blocksCommitted;
+    }
 
-/// The proofs to batch claim validator rewards in a specific subnet
-struct BatchClaimProofs {
-    SubnetID subnetId;
-    ValidatorClaimProof[] proofs;
+    /// The payload for validators to claim rewards
+    struct ValidatorClaim {
+        ValidatorData data;
+        MerkleHash[] proof;
+    }
 }
diff --git a/contracts/contracts/activities/IValidatorRewarder.sol b/contracts/contracts/activities/IValidatorRewarder.sol
index eb47b7fedb..052b233dea 100644
--- a/contracts/contracts/activities/IValidatorRewarder.sol
+++ b/contracts/contracts/activities/IValidatorRewarder.sol
@@ -2,7 +2,7 @@
 pragma solidity ^0.8.23;
 
 import {SubnetID} from "../structs/Subnet.sol";
-import {ValidatorSummary} from "./Activity.sol";
+import {Consensus} from "./Activity.sol";
 
 /// @title ValidatorRewarder interface.
 ///
@@ -14,7 +14,7 @@ interface IValidatorRewarder {
     /// @notice Called by the subnet manager contract to instruct the rewarder to process the subnet summary and
     /// disburse any relevant rewards.
     /// @dev This method should revert if the summary is invalid; this will cause the
-    function disburseRewards(SubnetID calldata id, ValidatorSummary calldata summary) external;
+    function disburseRewards(SubnetID calldata id, Consensus.ValidatorData calldata detail) external;
 }
 
 /// @title Validator reward setup interface
diff --git a/contracts/contracts/activities/LibActivityMerkleVerifier.sol b/contracts/contracts/activities/LibActivityMerkleVerifier.sol
index 433f57185e..579e64d5f0 100644
--- a/contracts/contracts/activities/LibActivityMerkleVerifier.sol
+++ b/contracts/contracts/activities/LibActivityMerkleVerifier.sol
@@ -3,25 +3,24 @@ pragma solidity ^0.8.23;
 
 import {SubnetID} from "../structs/Subnet.sol";
 import {InvalidProof} from "../errors/IPCErrors.sol";
-import {ValidatorSummary} from "./Activity.sol";
+import {Consensus} from "./Activity.sol";
 import {MerkleProof} from "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
 
 /// Verifies the proof to the commitment in subnet activity summary
 library LibActivityMerkleVerifier {
     function ensureValidProof(
         bytes32 commitment,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        Consensus.ValidatorData calldata detail,
+        Consensus.MerkleHash[] calldata proof
     ) internal pure {
         // Constructing leaf: https://github.com/OpenZeppelin/merkle-tree#leaf-hash
-        bytes32 leaf = keccak256(
-            bytes.concat(
-                keccak256(
-                    abi.encode(summary.validator, summary.blocksCommitted, summary.metadata)
-                )
-            )
-        );
-        bool valid = MerkleProof.verify({proof: proof, root: commitment, leaf: leaf});
+        bytes32 leaf = keccak256(bytes.concat(keccak256(abi.encode(detail.validator, detail.blocksCommitted))));
+        // converting proof to bytes32[]
+        bytes32[] memory proofBytes = new bytes32[](proof.length);
+        for (uint256 i = 0; i < proof.length; i++) {
+            proofBytes[i] = Consensus.MerkleHash.unwrap(proof[i]);
+        }
+        bool valid = MerkleProof.verify({proof: proofBytes, root: commitment, leaf: leaf});
         if (!valid) {
             revert InvalidProof();
         }
diff --git a/contracts/contracts/activities/ValidatorRewardFacet.sol b/contracts/contracts/activities/ValidatorRewardFacet.sol
index b18e8b5516..903ac87409 100644
--- a/contracts/contracts/activities/ValidatorRewardFacet.sol
+++ b/contracts/contracts/activities/ValidatorRewardFacet.sol
@@ -1,27 +1,32 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 pragma solidity ^0.8.23;
 
-import {EnumerableSet} from "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
-import {EnumerableMap} from "@openzeppelin/contracts/utils/structs/EnumerableMap.sol";
+import {Consensus} from "./Activity.sol";
 
+import {EnumerableMap} from "@openzeppelin/contracts/utils/structs/EnumerableMap.sol";
+import {EnumerableSet} from "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
+import {IValidatorRewarder, IValidatorRewardSetup} from "./IValidatorRewarder.sol";
+import {LibActivityMerkleVerifier} from "./LibActivityMerkleVerifier.sol";
+import {LibDiamond} from "../lib/LibDiamond.sol";
+import {NotValidator, SubnetNoTargetCommitment, CommitmentAlreadyInitialized, ValidatorAlreadyClaimed, NotGateway, NotOwner} from "../errors/IPCErrors.sol";
 import {Pausable} from "../lib/LibPausable.sol";
 import {ReentrancyGuard} from "../lib/LibReentrancyGuard.sol";
-import {NotValidator, SubnetNoTargetCommitment, CommitmentAlreadyInitialized, ValidatorAlreadyClaimed, NotGateway, NotOwner} from "../errors/IPCErrors.sol";
-import {ValidatorSummary, BatchClaimProofs} from "./Activity.sol";
-import {IValidatorRewarder, IValidatorRewardSetup} from "./IValidatorRewarder.sol";
 import {SubnetIDHelper} from "../lib/SubnetIDHelper.sol";
 import {SubnetID} from "../structs/Subnet.sol";
-import {LibActivityMerkleVerifier} from "./LibActivityMerkleVerifier.sol";
-import {LibDiamond} from "../lib/LibDiamond.sol";
 
 /// The validator reward facet for the parent subnet, i.e. for validators in the child subnet
 /// to claim their reward in the parent subnet, which should be the current subnet this facet
 /// is deployed.
 contract ValidatorRewardFacet is ReentrancyGuard, Pausable {
-    function batchClaim(BatchClaimProofs[] calldata payload) external nonReentrant whenNotPaused {
-        uint256 len = payload.length;
+    function batchSubnetClaim(
+        SubnetID calldata subnet,
+        uint64[] calldata checkpointHeights,
+        Consensus.ValidatorClaim[] calldata claims
+    ) external nonReentrant whenNotPaused {
+        require(checkpointHeights.length == claims.length, "length mismatch");
+        uint256 len = claims.length;
         for (uint256 i = 0; i < len; ) {
-            _batchClaimInSubnet(payload[i]);
+            _claim(subnet, checkpointHeights[i], claims[i].data, claims[i].proof);
             unchecked {
                 i++;
             }
@@ -30,43 +35,33 @@ contract ValidatorRewardFacet is ReentrancyGuard, Pausable {
 
     /// Validators claim their reward for doing work in the child subnet
     function claim(
-        SubnetID calldata subnetId,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        SubnetID calldata subnet,
+        uint64 checkpointHeight,
+        Consensus.ValidatorData calldata data,
+        Consensus.MerkleHash[] calldata proof
     ) external nonReentrant whenNotPaused {
-        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
-        _claim(s, subnetId, summary, proof);
+        _claim(subnet, checkpointHeight, data, proof);
     }
 
     // ======== Internal functions ===========
 
     function handleRelay() internal pure {
-        // no opt for now
+        // no-op for now
         return;
     }
 
-    function _batchClaimInSubnet(BatchClaimProofs calldata payload) internal {
-        uint256 len = payload.proofs.length;
-        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
-
-        for (uint256 i = 0; i < len; ) {
-            _claim(s, payload.subnetId, payload.proofs[i].summary, payload.proofs[i].proof);
-            unchecked {
-                i++;
-            }
-        }
-    }
-
     function _claim(
-        ValidatorRewardStorage storage s, 
         SubnetID calldata subnetId,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        uint64 checkpointHeight,
+        Consensus.ValidatorData calldata detail,
+        Consensus.MerkleHash[] calldata proof
     ) internal {
+        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
+
         // note: No need to check if the subnet is active. If the subnet is not active, the checkpointHeight
         // note: will never exist.
 
-        if (msg.sender != summary.validator) {
+        if (msg.sender != detail.validator) {
             revert NotValidator(msg.sender);
         }
 
@@ -74,7 +69,7 @@ contract ValidatorRewardFacet is ReentrancyGuard, Pausable {
             return handleRelay();
         }
 
-        LibValidatorReward.handleDistribution(s, subnetId, summary, proof);
+        LibValidatorReward.handleDistribution(subnetId, checkpointHeight, detail, proof);
     }
 }
 
@@ -102,7 +97,7 @@ struct ValidatorRewardStorage {
 }
 
 /// The payload for list commitments query
-struct ListCommimentDetail {
+struct ListCommitmentDetail {
     /// The child subnet checkpoint height
     uint64 checkpointHeight;
     /// The actual commiment of the activities
@@ -121,7 +116,7 @@ library LibValidatorReward {
     function initNewDistribution(
         SubnetID calldata subnetId,
         uint64 checkpointHeight,
-        bytes32 commitment,
+        Consensus.MerkleHash commitment,
         uint64 totalActiveValidators
     ) internal {
         ValidatorRewardStorage storage ds = facetStorage();
@@ -132,24 +127,24 @@ library LibValidatorReward {
             revert CommitmentAlreadyInitialized();
         }
 
-        ds.commitments[subnetKey].set(bytes32(uint256(checkpointHeight)), commitment);
+        ds.commitments[subnetKey].set(bytes32(uint256(checkpointHeight)), Consensus.MerkleHash.unwrap(commitment));
         ds.distributions[subnetKey][checkpointHeight].totalValidators = totalActiveValidators;
     }
 
     function listCommitments(
         SubnetID calldata subnetId
-    ) internal view returns (ListCommimentDetail[] memory listDetails) {
+    ) internal view returns (ListCommitmentDetail[] memory listDetails) {
         ValidatorRewardStorage storage ds = facetStorage();
 
         bytes32 subnetKey = subnetId.toHash();
 
         uint256 size = ds.commitments[subnetKey].length();
-        listDetails = new ListCommimentDetail[](size);
+        listDetails = new ListCommitmentDetail[](size);
 
         for (uint256 i = 0; i < size; ) {
             (bytes32 heightBytes32, bytes32 commitment) = ds.commitments[subnetKey].at(i);
 
-            listDetails[i] = ListCommimentDetail({
+            listDetails[i] = ListCommitmentDetail({
                 checkpointHeight: uint64(uint256(heightBytes32)),
                 commitment: commitment
             });
@@ -178,18 +173,20 @@ library LibValidatorReward {
     }
 
     function handleDistribution(
-        ValidatorRewardStorage storage s,
         SubnetID calldata subnetId,
-        ValidatorSummary calldata summary,
-        bytes32[] calldata proof
+        uint64 checkpointHeight,
+        Consensus.ValidatorData calldata detail,
+        Consensus.MerkleHash[] calldata proof
     ) internal {
+        ValidatorRewardStorage storage s = LibValidatorReward.facetStorage();
+
         bytes32 subnetKey = subnetId.toHash();
 
-        bytes32 commitment = ensureValidCommitment(s, subnetKey, summary.checkpointHeight);
-        LibActivityMerkleVerifier.ensureValidProof(commitment, summary, proof);
+        bytes32 commitment = ensureValidCommitment(s, subnetKey, checkpointHeight);
+        LibActivityMerkleVerifier.ensureValidProof(commitment, detail, proof);
 
-        validatorTryClaim(s, subnetKey, summary.checkpointHeight, summary.validator);
-        IValidatorRewarder(s.validatorRewarder).disburseRewards(subnetId, summary);
+        validatorTryClaim(s, subnetKey, checkpointHeight, detail.validator);
+        IValidatorRewarder(s.validatorRewarder).disburseRewards(subnetId, detail);
     }
 
     function ensureValidCommitment(
diff --git a/contracts/contracts/examples/ValidatorRewarderMap.sol b/contracts/contracts/examples/ValidatorRewarderMap.sol
index 1dfa33df5a..8f0ffd7d8d 100644
--- a/contracts/contracts/examples/ValidatorRewarderMap.sol
+++ b/contracts/contracts/examples/ValidatorRewarderMap.sol
@@ -2,34 +2,30 @@
 pragma solidity ^0.8.23;
 
 import {IValidatorRewarder} from "../activities/IValidatorRewarder.sol";
-import {ValidatorSummary} from "../activities/Activity.sol";
+import {Consensus} from "../activities/Activity.sol";
 import {SubnetID} from "../structs/Subnet.sol";
+import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
 
-/// An example validator rewarder implementation that tracks the accumulated
-/// reward for each valdiator only.
-contract ValidatorRewarderMap is IValidatorRewarder {
+/// An example validator rewarder implementation that only tracks the cumulative number of
+/// blocks committed by each validator.
+contract ValidatorRewarderMap is IValidatorRewarder, Ownable {
     SubnetID public subnetId;
-    address public owner;
 
     mapping(address => uint64) public blocksCommitted;
 
-    constructor() {
-        owner = msg.sender;
-    }
+    constructor() Ownable(msg.sender) {}
 
-    function setSubnet(SubnetID calldata id) external {
-        require(msg.sender == owner, "not owner");
+    function setSubnet(SubnetID calldata id) external onlyOwner {
         require(id.route.length > 0, "root not allowed");
-
         subnetId = id;
     }
 
-    function disburseRewards(SubnetID calldata id, ValidatorSummary calldata summary) external {
+    function disburseRewards(SubnetID calldata id, Consensus.ValidatorData calldata detail) external {
         require(keccak256(abi.encode(id)) == keccak256(abi.encode(subnetId)), "not my subnet");
 
         address actor = id.route[id.route.length - 1];
         require(actor == msg.sender, "not from subnet");
 
-        blocksCommitted[summary.validator] += summary.blocksCommitted;
+        blocksCommitted[detail.validator] += detail.blocksCommitted;
     }
 }
diff --git a/contracts/contracts/gateway/router/CheckpointingFacet.sol b/contracts/contracts/gateway/router/CheckpointingFacet.sol
index a88cf10266..fafbecc0ca 100644
--- a/contracts/contracts/gateway/router/CheckpointingFacet.sol
+++ b/contracts/contracts/gateway/router/CheckpointingFacet.sol
@@ -17,7 +17,7 @@ import {CrossMsgHelper} from "../../lib/CrossMsgHelper.sol";
 import {IpcEnvelope, SubnetID} from "../../structs/CrossNet.sol";
 import {SubnetIDHelper} from "../../lib/SubnetIDHelper.sol";
 
-import {ActivityReportCreated, ActivityReport} from "../../activities/Activity.sol";
+import {ActivityRollupRecorded, FullActivityRollup} from "../../activities/Activity.sol";
 
 contract CheckpointingFacet is GatewayActorModifiers {
     using SubnetIDHelper for SubnetID;
@@ -49,12 +49,12 @@ contract CheckpointingFacet is GatewayActorModifiers {
     /// @param checkpoint - a bottom-up checkpoint
     /// @param membershipRootHash - a root hash of the Merkle tree built from the validator public keys and their weight
     /// @param membershipWeight - the total weight of the membership
-    /// @param activityReport - the validator validator report
+    /// @param fullSummary - the full validators' activities summary
     function createBUChptWithActivities(
         BottomUpCheckpoint calldata checkpoint,
         bytes32 membershipRootHash,
         uint256 membershipWeight,
-        ActivityReport calldata activityReport
+        FullActivityRollup calldata fullSummary
     ) external systemActorOnly {
         if (LibGateway.bottomUpCheckpointExists(checkpoint.blockHeight)) {
             revert CheckpointAlreadyExists();
@@ -71,7 +71,7 @@ contract CheckpointingFacet is GatewayActorModifiers {
 
         LibGateway.storeBottomUpCheckpoint(checkpoint);
 
-        emit ActivityReportCreated(uint64(checkpoint.blockHeight), activityReport);
+        emit ActivityRollupRecorded(uint64(checkpoint.blockHeight), fullSummary);
     }
 
     /// @notice creates a new bottom-up checkpoint
diff --git a/contracts/contracts/lib/LibSubnetRegistryStorage.sol b/contracts/contracts/lib/LibSubnetRegistryStorage.sol
index 3983c76eea..c403815137 100644
--- a/contracts/contracts/lib/LibSubnetRegistryStorage.sol
+++ b/contracts/contracts/lib/LibSubnetRegistryStorage.sol
@@ -11,8 +11,8 @@ struct SubnetRegistryActorStorage {
     address SUBNET_ACTOR_GETTER_FACET;
     // solhint-disable-next-line var-name-mixedcase
     address SUBNET_ACTOR_MANAGER_FACET;
-    // solhint-disable-next-line var-name-mixedcase
     /// TODO: this should be removed as it's for collateral withdraw only, not rewarder
+    // solhint-disable-next-line var-name-mixedcase
     address SUBNET_ACTOR_REWARD_FACET;
     // solhint-disable-next-line var-name-mixedcase
     address SUBNET_ACTOR_CHECKPOINTING_FACET;
diff --git a/contracts/contracts/structs/CrossNet.sol b/contracts/contracts/structs/CrossNet.sol
index 1dc78be10d..9d00cda8db 100644
--- a/contracts/contracts/structs/CrossNet.sol
+++ b/contracts/contracts/structs/CrossNet.sol
@@ -3,7 +3,7 @@ pragma solidity ^0.8.23;
 
 import {SubnetID, IPCAddress} from "./Subnet.sol";
 import {EnumerableSet} from "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
-import {ActivitySummary} from "../activities/Activity.sol";
+import {CompressedActivityRollup} from "../activities/Activity.sol";
 
 uint64 constant MAX_MSGS_PER_BATCH = 10;
 uint256 constant BATCH_PERIOD = 100;
@@ -31,7 +31,7 @@ struct BottomUpCheckpoint {
     /// @dev Batch of messages to execute.
     IpcEnvelope[] msgs;
     /// @dev The activity summary from child subnet to parent subnet
-    ActivitySummary activities;
+    CompressedActivityRollup activities;
 }
 
 struct RelayedSummary {
diff --git a/contracts/contracts/subnet/SubnetActorCheckpointingFacet.sol b/contracts/contracts/subnet/SubnetActorCheckpointingFacet.sol
index c130b2ad5d..ad540d61f5 100644
--- a/contracts/contracts/subnet/SubnetActorCheckpointingFacet.sol
+++ b/contracts/contracts/subnet/SubnetActorCheckpointingFacet.sol
@@ -53,8 +53,8 @@ contract SubnetActorCheckpointingFacet is SubnetActorModifiers, ReentrancyGuard,
         LibValidatorReward.initNewDistribution(
             checkpoint.subnetID,
             uint64(checkpoint.blockHeight),
-            checkpoint.activities.commitment,
-            checkpoint.activities.totalActiveValidators
+            checkpoint.activities.consensus.dataRootCommitment,
+            checkpoint.activities.consensus.stats.totalActiveValidators
         );
 
         // confirming the changes in membership in the child
diff --git a/contracts/foundry.toml b/contracts/foundry.toml
index 2d7761d10c..eb7626a0e0 100644
--- a/contracts/foundry.toml
+++ b/contracts/foundry.toml
@@ -16,6 +16,7 @@ remappings = [
     "murky/=lib/murky/src/",
 ]
 allow_paths = ["../node_modules"]
+solc = "0.8.23"
 
 [fuzz]
 runs = 512
diff --git a/contracts/tasks/deploy-registry.ts b/contracts/tasks/deploy-registry.ts
index 51d4ac0ae1..50c0491e4e 100644
--- a/contracts/tasks/deploy-registry.ts
+++ b/contracts/tasks/deploy-registry.ts
@@ -37,17 +37,17 @@ task('deploy-registry')
             },
             { name: 'SubnetActorPauseFacet' },
             { name: 'SubnetActorRewardFacet' },
-            { 
+            {
                 name: 'SubnetActorCheckpointingFacet',
                 libraries: ['SubnetIDHelper'],
             },
             { name: 'DiamondCutFacet' },
             { name: 'DiamondLoupeFacet' },
             { name: 'OwnershipFacet' },
-            { 
+            {
                 name: 'ValidatorRewardFacet',
                 libraries: ['SubnetIDHelper'],
-             },
+            },
         )
 
         const registryFacets = await Deployments.deploy(
diff --git a/contracts/tasks/validator-rewarder.ts b/contracts/tasks/validator-rewarder.ts
index 0f7d784e82..095ffa9351 100644
--- a/contracts/tasks/validator-rewarder.ts
+++ b/contracts/tasks/validator-rewarder.ts
@@ -44,4 +44,4 @@ task('validator-rewarder-set-subnet')
         const contracts = await Deployments.resolve(hre, 'ValidatorRewarderMap')
         const contract = contracts.contracts.ValidatorRewarderMap
         await contract.setSubnet(subnetId)
-    })
\ No newline at end of file
+    })
diff --git a/contracts/test/IntegrationTestBase.sol b/contracts/test/IntegrationTestBase.sol
index 53d17edbfe..066c2e72e3 100644
--- a/contracts/test/IntegrationTestBase.sol
+++ b/contracts/test/IntegrationTestBase.sol
@@ -46,7 +46,7 @@ import {GatewayFacetsHelper} from "./helpers/GatewayFacetsHelper.sol";
 import {SubnetActorFacetsHelper} from "./helpers/SubnetActorFacetsHelper.sol";
 import {DiamondFacetsHelper} from "./helpers/DiamondFacetsHelper.sol";
 
-import {ActivitySummary} from "../contracts/activities/Activity.sol";
+import {FullActivityRollup, CompressedActivityRollup, Consensus} from "../contracts/activities/Activity.sol";
 import {ValidatorRewarderMap} from "../contracts/examples/ValidatorRewarderMap.sol";
 import {ValidatorRewardFacet} from "../contracts/activities/ValidatorRewardFacet.sol";
 
@@ -934,9 +934,14 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
             blockHash: keccak256(abi.encode(h)),
             nextConfigurationNumber: nextConfigNum - 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({
-                totalActiveValidators: uint64(validators.length),
-                commitment: bytes32(uint256(nextConfigNum))
+            activities: CompressedActivityRollup({
+                consensus: Consensus.CompressedSummary({
+                    stats: Consensus.AggregatedStats({
+                        totalActiveValidators: uint64(validators.length),
+                        totalNumBlocksCommitted: 3
+                    }),
+                    dataRootCommitment: Consensus.MerkleHash.wrap(bytes32(uint256(nextConfigNum)))
+                })
             })
         });
 
@@ -956,7 +961,7 @@ contract IntegrationTestBase is Test, TestParams, TestRegistry, TestSubnetActor,
     function confirmChange(
         address[] memory validators,
         uint256[] memory privKeys,
-        ActivitySummary memory activities
+        CompressedActivityRollup memory activities
     ) internal {
         uint256 n = validators.length;
 
diff --git a/contracts/test/helpers/ActivityHelper.sol b/contracts/test/helpers/ActivityHelper.sol
new file mode 100644
index 0000000000..037db293f9
--- /dev/null
+++ b/contracts/test/helpers/ActivityHelper.sol
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+pragma solidity ^0.8.23;
+
+import {Consensus, CompressedActivityRollup} from "../../contracts/activities/Activity.sol";
+
+library ActivityHelper {
+    function newCompressedActivityRollup(
+        uint64 totalActiveValidators,
+        uint64 totalNumBlocksCommitted,
+        bytes32 detailsRootCommitment
+    ) internal pure returns (CompressedActivityRollup memory compressed) {
+        Consensus.CompressedSummary memory summary = newCompressedSummary(
+            totalActiveValidators,
+            totalNumBlocksCommitted,
+            detailsRootCommitment
+        );
+        compressed.consensus = summary;
+        return compressed;
+    }
+
+    function newCompressedSummary(
+        uint64 totalActiveValidators,
+        uint64 totalNumBlocksCommitted,
+        bytes32 detailsRootCommitment
+    ) internal pure returns (Consensus.CompressedSummary memory summary) {
+        summary.stats.totalActiveValidators = totalActiveValidators;
+        summary.stats.totalNumBlocksCommitted = totalNumBlocksCommitted;
+        summary.dataRootCommitment = Consensus.MerkleHash.wrap(detailsRootCommitment);
+    }
+
+    function wrapBytes32Array(bytes32[] memory data) internal pure returns (Consensus.MerkleHash[] memory wrapped) {
+        uint256 length = data.length;
+
+        if (length == 0) {
+            return wrapped;
+        }
+
+        wrapped = new Consensus.MerkleHash[](data.length);
+        for (uint256 i = 0; i < length; ) {
+            wrapped[i] = Consensus.MerkleHash.wrap(data[i]);
+            unchecked {
+                i++;
+            }
+        }
+
+        return wrapped;
+    }
+}
diff --git a/contracts/test/helpers/MerkleTreeHelper.sol b/contracts/test/helpers/MerkleTreeHelper.sol
index ec166cd81e..f3b911eafe 100644
--- a/contracts/test/helpers/MerkleTreeHelper.sol
+++ b/contracts/test/helpers/MerkleTreeHelper.sol
@@ -34,26 +34,21 @@ library MerkleTreeHelper {
 
     function createMerkleProofsForActivities(
         address[] memory addrs,
-        uint64[] memory blocksMined,
-        bytes[] memory metadatas
+        uint64[] memory blocksMined
     ) internal returns (bytes32, bytes32[][] memory) {
         Merkle merkleTree = new Merkle();
 
         if (addrs.length != blocksMined.length) {
             revert("different array lengths btw blocks mined and addrs");
         }
-        if (addrs.length != metadatas.length) {
-            revert("different array lengths btw metadatas and addrs");
-        }
+
         uint256 len = addrs.length;
 
         bytes32 root;
         bytes32[][] memory proofs = new bytes32[][](len);
         bytes32[] memory data = new bytes32[](len);
         for (uint256 i = 0; i < len; i++) {
-            data[i] = keccak256(
-                bytes.concat(keccak256(abi.encode(addrs[i], blocksMined[i], metadatas[i])))
-            );
+            data[i] = keccak256(bytes.concat(keccak256(abi.encode(addrs[i], blocksMined[i]))));
         }
 
         root = merkleTree.getRoot(data);
diff --git a/contracts/test/helpers/SelectorLibrary.sol b/contracts/test/helpers/SelectorLibrary.sol
index 121b8c3309..9dfe76e4c3 100644
--- a/contracts/test/helpers/SelectorLibrary.sol
+++ b/contracts/test/helpers/SelectorLibrary.sol
@@ -48,7 +48,7 @@ library SelectorLibrary {
         if (keccak256(abi.encodePacked(facetName)) == keccak256(abi.encodePacked("CheckpointingFacet"))) {
             return
                 abi.decode(
-                    hex"0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000553b4e7bf00000000000000000000000000000000000000000000000000000000a21d5ff200000000000000000000000000000000000000000000000000000000ed915e7d000000000000000000000000000000000000000000000000000000009628ea6400000000000000000000000000000000000000000000000000000000ac81837900000000000000000000000000000000000000000000000000000000",
+                    hex"0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000553b4e7bf00000000000000000000000000000000000000000000000000000000a0316672000000000000000000000000000000000000000000000000000000002ea952910000000000000000000000000000000000000000000000000000000036bfdf6700000000000000000000000000000000000000000000000000000000ac81837900000000000000000000000000000000000000000000000000000000",
                     (bytes4[])
                 );
         }
@@ -97,7 +97,7 @@ library SelectorLibrary {
         if (keccak256(abi.encodePacked(facetName)) == keccak256(abi.encodePacked("SubnetActorCheckpointingFacet"))) {
             return
                 abi.decode(
-                    hex"000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000021b6bda5d00000000000000000000000000000000000000000000000000000000cc2dc2b900000000000000000000000000000000000000000000000000000000",
+                    hex"00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000002dcab3d7800000000000000000000000000000000000000000000000000000000cc2dc2b900000000000000000000000000000000000000000000000000000000",
                     (bytes4[])
                 );
         }
@@ -125,7 +125,7 @@ library SelectorLibrary {
         if (keccak256(abi.encodePacked(facetName)) == keccak256(abi.encodePacked("ValidatorRewardFacet"))) {
             return
                 abi.decode(
-                    hex"000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000023cca8af0000000000000000000000000000000000000000000000000000000006be7503e00000000000000000000000000000000000000000000000000000000",
+                    hex"0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000202eca6eb00000000000000000000000000000000000000000000000000000000f9d3434c00000000000000000000000000000000000000000000000000000000",
                     (bytes4[])
                 );
         }
diff --git a/contracts/test/integration/GatewayDiamond.t.sol b/contracts/test/integration/GatewayDiamond.t.sol
index db2f720ab5..69e53166a7 100644
--- a/contracts/test/integration/GatewayDiamond.t.sol
+++ b/contracts/test/integration/GatewayDiamond.t.sol
@@ -39,7 +39,8 @@ import {GatewayFacetsHelper} from "../helpers/GatewayFacetsHelper.sol";
 import {SubnetActorDiamond} from "../../contracts/SubnetActorDiamond.sol";
 import {SubnetActorFacetsHelper} from "../helpers/SubnetActorFacetsHelper.sol";
 
-import {ActivitySummary} from "../../contracts/activities/Activity.sol";
+import {FullActivityRollup, Consensus} from "../../contracts/activities/Activity.sol";
+import {ActivityHelper} from "../helpers/ActivityHelper.sol";
 
 contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeTokenMock {
     using SubnetIDHelper for SubnetID;
@@ -1070,7 +1071,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         BottomUpCheckpoint memory checkpoint = BottomUpCheckpoint({
@@ -1079,7 +1080,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // failed to create a checkpoint with zero membership weight
@@ -1121,7 +1122,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block"),
             nextConfigurationNumber: 2,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.startPrank(FilAddress.SYSTEM_ACTOR);
@@ -1145,7 +1146,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.expectRevert(InvalidCheckpointSource.selector);
@@ -1167,7 +1168,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.prank(caller);
@@ -1214,7 +1215,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 1,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.prank(caller);
@@ -1235,7 +1236,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         BottomUpCheckpoint memory checkpoint2 = BottomUpCheckpoint({
@@ -1244,7 +1245,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // create a checkpoint
@@ -1309,7 +1310,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // create a checkpoint
@@ -1371,7 +1372,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // create a checkpoint
@@ -1455,7 +1456,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // create a checkpoint
@@ -1490,7 +1491,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // create a checkpoint
@@ -1535,7 +1536,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block"),
             nextConfigurationNumber: 1,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // create a checkpoint
@@ -1584,7 +1585,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
                 blockHash: keccak256("block"),
                 nextConfigurationNumber: 1,
                 msgs: new IpcEnvelope[](0),
-                activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+                activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
             });
 
             gatewayDiamond.checkpointer().createBottomUpCheckpoint(checkpoint, membershipRoot, 10);
@@ -1648,7 +1649,7 @@ contract GatewayActorDiamondTest is Test, IntegrationTestBase, SubnetWithNativeT
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 1,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.prank(caller);
diff --git a/contracts/test/integration/GatewayDiamondToken.t.sol b/contracts/test/integration/GatewayDiamondToken.t.sol
index 9b1b4e50bc..3b239b5995 100644
--- a/contracts/test/integration/GatewayDiamondToken.t.sol
+++ b/contracts/test/integration/GatewayDiamondToken.t.sol
@@ -33,7 +33,8 @@ import {IERC20Errors} from "@openzeppelin/contracts/interfaces/draft-IERC6093.so
 
 import {GatewayFacetsHelper} from "../helpers/GatewayFacetsHelper.sol";
 
-import {ActivitySummary} from "../../contracts/activities/Activity.sol";
+import {FullActivityRollup, Consensus} from "../../contracts/activities/Activity.sol";
+import {ActivityHelper} from "../helpers/ActivityHelper.sol";
 
 contract GatewayDiamondTokenTest is Test, IntegrationTestBase {
     using SubnetIDHelper for SubnetID;
@@ -166,7 +167,7 @@ contract GatewayDiamondTokenTest is Test, IntegrationTestBase {
             blockHeight: gatewayDiamond.getter().bottomUpCheckPeriod(),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.prank(address(saDiamond));
@@ -225,7 +226,7 @@ contract GatewayDiamondTokenTest is Test, IntegrationTestBase {
             blockHeight: gatewayDiamond.getter().bottomUpCheckPeriod(),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         // Verify that we received the call and that the recipient has the tokens.
diff --git a/contracts/test/integration/MultiSubnet.t.sol b/contracts/test/integration/MultiSubnet.t.sol
index 7313e35c68..1bf25a3f0d 100644
--- a/contracts/test/integration/MultiSubnet.t.sol
+++ b/contracts/test/integration/MultiSubnet.t.sol
@@ -45,7 +45,8 @@ import {SubnetActorFacetsHelper} from "../helpers/SubnetActorFacetsHelper.sol";
 
 import "forge-std/console.sol";
 
-import {ActivitySummary} from "../../contracts/activities/Activity.sol";
+import {FullActivityRollup, Consensus} from "../../contracts/activities/Activity.sol";
+import {ActivityHelper} from "../helpers/ActivityHelper.sol";
 
 contract MultiSubnetTest is Test, IntegrationTestBase {
     using SubnetIDHelper for SubnetID;
@@ -1351,7 +1352,7 @@ contract MultiSubnetTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: batch.msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.startPrank(FilAddress.SYSTEM_ACTOR);
@@ -1381,7 +1382,7 @@ contract MultiSubnetTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.startPrank(FilAddress.SYSTEM_ACTOR);
diff --git a/contracts/test/integration/SubnetActorDiamond.t.sol b/contracts/test/integration/SubnetActorDiamond.t.sol
index c7a8c30a94..ecfd54c187 100644
--- a/contracts/test/integration/SubnetActorDiamond.t.sol
+++ b/contracts/test/integration/SubnetActorDiamond.t.sol
@@ -43,9 +43,10 @@ import {GatewayFacetsHelper} from "../helpers/GatewayFacetsHelper.sol";
 import {ERC20PresetFixedSupply} from "../helpers/ERC20PresetFixedSupply.sol";
 import {SubnetValidatorGater} from "../../contracts/examples/SubnetValidatorGater.sol";
 
-import {ActivitySummary, ValidatorSummary, BatchClaimProofs, ValidatorClaimProof} from "../../contracts/activities/Activity.sol";
+import {FullActivityRollup, Consensus} from "../../contracts/activities/Activity.sol";
 import {ValidatorRewarderMap} from "../../contracts/examples/ValidatorRewarderMap.sol";
 import {MerkleTreeHelper} from "../helpers/MerkleTreeHelper.sol";
+import {ActivityHelper} from "../helpers/ActivityHelper.sol";
 
 contract SubnetActorDiamondTest is Test, IntegrationTestBase {
     using SubnetIDHelper for SubnetID;
@@ -694,7 +695,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         BottomUpCheckpoint memory checkpointWithIncorrectHeight = BottomUpCheckpoint({
@@ -703,7 +704,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.deal(address(saDiamond), 100 ether);
@@ -804,7 +805,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         BottomUpCheckpoint memory checkpointWithIncorrectHeight = BottomUpCheckpoint({
@@ -813,7 +814,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(1))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.deal(address(saDiamond), 100 ether);
@@ -842,7 +843,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
 
         // submit another again
         checkpoint.blockHeight = 2;
-        checkpoint.activities = ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(2))});
+        checkpoint.activities = ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)));
         hash = keccak256(abi.encode(checkpoint));
 
         for (uint256 i = 0; i < 3; i++) {
@@ -899,7 +900,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(1))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
         require(saDiamond.getter().lastBottomUpCheckpointHeight() == 1, " checkpoint height incorrect");
@@ -912,7 +913,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(2))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
         require(saDiamond.getter().lastBottomUpCheckpointHeight() == 3, " checkpoint height incorrect");
@@ -924,7 +925,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(3))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         vm.expectRevert(BottomUpCheckpointAlreadySubmitted.selector);
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
@@ -936,7 +937,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(4))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         vm.expectRevert(CannotSubmitFutureCheckpoint.selector);
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
@@ -947,7 +948,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(5))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
         require(
@@ -961,7 +962,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(6))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
         require(
@@ -975,7 +976,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(7))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
         require(
@@ -989,7 +990,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(8))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         vm.expectRevert(InvalidCheckpointEpoch.selector);
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
@@ -1000,7 +1001,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(9))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
         require(
@@ -1014,7 +1015,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: new IpcEnvelope[](0),
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(10))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
         submitCheckpointInternal(checkpoint, validators, signatures, keys);
         require(
@@ -1056,7 +1057,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(0)})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         vm.deal(address(saDiamond), 100 ether);
@@ -1100,7 +1101,7 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             blockHash: keccak256("block2"),
             nextConfigurationNumber: 0,
             msgs: msgs,
-            activities: ActivitySummary({totalActiveValidators: 1, commitment: bytes32(uint256(1))})
+            activities: ActivityHelper.newCompressedActivityRollup(1, 3, bytes32(uint256(0)))
         });
 
         hash = keccak256(abi.encode(checkpoint));
@@ -2364,7 +2365,6 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
         powers[3] = 10000;
         saDiamond.manager().setFederatedPower(addrs, pubkeys, powers);
 
-        bytes[] memory metadata = new bytes[](addrs.length);
         uint64[] memory blocksMined = new uint64[](addrs.length);
 
         blocksMined[0] = 1;
@@ -2372,62 +2372,45 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
 
         (bytes32 activityRoot, bytes32[][] memory proofs) = MerkleTreeHelper.createMerkleProofsForActivities(
             addrs,
-            blocksMined,
-            metadata
+            blocksMined
         );
 
-        confirmChange(addrs, privKeys, ActivitySummary({totalActiveValidators: 2, commitment: activityRoot}));
+        confirmChange(addrs, privKeys, ActivityHelper.newCompressedActivityRollup(2, 3, activityRoot));
 
         vm.startPrank(addrs[0]);
         vm.deal(addrs[0], 1 ether);
         saDiamond.validatorReward().claim(
             subnetId,
-            ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
-                validator: addrs[0],
-                blocksCommitted: blocksMined[0],
-                metadata: metadata[0]
-            }),
-            proofs[0]
+            uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
+            Consensus.ValidatorData({validator: addrs[0], blocksCommitted: blocksMined[0]}),
+            ActivityHelper.wrapBytes32Array(proofs[0])
         );
 
         vm.startPrank(addrs[1]);
         vm.deal(addrs[1], 1 ether);
         saDiamond.validatorReward().claim(
             subnetId,
-            ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
-                validator: addrs[1],
-                blocksCommitted: blocksMined[1],
-                metadata: metadata[1]
-            }),
-            proofs[1]
+            uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
+            Consensus.ValidatorData({validator: addrs[1], blocksCommitted: blocksMined[1]}),
+            ActivityHelper.wrapBytes32Array(proofs[1])
         );
 
         vm.startPrank(addrs[2]);
         vm.deal(addrs[2], 1 ether);
         saDiamond.validatorReward().claim(
             subnetId,
-            ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
-                validator: addrs[2],
-                blocksCommitted: blocksMined[2],
-                metadata: metadata[2]
-            }),
-            proofs[2]
+            uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
+            Consensus.ValidatorData({validator: addrs[2], blocksCommitted: blocksMined[2]}),
+            ActivityHelper.wrapBytes32Array(proofs[2])
         );
 
         vm.startPrank(addrs[3]);
         vm.deal(addrs[3], 1 ether);
         saDiamond.validatorReward().claim(
             subnetId,
-            ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
-                validator: addrs[3],
-                blocksCommitted: blocksMined[3],
-                metadata: metadata[3]
-            }),
-            proofs[3]
+            uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
+            Consensus.ValidatorData({validator: addrs[3], blocksCommitted: blocksMined[3]}),
+            ActivityHelper.wrapBytes32Array(proofs[3])
         );
 
         // check
@@ -2472,7 +2455,6 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             saDiamond.manager().setFederatedPower(addrs, pubkeys, powers);
         }
 
-        bytes[] memory metadata = new bytes[](addrs.length);
         uint64[] memory blocksMined = new uint64[](addrs.length);
 
         blocksMined[0] = 1;
@@ -2480,55 +2462,41 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
 
         (bytes32 activityRoot1, bytes32[][] memory proofs1) = MerkleTreeHelper.createMerkleProofsForActivities(
             addrs,
-            blocksMined,
-            metadata
+            blocksMined
         );
 
         (bytes32 activityRoot2, bytes32[][] memory proofs2) = MerkleTreeHelper.createMerkleProofsForActivities(
             addrs,
-            blocksMined,
-            metadata
+            blocksMined
         );
 
-        confirmChange(addrs, privKeys, ActivitySummary({totalActiveValidators: 2, commitment: activityRoot1}));
-        confirmChange(addrs, privKeys, ActivitySummary({totalActiveValidators: 2, commitment: activityRoot2}));
+        confirmChange(addrs, privKeys, ActivityHelper.newCompressedActivityRollup(2, 3, activityRoot1));
+        confirmChange(addrs, privKeys, ActivityHelper.newCompressedActivityRollup(2, 3, activityRoot2));
 
         vm.startPrank(addrs[0]);
         vm.deal(addrs[0], 1 ether);
 
-        BatchClaimProofs[] memory batchProofs = new BatchClaimProofs[](1);
-        ValidatorClaimProof[] memory claimProofs = new ValidatorClaimProof[](2);
-        claimProofs[0] = ValidatorClaimProof({
-            summary: ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
-                validator: addrs[0],
-                blocksCommitted: blocksMined[0],
-                metadata: metadata[0]
-            }),
-            proof: proofs1[0]
-        });
-        claimProofs[1] = ValidatorClaimProof({
-            summary: ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()) * 2,
-                validator: addrs[0],
-                blocksCommitted: blocksMined[0],
-                metadata: metadata[0]
-            }),
-            proof: proofs2[0]
-        });
+        Consensus.ValidatorClaim[] memory claimProofs = new Consensus.ValidatorClaim[](2);
+        uint64[] memory checkpointHeights = new uint64[](2);
+
+        checkpointHeights[0] = uint64(gatewayDiamond.getter().bottomUpCheckPeriod());
+        checkpointHeights[1] = uint64(gatewayDiamond.getter().bottomUpCheckPeriod()) * 2;
 
-        batchProofs[0] = BatchClaimProofs({
-            subnetId: subnetId,
-            proofs: claimProofs
+        claimProofs[0] = Consensus.ValidatorClaim({
+            data: Consensus.ValidatorData({validator: addrs[0], blocksCommitted: blocksMined[0]}),
+            proof: ActivityHelper.wrapBytes32Array(proofs1[0])
+        });
+        claimProofs[1] = Consensus.ValidatorClaim({
+            data: Consensus.ValidatorData({validator: addrs[0], blocksCommitted: blocksMined[0]}),
+            proof: ActivityHelper.wrapBytes32Array(proofs2[0])
         });
 
-        saDiamond.validatorReward().batchClaim(batchProofs);
+        saDiamond.validatorReward().batchSubnetClaim(subnetId, checkpointHeights, claimProofs);
 
         // check
         assert(m.blocksCommitted(addrs[0]) == 2);
     }
 
-
     function testGatewayDiamond_ValidatorBatchClaimMiningReward_NoDoubleClaim() public {
         ValidatorRewarderMap m = new ValidatorRewarderMap();
         {
@@ -2564,7 +2532,6 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
             saDiamond.manager().setFederatedPower(addrs, pubkeys, powers);
         }
 
-        bytes[] memory metadata = new bytes[](addrs.length);
         uint64[] memory blocksMined = new uint64[](addrs.length);
 
         blocksMined[0] = 1;
@@ -2572,50 +2539,36 @@ contract SubnetActorDiamondTest is Test, IntegrationTestBase {
 
         (bytes32 activityRoot1, bytes32[][] memory proofs1) = MerkleTreeHelper.createMerkleProofsForActivities(
             addrs,
-            blocksMined,
-            metadata
+            blocksMined
         );
-
         (bytes32 activityRoot2, bytes32[][] memory proofs2) = MerkleTreeHelper.createMerkleProofsForActivities(
             addrs,
-            blocksMined,
-            metadata
+            blocksMined
         );
 
-        confirmChange(addrs, privKeys, ActivitySummary({totalActiveValidators: 2, commitment: activityRoot1}));
-        confirmChange(addrs, privKeys, ActivitySummary({totalActiveValidators: 2, commitment: activityRoot2}));
+        confirmChange(addrs, privKeys, ActivityHelper.newCompressedActivityRollup(2, 3, activityRoot1));
+        confirmChange(addrs, privKeys, ActivityHelper.newCompressedActivityRollup(2, 3, activityRoot2));
 
         vm.startPrank(addrs[0]);
         vm.deal(addrs[0], 1 ether);
 
-        BatchClaimProofs[] memory batchProofs = new BatchClaimProofs[](1);
-        ValidatorClaimProof[] memory claimProofs = new ValidatorClaimProof[](2);
-        claimProofs[0] = ValidatorClaimProof({
-            summary: ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
-                validator: addrs[0],
-                blocksCommitted: blocksMined[0],
-                metadata: metadata[0]
-            }),
-            proof: proofs1[0]
-        });
-        claimProofs[1] = ValidatorClaimProof({
-            summary: ValidatorSummary({
-                checkpointHeight: uint64(gatewayDiamond.getter().bottomUpCheckPeriod()),
-                validator: addrs[0],
-                blocksCommitted: blocksMined[0],
-                metadata: metadata[0]
-            }),
-            proof: proofs1[0]
-        });
+        Consensus.ValidatorClaim[] memory claimProofs = new Consensus.ValidatorClaim[](2);
+        uint64[] memory heights = new uint64[](2);
 
-        batchProofs[0] = BatchClaimProofs({
-            subnetId: subnetId,
-            proofs: claimProofs
+        heights[0] = uint64(gatewayDiamond.getter().bottomUpCheckPeriod());
+        heights[1] = uint64(gatewayDiamond.getter().bottomUpCheckPeriod());
+
+        claimProofs[0] = Consensus.ValidatorClaim({
+            data: Consensus.ValidatorData({validator: addrs[0], blocksCommitted: blocksMined[0]}),
+            proof: ActivityHelper.wrapBytes32Array(proofs1[0])
+        });
+        claimProofs[1] = Consensus.ValidatorClaim({
+            data: Consensus.ValidatorData({validator: addrs[0], blocksCommitted: blocksMined[0]}),
+            proof: ActivityHelper.wrapBytes32Array(proofs2[0])
         });
 
         vm.expectRevert(ValidatorAlreadyClaimed.selector);
-        saDiamond.validatorReward().batchClaim(batchProofs);
+        saDiamond.validatorReward().batchSubnetClaim(subnetId, heights, claimProofs);
     }
 
     // -----------------------------------------------------------------------------------------------------------------
diff --git a/docs/fendermint/diagrams/activity_rollup1.png b/docs/fendermint/diagrams/activity_rollup1.png
new file mode 100644
index 0000000000..6a2dc98cb7
Binary files /dev/null and b/docs/fendermint/diagrams/activity_rollup1.png differ
diff --git a/docs/fendermint/subnet_activities.md b/docs/fendermint/subnet_activities.md
new file mode 100644
index 0000000000..cf2c6d0383
--- /dev/null
+++ b/docs/fendermint/subnet_activities.md
@@ -0,0 +1,78 @@
+# Subnet activities roll up
+
+## Overview
+This doc introduces the notion of child subnet rolls up its activities through bottom-up checkpoints to its parent. 
+This is a mechanism to synthesise and propagate selective information about the activity that occurred inside a subnet to the parent.
+The definition of `Activity` can be application specific, but generally, it represents critical information about the child subnet that
+is valuable and can be acted upon in the parent(if there is one). Some sample activities could be:
+- The blocks mined by each validator
+- The total number of blocks mined in between bottom up checkpoints.
+- ...
+
+The parent can choose to either relay this information up the hierarchy, or consume the incoming report for some effect, such as:
+- rewarding validators by minting a token
+- rebalancing the validator set based on performance metrics
+- tracking subnet state
+- ...
+
+For each application, it is possible to define its own `Activity` struct to handle different scenarios, but IPC tracks 
+the blocks mined by each validator and total number of blocks mined in between bottom up checkpoints out of the box.
+
+## Overall flow
+The key idea is that child subnet tracks these activities and submits `commitment` to the parent subnet through bottom up
+checkpoints. In the parent to trigger downstream effects, one needs to provide proofs to interact with the activities in the child subnet. 
+As an example, consider validator rewarding. The commitment is a merkle root over the blocks mined by each validator. This root is carried 
+to the parent as part of the bottom up checkpoint. The validator can claim its reward in the parent subnet by submitting a 
+merkle proof. The merkle proof can be deduced from child subnet.
+
+The key components are shown below:
+![Activity Rollup Key Components](diagrams/activity_rollup1.png)
+- Activity tracker actor: A fvm actor that tracks and aggregates the blockchain's activities. It allows querying and purging of subnet activities. 
+- Bottom up checkpoint: The bottom up checkpoint contains the commitment to subnet activities.
+- Diamond facets: The different diamond facets to handle the follow-ups in the parent. IPC ships with `ValidatorRewardFacet` by default, but one can choose not to deploy it if not needed.
+
+## Key data models
+The overall activity struct submitted in the child subnet is FullActivityRollUp. It carries a set of aggregated reports on various aspects of the 
+activity that took place in the subnet between the previous checkpoint and the checkpoint this summary is committed into. If this is the 
+first checkpoint, the summary contains information about the subnet's activity since genesis.
+
+The first report we introduce is the consensus level report. This report contains:
+- Aggregated block mining stats: 
+  - Total active validators: the total number of unique validators that have mined within this period.
+  - Total number of blocks committed: the total number of blocks committed by all validators during this period.
+- Validator data: Contains an array of addresses and blocks mined for each validator. One can add more fields to track more activities, such as uptime metrics .
+
+We emit the full activities roll up as a local event, `ActivityRollupRecorded`, in the subnet, for stakeholders (e.g. validators) to monitor and present 
+any relevant payloads up in the hierarchy to trigger downstream effects.
+
+Over time, `FullActivityRollUp` can bloat, e.g. if the validator count in a subnet grows. When combined with xnet messages, the checkpoint size can become large, 
+which has detrimental effects on gas costs at the parent, and could even potentially exceed message size limits. Therefore, instead of embedding 
+the payloads in the checkpoint, we use a compressed summary in the bottom up checkpoint: CompressedActivityRollup. This struct contains the distilled information
+that is critical to the parent subnet. At the moment, it contains the consensus level summary for validator rewarding.
+
+## Activity tacking in child subnet
+TODO
+
+## Roll up in action
+Once the activities are tracked in the child subnet, fendermint will generate the compressed summary and attach it as part of the bottom up checkpoint.
+The generation of the compressed summary for each report could be different and generally application specific.
+Once a quorum is reached in the child subnet, the relayer will submit the bottom up checkpoint to the parent subnet actor. Since the compressed 
+summary is part of the bottom up checkpoint, the compressed summary is forwarded to the parent subnet.
+
+## Validator rewards
+For IPC, the validator rewarding mechanism is shipped out of the box. When the bottom up checkpoint is constructed, fendermint will query all 
+validator mining details from the activity tracker. It aggregates the number of blocks mined for each validator and merklize over the array. 
+Note that the validators are sorted by their address and blocks mined for unique ordering.
+Since the `FullActivityRollUp` contains all validators' mining activities, validator can filter the `ActivityRollupRecorded` events against 
+fendermint's eth rpc endpoints to obtain the full list of activities to derive the merkle proof. There is an `ipc-cli` command to help validators 
+claim the reward.
+
+The bottom up checkpoint submitted in the parent subnet will initialize a new reward distribution for that checkpoint height. When a validator claims 
+the reward, the subnet actor will verify the merkle proof for the pending checkpoint height, and call the ValidatorRewarder implementation if it 
+succeeds, marking the fragment as claimed in its state, so it cannot be double claimed.
+
+IPC `ValidatorRewarderFacet` tracks the claim history of each validator to avoid double claiming. However, the detailed reward distribution 
+logic is actually handled by a custom contract, namely `IValidatorRewarder`. When the subnet is created, the creator can specify the address 
+of the validator rewarder implementation and when eligible validator claims the reward, the subnet actor will pass the validator address and 
+blocks mined to the rewarder implementation. As an example, the rewarder implementation could mint erc20 based on the parameters sent from subnet 
+actor.
\ No newline at end of file
diff --git a/extras/axelar-token/foundry.toml b/extras/axelar-token/foundry.toml
index bd8ca5d7e8..e06f33cc00 100644
--- a/extras/axelar-token/foundry.toml
+++ b/extras/axelar-token/foundry.toml
@@ -5,4 +5,5 @@ libs = ["node_modules", "lib"]
 fs_permissions = [{ access = "read-write", path = "./out"}]
 remappings = [
     "@consensus-shipyard/=node_modules/@consensus-shipyard/"
-]
\ No newline at end of file
+]
+allow_paths = ["../../contracts"]
\ No newline at end of file
diff --git a/extras/linked-token/foundry.toml b/extras/linked-token/foundry.toml
index 57993af93c..4409ba7739 100644
--- a/extras/linked-token/foundry.toml
+++ b/extras/linked-token/foundry.toml
@@ -7,4 +7,4 @@ remappings = [
     "@ipc/=node_modules/@consensus-shipyard/ipc-contracts/",
     ## this murky remapping is only needed transitively for testing; we should try to get rid of this.
     "murky/=node_modules/@consensus-shipyard/ipc-contracts/lib/murky/src/",
-]
+]
\ No newline at end of file
diff --git a/extras/linked-token/test/MultiSubnetTest.t.sol b/extras/linked-token/test/MultiSubnetTest.t.sol
index 38143279f9..26d7d529b8 100644
--- a/extras/linked-token/test/MultiSubnetTest.t.sol
+++ b/extras/linked-token/test/MultiSubnetTest.t.sol
@@ -28,6 +28,7 @@ import {GatewayGetterFacet} from "@ipc/contracts/gateway/GatewayGetterFacet.sol"
 import {SubnetActorCheckpointingFacet} from "@ipc/contracts/subnet/SubnetActorCheckpointingFacet.sol";
 import {CheckpointingFacet} from "@ipc/contracts/gateway/router/CheckpointingFacet.sol";
 import {FvmAddressHelper} from "@ipc/contracts/lib/FvmAddressHelper.sol";
+import {Consensus, CompressedActivityRollup} from "@ipc/contracts/activities/Activity.sol";
 import {IpcEnvelope, BottomUpMsgBatch, BottomUpCheckpoint, ParentFinality, IpcMsgKind, ResultMsg, CallMsg} from "@ipc/contracts/structs/CrossNet.sol";
 import {SubnetIDHelper} from "@ipc/contracts/lib/SubnetIDHelper.sol";
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
@@ -383,7 +384,16 @@ contract MultiSubnetTest is IntegrationTestBase {
             blockHeight: batch.blockHeight,
             blockHash: keccak256("block1"),
             nextConfigurationNumber: 0,
-            msgs: batch.msgs
+            msgs: batch.msgs,
+            activities: CompressedActivityRollup({
+                consensus: Consensus.CompressedSummary({
+                stats: Consensus.AggregatedStats({
+                    totalActiveValidators: 1,
+                    totalNumBlocksCommitted: 1
+                }),
+                dataRootCommitment: Consensus.MerkleHash.wrap(bytes32(0))
+            })
+            })
         });
 
         vm.startPrank(FilAddress.SYSTEM_ACTOR);
diff --git a/fendermint/actors/activity-tracker/Cargo.toml b/fendermint/actors/activity-tracker/Cargo.toml
index 886262036e..0c06eaa258 100644
--- a/fendermint/actors/activity-tracker/Cargo.toml
+++ b/fendermint/actors/activity-tracker/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "fendermint_actor_activity_tracker"
-description = "Tracks fendermint block mining activities"
+description = "Tracks subnet activity and generates rollups to submit to the parent in checkpoints"
 license.workspace = true
 edition.workspace = true
 authors.workspace = true
@@ -14,7 +14,6 @@ crate-type = ["cdylib", "lib"]
 [dependencies]
 anyhow = { workspace = true }
 cid = { workspace = true }
-fil_actor_eam = { workspace = true }
 fil_actors_runtime = { workspace = true }
 fvm_ipld_blockstore = { workspace = true }
 fvm_ipld_encoding = { workspace = true }
@@ -24,6 +23,7 @@ multihash = { workspace = true }
 num-derive = { workspace = true }
 num-traits = { workspace = true }
 serde = { workspace = true }
+serde_tuple = { workspace = true }
 hex-literal = { workspace = true }
 frc42_dispatch = { workspace = true }
 
diff --git a/fendermint/actors/activity-tracker/src/lib.rs b/fendermint/actors/activity-tracker/src/lib.rs
index 791bc688aa..f8f84faa9b 100644
--- a/fendermint/actors/activity-tracker/src/lib.rs
+++ b/fendermint/actors/activity-tracker/src/lib.rs
@@ -1,21 +1,19 @@
-// Copyright 2021-2023 Protocol Labs
+// Copyright 2021-2024 Protocol Labs
 // SPDX-License-Identifier: Apache-2.0, MIT
 
-use fil_actors_runtime::actor_error;
+use crate::state::ConsensusData;
+pub use crate::state::State;
+use crate::types::FullActivityRollup;
 use fil_actors_runtime::builtin::singletons::SYSTEM_ACTOR_ADDR;
 use fil_actors_runtime::runtime::{ActorCode, Runtime};
-use fil_actors_runtime::{actor_dispatch, ActorError};
-use fvm_ipld_encoding::tuple::*;
-use fvm_shared::address::Address;
-use fvm_shared::clock::ChainEpoch;
+use fil_actors_runtime::{actor_dispatch, ActorError, EAM_ACTOR_ID};
+use fil_actors_runtime::{actor_error, DEFAULT_HAMT_CONFIG};
+use fvm_shared::address::{Address, Payload};
 use fvm_shared::METHOD_CONSTRUCTOR;
 use num_derive::FromPrimitive;
-use serde::{Deserialize, Serialize};
-
-pub use crate::state::State;
-pub use crate::state::ValidatorSummary;
 
 mod state;
+pub mod types;
 
 #[cfg(feature = "fil-actor")]
 fil_actors_runtime::wasm_trampoline!(ActivityTrackerActor);
@@ -24,64 +22,82 @@ pub const IPC_ACTIVITY_TRACKER_ACTOR_NAME: &str = "activity_tracker";
 
 pub struct ActivityTrackerActor;
 
-#[derive(Deserialize_tuple, Serialize_tuple, Debug, Clone)]
-pub struct BlockedMinedParams {
-    pub validator: Address,
-}
-
-#[derive(Deserialize, Serialize, Debug, Clone)]
-pub struct GetActivitiesResult {
-    pub activities: Vec<ValidatorSummary>,
-    pub start_height: ChainEpoch,
-}
-
 #[derive(FromPrimitive)]
 #[repr(u64)]
 pub enum Method {
     Constructor = METHOD_CONSTRUCTOR,
-    BlockMined = frc42_dispatch::method_hash!("BlockMined"),
-    GetActivities = frc42_dispatch::method_hash!("GetActivities"),
-    PurgeActivities = frc42_dispatch::method_hash!("PurgeActivities"),
+    RecordBlockCommitted = frc42_dispatch::method_hash!("RecordBlockCommitted"),
+    CommitActivity = frc42_dispatch::method_hash!("CommitActivity"),
+    PendingActivity = frc42_dispatch::method_hash!("PendingActivity"),
+}
+
+trait ActivityTracker {
+    /// Hook for the consensus layer to report that the validator committed a new block.
+    fn record_block_committed(rt: &impl Runtime, validator: Address) -> Result<(), ActorError>;
+
+    /// Commits the pending activity into an activity rollup.
+    /// Currently, this constructs an activity rollup from the internal state, and then resets the internal state.
+    /// In the future, this might actually write the activity rollup to the gateway directly, instead of relying on the client to move it around.
+    /// Returns the activity rollup as a Solidity ABI-encoded type, in raw byte form.
+    fn commit_activity(rt: &impl Runtime) -> Result<FullActivityRollup, ActorError>;
+
+    /// Queries the activity that has been accumulated since the last commit, and is pending a flush.
+    fn pending_activity(rt: &impl Runtime) -> Result<FullActivityRollup, ActorError>;
 }
 
 impl ActivityTrackerActor {
     pub fn constructor(rt: &impl Runtime) -> Result<(), ActorError> {
         let st = State::new(rt.store())?;
         rt.create(&st)?;
-
         Ok(())
     }
+}
 
-    pub fn block_mined(rt: &impl Runtime, block: BlockedMinedParams) -> Result<(), ActorError> {
+impl ActivityTracker for ActivityTrackerActor {
+    fn record_block_committed(rt: &impl Runtime, validator: Address) -> Result<(), ActorError> {
         rt.validate_immediate_caller_is(std::iter::once(&SYSTEM_ACTOR_ADDR))?;
 
+        // Reject non-f410 addresses.
+        if !matches!(validator.payload(), Payload::Delegated(d) if d.namespace() == EAM_ACTOR_ID && d.subaddress().len() == 20)
+        {
+            return Err(
+                actor_error!(illegal_argument; "validator address must be a valid f410 address"),
+            );
+        }
+
         rt.transaction(|st: &mut State, rt| {
-            st.incr_validator_block_committed(rt, &block.validator)
-        })?;
+            let mut consensus =
+                ConsensusData::load(rt.store(), &st.consensus, DEFAULT_HAMT_CONFIG, "consensus")?;
 
-        Ok(())
+            let mut v = consensus.get(&validator)?.cloned().unwrap_or_default();
+            v.blocks_committed += 1;
+            consensus.set(&validator, v)?;
+
+            st.consensus = consensus.flush()?;
+
+            Ok(())
+        })
     }
 
-    pub fn purge_activities(rt: &impl Runtime) -> Result<(), ActorError> {
+    fn commit_activity(rt: &impl Runtime) -> Result<FullActivityRollup, ActorError> {
         rt.validate_immediate_caller_is(std::iter::once(&SYSTEM_ACTOR_ADDR))?;
 
+        // Obtain the pending rollup from state.
+        let rollup = rt.state::<State>()?.pending_activity_rollup(rt)?;
+
         rt.transaction(|st: &mut State, rt| {
-            st.purge_validator_block_committed(rt)?;
-            st.reset_start_height(rt)
+            st.consensus = ConsensusData::flush_empty(rt.store(), DEFAULT_HAMT_CONFIG)?;
+            st.tracking_since = rt.curr_epoch();
+            Ok(())
         })?;
 
-        Ok(())
+        Ok(rollup)
     }
 
-    pub fn get_activities(rt: &impl Runtime) -> Result<GetActivitiesResult, ActorError> {
+    fn pending_activity(rt: &impl Runtime) -> Result<FullActivityRollup, ActorError> {
         rt.validate_immediate_caller_accept_any()?;
 
-        let state: State = rt.state()?;
-        let activities = state.validator_activities(rt)?;
-        Ok(GetActivitiesResult {
-            activities,
-            start_height: state.start_height,
-        })
+        rt.state::<State>()?.pending_activity_rollup(rt)
     }
 }
 
@@ -94,8 +110,8 @@ impl ActorCode for ActivityTrackerActor {
 
     actor_dispatch! {
         Constructor => constructor,
-        BlockMined => block_mined,
-        GetActivities => get_activities,
-        PurgeActivities => purge_activities,
+        RecordBlockCommitted => record_block_committed,
+        CommitActivity => commit_activity,
+        PendingActivity => pending_activity,
     }
 }
diff --git a/fendermint/actors/activity-tracker/src/state.rs b/fendermint/actors/activity-tracker/src/state.rs
index 7377b78b37..b7ae7b88bd 100644
--- a/fendermint/actors/activity-tracker/src/state.rs
+++ b/fendermint/actors/activity-tracker/src/state.rs
@@ -1,6 +1,7 @@
 // Copyright 2021-2023 Protocol Labs
 // SPDX-License-Identifier: Apache-2.0, MIT
 
+use crate::types::{FullActivityRollup, ValidatorStats};
 use cid::Cid;
 use fil_actors_runtime::runtime::Runtime;
 use fil_actors_runtime::{ActorError, Map2, DEFAULT_HAMT_CONFIG};
@@ -9,100 +10,45 @@ use fvm_shared::address::Address;
 use fvm_shared::clock::ChainEpoch;
 use serde::{Deserialize, Serialize};
 
-pub type BlockCommittedMap<BS> = Map2<BS, Address, BlockCommitted>;
-pub type BlockCommitted = u64;
-
-#[derive(Deserialize, Serialize, Debug, Clone)]
-pub struct ValidatorSummary {
-    pub validator: Address,
-    pub block_committed: BlockCommitted,
-    pub metadata: Vec<u8>,
-}
-
 #[derive(Deserialize, Serialize, Debug, Clone)]
 pub struct State {
-    pub start_height: ChainEpoch,
-    pub blocks_committed: Cid, // BlockCommittedMap
+    pub tracking_since: ChainEpoch,
+    pub consensus: Cid, // ConsensusData
 }
 
+pub type ConsensusData<BS> = Map2<BS, Address, ValidatorStats>;
+
 impl State {
     pub fn new<BS: Blockstore>(store: &BS) -> Result<State, ActorError> {
-        let mut deployers_map = BlockCommittedMap::empty(store, DEFAULT_HAMT_CONFIG, "empty");
-        Ok(State {
-            start_height: 0,
-            blocks_committed: deployers_map.flush()?,
-        })
-    }
-
-    pub fn reset_start_height(&mut self, rt: &impl Runtime) -> Result<(), ActorError> {
-        self.start_height = rt.curr_epoch();
-        Ok(())
-    }
-
-    pub fn purge_validator_block_committed(&mut self, rt: &impl Runtime) -> Result<(), ActorError> {
-        let all_validators = self.validator_activities(rt)?;
-        let mut validators = BlockCommittedMap::load(
-            rt.store(),
-            &self.blocks_committed,
-            DEFAULT_HAMT_CONFIG,
-            "verifiers",
-        )?;
-
-        for v in all_validators {
-            validators.delete(&v.validator)?;
-        }
-
-        self.blocks_committed = validators.flush()?;
-
-        Ok(())
-    }
-
-    pub fn incr_validator_block_committed(
-        &mut self,
-        rt: &impl Runtime,
-        validator: &Address,
-    ) -> Result<(), ActorError> {
-        let mut validators = BlockCommittedMap::load(
-            rt.store(),
-            &self.blocks_committed,
-            DEFAULT_HAMT_CONFIG,
-            "verifiers",
-        )?;
-
-        let v = if let Some(v) = validators.get(validator)? {
-            *v + 1
-        } else {
-            1
+        let state = State {
+            tracking_since: 0,
+            consensus: ConsensusData::flush_empty(store, DEFAULT_HAMT_CONFIG)?,
         };
-
-        validators.set(validator, v)?;
-
-        self.blocks_committed = validators.flush()?;
-
-        Ok(())
+        Ok(state)
     }
 
-    pub fn validator_activities(
+    /// Returns the pending activity rollup.
+    pub fn pending_activity_rollup(
         &self,
         rt: &impl Runtime,
-    ) -> Result<Vec<ValidatorSummary>, ActorError> {
-        let mut result = vec![];
-
-        let validators = BlockCommittedMap::load(
-            rt.store(),
-            &self.blocks_committed,
-            DEFAULT_HAMT_CONFIG,
-            "verifiers",
-        )?;
-        validators.for_each(|k, v| {
-            result.push(ValidatorSummary {
-                validator: k,
-                block_committed: *v,
-                metadata: vec![],
-            });
+    ) -> Result<FullActivityRollup, ActorError> {
+        let consensus = {
+            let cid = &rt.state::<State>()?.consensus;
+            ConsensusData::load(rt.store(), cid, DEFAULT_HAMT_CONFIG, "consensus")
+        }?;
+
+        // Populate the rollup struct.
+        let mut rollup = FullActivityRollup::default();
+        consensus.for_each(|validator_addr, validator_stats| {
+            rollup.consensus.stats.total_active_validators += 1;
+            rollup.consensus.stats.total_num_blocks_committed += validator_stats.blocks_committed;
+            rollup
+                .consensus
+                .data
+                .insert(validator_addr, validator_stats.clone());
             Ok(())
         })?;
 
-        Ok(result)
+        Ok(rollup)
     }
 }
diff --git a/fendermint/actors/activity-tracker/src/types.rs b/fendermint/actors/activity-tracker/src/types.rs
new file mode 100644
index 0000000000..3ad297d4f5
--- /dev/null
+++ b/fendermint/actors/activity-tracker/src/types.rs
@@ -0,0 +1,28 @@
+// Copyright 2021-2023 Protocol Labs
+// SPDX-License-Identifier: Apache-2.0, MIT
+
+use fvm_ipld_encoding::tuple::{Deserialize_tuple, Serialize_tuple};
+use fvm_shared::address::Address;
+use std::collections::HashMap;
+
+#[derive(Deserialize_tuple, Serialize_tuple, Debug, Clone, PartialEq, Eq, Default)]
+pub struct AggregatedStats {
+    pub total_active_validators: u64,
+    pub total_num_blocks_committed: u64,
+}
+
+#[derive(Deserialize_tuple, Serialize_tuple, Debug, Clone, PartialEq, Eq, Default)]
+pub struct FullConsensusSummary {
+    pub stats: AggregatedStats,
+    pub data: HashMap<Address, ValidatorStats>,
+}
+
+#[derive(Deserialize_tuple, Serialize_tuple, Debug, Clone, PartialEq, Eq, Default)]
+pub struct FullActivityRollup {
+    pub consensus: FullConsensusSummary,
+}
+
+#[derive(Deserialize_tuple, Serialize_tuple, Debug, Clone, PartialEq, Eq, Default)]
+pub struct ValidatorStats {
+    pub blocks_committed: u64,
+}
diff --git a/fendermint/eth/api/Cargo.toml b/fendermint/eth/api/Cargo.toml
index c1b675bb79..997bb4496d 100644
--- a/fendermint/eth/api/Cargo.toml
+++ b/fendermint/eth/api/Cargo.toml
@@ -32,7 +32,7 @@ tokio = { workspace = true }
 tower-http = { workspace = true }
 
 fil_actors_evm_shared = { workspace = true }
-fvm_shared = { workspace = true }
+fvm_shared = { workspace = true, features  = ["crypto"] }
 fvm_ipld_encoding = { workspace = true }
 
 fendermint_crypto = { path = "../../crypto" }
diff --git a/fendermint/eth/api/src/apis/eth.rs b/fendermint/eth/api/src/apis/eth.rs
index 7e0af92136..01ba886f80 100644
--- a/fendermint/eth/api/src/apis/eth.rs
+++ b/fendermint/eth/api/src/apis/eth.rs
@@ -1016,6 +1016,7 @@ where
 
                 // Filter by address.
                 if !addrs.is_empty() && addrs.intersection(&emitters).next().is_none() {
+                    height = height.increment();
                     continue;
                 }
 
diff --git a/fendermint/testing/contract-test/Cargo.toml b/fendermint/testing/contract-test/Cargo.toml
index 405b8c22fc..60f82f8a7f 100644
--- a/fendermint/testing/contract-test/Cargo.toml
+++ b/fendermint/testing/contract-test/Cargo.toml
@@ -13,7 +13,7 @@ anyhow = { workspace = true }
 cid = { workspace = true }
 ethers = { workspace = true }
 fvm = { workspace = true }
-fvm_shared = { workspace = true }
+fvm_shared = { workspace = true, features  = ["crypto"] }
 fvm_ipld_blockstore = { workspace = true }
 hex = { workspace = true }
 rand = { workspace = true }
diff --git a/fendermint/vm/actor_interface/src/ipc.rs b/fendermint/vm/actor_interface/src/ipc.rs
index be5248fb55..572df6af76 100644
--- a/fendermint/vm/actor_interface/src/ipc.rs
+++ b/fendermint/vm/actor_interface/src/ipc.rs
@@ -118,6 +118,11 @@ lazy_static! {
                             name: "OwnershipFacet",
                             abi: ia::ownership_facet::OWNERSHIPFACET_ABI.to_owned(),
                         },
+                        EthFacet {
+                            name: "ValidatorRewardFacet",
+                            abi: ia::validator_reward_facet::VALIDATORREWARDFACET_ABI.to_owned(),
+                        },
+                        // ========== IF YOU WANT TO ADD FACET FOR SUBNET, APPEND HERE ==========
                         // The registry has its own facets:
                         // https://github.com/consensus-shipyard/ipc-solidity-actors/blob/b01a2dffe367745f55111a65536a3f6fea9165f5/scripts/deploy-registry.template.ts#L58-L67
                         EthFacet {
@@ -129,10 +134,6 @@ lazy_static! {
                             name: "SubnetGetterFacet",
                             abi: ia::subnet_getter_facet::SUBNETGETTERFACET_ABI.to_owned(),
                         },
-                        EthFacet {
-                            name: "ValidatorRewardFacet",
-                            abi: ia::validator_reward_facet::VALIDATORREWARDFACET_ABI.to_owned(),
-                        },
                     ],
                 },
             ),
@@ -546,7 +547,7 @@ pub mod subnet {
             let param_type = BottomUpCheckpoint::param_type();
 
             // Captured value of `abi.encode` in Solidity.
-            let expected_abi: Bytes = "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".parse().unwrap();
+            let expected_abi: Bytes = "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".parse().unwrap();
 
             // XXX: It doesn't work with `decode_whole`.
             let expected_tokens =
diff --git a/fendermint/vm/interpreter/Cargo.toml b/fendermint/vm/interpreter/Cargo.toml
index 39c6f2e345..a82fae6e14 100644
--- a/fendermint/vm/interpreter/Cargo.toml
+++ b/fendermint/vm/interpreter/Cargo.toml
@@ -83,6 +83,7 @@ fendermint_testing = { path = "../../testing", features = ["golden"] }
 fvm = { workspace = true, features = ["arb", "testing"] }
 fendermint_vm_genesis = { path = "../genesis", features = ["arb"] }
 multihash = { workspace = true }
+hex = { workspace = true }
 
 [features]
 default = []
diff --git a/fendermint/vm/interpreter/src/fvm/activities/actor.rs b/fendermint/vm/interpreter/src/fvm/activities/actor.rs
deleted file mode 100644
index 87ddad1cb4..0000000000
--- a/fendermint/vm/interpreter/src/fvm/activities/actor.rs
+++ /dev/null
@@ -1,105 +0,0 @@
-// Copyright 2022-2024 Protocol Labs
-// SPDX-License-Identifier: Apache-2.0, MIT
-
-use crate::fvm::activities::{ActivityDetails, BlockMined, ValidatorActivityTracker};
-use crate::fvm::state::FvmExecState;
-use crate::fvm::FvmMessage;
-use anyhow::Context;
-use fendermint_actor_activity_tracker::{GetActivitiesResult, ValidatorSummary};
-use fendermint_vm_actor_interface::activity::ACTIVITY_TRACKER_ACTOR_ADDR;
-use fendermint_vm_actor_interface::eam::EthAddress;
-use fendermint_vm_actor_interface::system;
-use fvm::executor::ApplyRet;
-use fvm_ipld_blockstore::Blockstore;
-use fvm_shared::clock::ChainEpoch;
-
-pub struct ActorActivityTracker<'a, DB: Blockstore + Clone + 'static> {
-    pub(crate) executor: &'a mut FvmExecState<DB>,
-    pub(crate) epoch: ChainEpoch,
-}
-
-impl<'a, DB: Blockstore + Clone + 'static> ValidatorActivityTracker
-    for ActorActivityTracker<'a, DB>
-{
-    type ValidatorSummaryDetail = ValidatorSummary;
-
-    fn track_block_mined(&mut self, block: BlockMined) -> anyhow::Result<()> {
-        let params = fendermint_actor_activity_tracker::BlockedMinedParams {
-            validator: fvm_shared::address::Address::from(EthAddress::from(block.validator)),
-        };
-
-        let msg = FvmMessage {
-            from: system::SYSTEM_ACTOR_ADDR,
-            to: ACTIVITY_TRACKER_ACTOR_ADDR,
-            sequence: self.epoch as u64,
-            // exclude this from gas restriction
-            gas_limit: i64::MAX as u64,
-            method_num: fendermint_actor_activity_tracker::Method::BlockMined as u64,
-            params: fvm_ipld_encoding::RawBytes::serialize(params)?,
-            value: Default::default(),
-            version: Default::default(),
-            gas_fee_cap: Default::default(),
-            gas_premium: Default::default(),
-        };
-
-        self.apply_implicit_message(msg)?;
-        Ok(())
-    }
-
-    fn get_activities_summary(
-        &self,
-    ) -> anyhow::Result<ActivityDetails<Self::ValidatorSummaryDetail>> {
-        let msg = FvmMessage {
-            from: system::SYSTEM_ACTOR_ADDR,
-            to: ACTIVITY_TRACKER_ACTOR_ADDR,
-            sequence: self.epoch as u64,
-            // exclude this from gas restriction
-            gas_limit: i64::MAX as u64,
-            method_num: fendermint_actor_activity_tracker::Method::GetActivities as u64,
-            params: fvm_ipld_encoding::RawBytes::default(),
-            value: Default::default(),
-            version: Default::default(),
-            gas_fee_cap: Default::default(),
-            gas_premium: Default::default(),
-        };
-
-        let apply_ret = self.executor.call_state()?.call(msg)?;
-        let r = fvm_ipld_encoding::from_slice::<GetActivitiesResult>(
-            &apply_ret.msg_receipt.return_data,
-        )
-        .context("failed to parse validator activities")?;
-        Ok(ActivityDetails {
-            details: r.activities,
-        })
-    }
-
-    fn purge_activities(&mut self) -> anyhow::Result<()> {
-        let msg = FvmMessage {
-            from: system::SYSTEM_ACTOR_ADDR,
-            to: ACTIVITY_TRACKER_ACTOR_ADDR,
-            sequence: self.epoch as u64,
-            // exclude this from gas restriction
-            gas_limit: i64::MAX as u64,
-            method_num: fendermint_actor_activity_tracker::Method::PurgeActivities as u64,
-            params: fvm_ipld_encoding::RawBytes::default(),
-            value: Default::default(),
-            version: Default::default(),
-            gas_fee_cap: Default::default(),
-            gas_premium: Default::default(),
-        };
-
-        self.apply_implicit_message(msg)?;
-        Ok(())
-    }
-}
-
-impl<'a, DB: Blockstore + Clone + 'static> ActorActivityTracker<'a, DB> {
-    fn apply_implicit_message(&mut self, msg: FvmMessage) -> anyhow::Result<ApplyRet> {
-        let (apply_ret, _) = self.executor.execute_implicit(msg)?;
-        if let Some(err) = apply_ret.failure_info {
-            anyhow::bail!("failed to apply activity tracker messages: {}", err)
-        } else {
-            Ok(apply_ret)
-        }
-    }
-}
diff --git a/fendermint/vm/interpreter/src/fvm/activities/mod.rs b/fendermint/vm/interpreter/src/fvm/activities/mod.rs
deleted file mode 100644
index 1c509c2288..0000000000
--- a/fendermint/vm/interpreter/src/fvm/activities/mod.rs
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright 2022-2024 Protocol Labs
-// SPDX-License-Identifier: Apache-2.0, MIT
-
-//! Tracks the current blockchain block mining activities and propagates to the parent subnet if
-//! needed.
-
-pub mod actor;
-mod merkle;
-
-use crate::fvm::activities::merkle::MerkleProofGen;
-use fendermint_actor_activity_tracker::ValidatorSummary;
-use fendermint_crypto::PublicKey;
-use ipc_api::checkpoint::ActivitySummary;
-use std::fmt::Debug;
-
-pub struct BlockMined {
-    pub(crate) validator: PublicKey,
-}
-
-#[derive(Debug, Clone)]
-pub struct ActivityDetails<T> {
-    pub details: Vec<T>,
-}
-
-/// Tracks the validator activities in the current blockchain
-pub trait ValidatorActivityTracker {
-    type ValidatorSummaryDetail: Clone + Debug;
-
-    /// Mark the validator has mined the target block.
-    fn track_block_mined(&mut self, block: BlockMined) -> anyhow::Result<()>;
-
-    /// Get the validators activities summary since the checkpoint height
-    fn get_activities_summary(
-        &self,
-    ) -> anyhow::Result<ActivityDetails<Self::ValidatorSummaryDetail>>;
-
-    /// Purge the current validator activities summary
-    fn purge_activities(&mut self) -> anyhow::Result<()>;
-}
-
-impl ActivityDetails<ValidatorSummary> {
-    pub fn commitment(&self) -> anyhow::Result<ActivitySummary> {
-        let gen = MerkleProofGen::new(self.details.as_slice())?;
-        Ok(ActivitySummary {
-            total_active_validators: self.details.len() as u64,
-            commitment: gen.root().to_fixed_bytes().to_vec(),
-        })
-    }
-}
diff --git a/fendermint/vm/interpreter/src/fvm/activity/actor.rs b/fendermint/vm/interpreter/src/fvm/activity/actor.rs
new file mode 100644
index 0000000000..9948d0c531
--- /dev/null
+++ b/fendermint/vm/interpreter/src/fvm/activity/actor.rs
@@ -0,0 +1,75 @@
+// Copyright 2022-2024 Protocol Labs
+// SPDX-License-Identifier: Apache-2.0, MIT
+
+use crate::fvm::activity::{FullActivity, ValidatorActivityTracker};
+use crate::fvm::state::FvmExecState;
+use crate::fvm::FvmMessage;
+use anyhow::Context;
+use fendermint_actor_activity_tracker::types::FullActivityRollup;
+use fendermint_crypto::PublicKey;
+use fendermint_vm_actor_interface::activity::ACTIVITY_TRACKER_ACTOR_ADDR;
+use fendermint_vm_actor_interface::eam::EthAddress;
+use fendermint_vm_actor_interface::system;
+use fvm::executor::ApplyRet;
+use fvm_ipld_blockstore::Blockstore;
+use fvm_shared::address::Address;
+
+pub struct ActorActivityTracker<'a, DB: Blockstore + Clone + 'static> {
+    pub(crate) executor: &'a mut FvmExecState<DB>,
+}
+
+impl<'a, DB: Blockstore + Clone + 'static> ValidatorActivityTracker
+    for ActorActivityTracker<'a, DB>
+{
+    fn record_block_committed(&mut self, validator: PublicKey) -> anyhow::Result<()> {
+        let address: Address = EthAddress::from(validator).into();
+
+        let msg = FvmMessage {
+            from: system::SYSTEM_ACTOR_ADDR,
+            to: ACTIVITY_TRACKER_ACTOR_ADDR,
+            sequence: 0,                // irrelevant
+            gas_limit: i64::MAX as u64, // exclude this from gas restriction
+            method_num: fendermint_actor_activity_tracker::Method::RecordBlockCommitted as u64,
+            params: fvm_ipld_encoding::RawBytes::serialize(address)?,
+            value: Default::default(),
+            version: Default::default(),
+            gas_fee_cap: Default::default(),
+            gas_premium: Default::default(),
+        };
+
+        self.apply_implicit_message(msg)?;
+        Ok(())
+    }
+
+    fn commit_activity(&mut self) -> anyhow::Result<FullActivity> {
+        let msg = FvmMessage {
+            from: system::SYSTEM_ACTOR_ADDR,
+            to: ACTIVITY_TRACKER_ACTOR_ADDR,
+            sequence: 0,                // irrelevant
+            gas_limit: i64::MAX as u64, // exclude this from gas restriction
+            method_num: fendermint_actor_activity_tracker::Method::CommitActivity as u64,
+            params: fvm_ipld_encoding::RawBytes::default(),
+            value: Default::default(),
+            version: Default::default(),
+            gas_fee_cap: Default::default(),
+            gas_premium: Default::default(),
+        };
+
+        let (apply_ret, _) = self.executor.execute_implicit(msg)?;
+        let r =
+            fvm_ipld_encoding::from_slice::<FullActivityRollup>(&apply_ret.msg_receipt.return_data)
+                .context("failed to parse validator activities")?;
+        r.try_into()
+    }
+}
+
+impl<'a, DB: Blockstore + Clone + 'static> ActorActivityTracker<'a, DB> {
+    fn apply_implicit_message(&mut self, msg: FvmMessage) -> anyhow::Result<ApplyRet> {
+        let (apply_ret, _) = self.executor.execute_implicit(msg)?;
+        if let Some(err) = apply_ret.failure_info {
+            anyhow::bail!("failed to apply activity tracker messages: {}", err)
+        } else {
+            Ok(apply_ret)
+        }
+    }
+}
diff --git a/fendermint/vm/interpreter/src/fvm/activities/merkle.rs b/fendermint/vm/interpreter/src/fvm/activity/merkle.rs
similarity index 55%
rename from fendermint/vm/interpreter/src/fvm/activities/merkle.rs
rename to fendermint/vm/interpreter/src/fvm/activity/merkle.rs
index 53f2e7c3a4..7a7586bccb 100644
--- a/fendermint/vm/interpreter/src/fvm/activities/merkle.rs
+++ b/fendermint/vm/interpreter/src/fvm/activity/merkle.rs
@@ -2,8 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0, MIT
 
 use anyhow::Context;
-use fendermint_actor_activity_tracker::ValidatorSummary;
-use ipc_api::evm::payload_to_evm_address;
+use ipc_actors_abis::checkpointing_facet::ValidatorData;
 use ipc_observability::lazy_static;
 use merkle_tree_rs::format::Raw;
 use merkle_tree_rs::standard::StandardMerkleTree;
@@ -12,7 +11,7 @@ pub type Hash = ethers::types::H256;
 
 lazy_static!(
     /// ABI types of the Merkle tree which contains validator addresses and their voting power.
-    pub static ref VALIDATOR_SUMMARY_FIELDS: Vec<String> = vec!["address".to_owned(), "uint64".to_owned(), "bytes".to_owned()];
+    pub static ref VALIDATOR_SUMMARY_FIELDS: Vec<String> = vec!["address".to_owned(), "uint64".to_owned()];
 );
 
 /// The merkle tree based proof verification to interact with solidity contracts
@@ -21,25 +20,16 @@ pub(crate) struct MerkleProofGen {
 }
 
 impl MerkleProofGen {
+    pub fn pack_validator(v: &ValidatorData) -> Vec<String> {
+        vec![format!("{:?}", v.validator), v.blocks_committed.to_string()]
+    }
+
     pub fn root(&self) -> Hash {
         self.tree.root()
     }
-}
 
-impl MerkleProofGen {
-    pub fn new(values: &[ValidatorSummary]) -> anyhow::Result<Self> {
-        let values = values
-            .iter()
-            .map(|t| {
-                payload_to_evm_address(t.validator.payload()).map(|addr| {
-                    vec![
-                        format!("{addr:?}"),
-                        t.block_committed.to_string(),
-                        hex::encode(&t.metadata),
-                    ]
-                })
-            })
-            .collect::<anyhow::Result<Vec<_>>>()?;
+    pub fn new(values: &[ValidatorData]) -> anyhow::Result<Self> {
+        let values = values.iter().map(Self::pack_validator).collect::<Vec<_>>();
 
         let tree = StandardMerkleTree::of(&values, &VALIDATOR_SUMMARY_FIELDS)
             .context("failed to construct Merkle tree")?;
diff --git a/fendermint/vm/interpreter/src/fvm/activity/mod.rs b/fendermint/vm/interpreter/src/fvm/activity/mod.rs
new file mode 100644
index 0000000000..f44173aaf1
--- /dev/null
+++ b/fendermint/vm/interpreter/src/fvm/activity/mod.rs
@@ -0,0 +1,156 @@
+// Copyright 2022-2024 Protocol Labs
+// SPDX-License-Identifier: Apache-2.0, MIT
+
+//! Tracks the current blockchain block mining activities and propagates to the parent subnet if
+//! needed.
+
+pub mod actor;
+mod merkle;
+
+use crate::fvm::activity::merkle::MerkleProofGen;
+use fendermint_crypto::PublicKey;
+use ipc_actors_abis::checkpointing_facet::{
+    AggregatedStats, CompressedActivityRollup, CompressedSummary, FullActivityRollup, FullSummary,
+    ValidatorData,
+};
+use ipc_api::evm::payload_to_evm_address;
+
+/// Wrapper for FullActivityRollup with some utility functions
+pub struct FullActivity(FullActivityRollup);
+
+/// Tracks the validator activities in the current blockchain
+pub trait ValidatorActivityTracker {
+    /// Mark the validator has mined the target block.
+    fn record_block_committed(&mut self, validator: PublicKey) -> anyhow::Result<()>;
+
+    /// Get the validators activities summary since the checkpoint height
+    fn commit_activity(&mut self) -> anyhow::Result<FullActivity>;
+}
+
+impl TryFrom<fendermint_actor_activity_tracker::types::FullActivityRollup> for FullActivity {
+    type Error = anyhow::Error;
+
+    fn try_from(
+        value: fendermint_actor_activity_tracker::types::FullActivityRollup,
+    ) -> Result<Self, Self::Error> {
+        let f = FullActivityRollup {
+            consensus: FullSummary {
+                stats: AggregatedStats {
+                    total_active_validators: value.consensus.stats.total_active_validators,
+                    total_num_blocks_committed: value.consensus.stats.total_num_blocks_committed,
+                },
+                data: value
+                    .consensus
+                    .data
+                    .into_iter()
+                    .map(|(addr, data)| {
+                        Ok(ValidatorData {
+                            validator: payload_to_evm_address(addr.payload())?,
+                            blocks_committed: data.blocks_committed,
+                        })
+                    })
+                    .collect::<anyhow::Result<Vec<_>>>()?,
+            },
+        };
+        Ok(Self::new(f))
+    }
+}
+
+impl FullActivity {
+    pub fn new(mut full: FullActivityRollup) -> Self {
+        full.consensus.data.sort_by(|a, b| {
+            let cmp = a.validator.cmp(&b.validator);
+            if cmp.is_eq() {
+                // Address will be unique, do this just in case equal
+                a.blocks_committed.cmp(&b.blocks_committed)
+            } else {
+                cmp
+            }
+        });
+        Self(full)
+    }
+
+    pub fn compressed(&self) -> anyhow::Result<CompressedActivityRollup> {
+        let gen = MerkleProofGen::new(self.0.consensus.data.as_slice())?;
+        Ok(CompressedActivityRollup {
+            consensus: CompressedSummary {
+                stats: self.0.consensus.stats.clone(),
+                data_root_commitment: gen.root().to_fixed_bytes(),
+            },
+        })
+    }
+
+    pub fn into_inner(self) -> FullActivityRollup {
+        self.0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::fvm::activity::FullActivity;
+    use ipc_actors_abis::checkpointing_facet::{
+        AggregatedStats, FullActivityRollup, FullSummary, ValidatorData,
+    };
+    use rand::prelude::SliceRandom;
+    use rand::thread_rng;
+    use std::str::FromStr;
+
+    #[test]
+    fn test_commitment() {
+        let mut v = vec![
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0xB29C00299756135ec5d6A140CA54Ec77790a99d6",
+                )
+                .unwrap(),
+                blocks_committed: 1,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x28345a43c2fBae4412f0AbadFa06Bd8BA3f58867",
+                )
+                .unwrap(),
+                blocks_committed: 2,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x1A79385eAd0e873FE0C441C034636D3Edf7014cC",
+                )
+                .unwrap(),
+                blocks_committed: 10,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x76B9d5a35C46B1fFEb37aadf929f1CA63a26A829",
+                )
+                .unwrap(),
+                blocks_committed: 4,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x3c5cc76b07cb02a372e647887bD6780513659527",
+                )
+                .unwrap(),
+                blocks_committed: 3,
+            },
+        ];
+
+        for _ in 0..10 {
+            v.shuffle(&mut thread_rng());
+            let full = FullActivityRollup {
+                consensus: FullSummary {
+                    stats: AggregatedStats {
+                        total_active_validators: 1,
+                        total_num_blocks_committed: 2,
+                    },
+                    data: v.clone(),
+                },
+            };
+            let details = FullActivity::new(full);
+            assert_eq!(
+                hex::encode(details.compressed().unwrap().consensus.data_root_commitment),
+                "5519955f33109df3338490473cb14458640efdccd4df05998c4c439738280ab0"
+            );
+        }
+    }
+}
diff --git a/fendermint/vm/interpreter/src/fvm/checkpoint.rs b/fendermint/vm/interpreter/src/fvm/checkpoint.rs
index 4cb835c014..5aca2db831 100644
--- a/fendermint/vm/interpreter/src/fvm/checkpoint.rs
+++ b/fendermint/vm/interpreter/src/fvm/checkpoint.rs
@@ -1,42 +1,35 @@
 // Copyright 2022-2024 Protocol Labs
 // SPDX-License-Identifier: Apache-2.0, MIT
 
-use std::collections::HashMap;
-use std::time::Duration;
-
+use super::observe::{
+    CheckpointCreated, CheckpointFinalized, CheckpointSigned, CheckpointSignedRole,
+};
+use super::state::ipc::tokens_to_burn;
+use super::{
+    broadcast::Broadcaster,
+    state::{ipc::GatewayCaller, FvmExecState},
+    ValidatorContext,
+};
+use crate::fvm::activity::ValidatorActivityTracker;
+use crate::fvm::exec::BlockEndEvents;
 use anyhow::{anyhow, Context};
 use ethers::abi::Tokenizable;
-use tendermint::block::Height;
-use tendermint_rpc::endpoint::commit;
-use tendermint_rpc::{endpoint::validators, Client, Paging};
-
-use fvm_ipld_blockstore::Blockstore;
-use fvm_shared::{address::Address, chainid::ChainID};
-
 use fendermint_crypto::PublicKey;
 use fendermint_crypto::SecretKey;
 use fendermint_vm_actor_interface::eam::EthAddress;
 use fendermint_vm_actor_interface::ipc::BottomUpCheckpoint;
 use fendermint_vm_genesis::{Power, Validator, ValidatorKey};
-
-use ipc_api::evm::payload_to_evm_address;
-
+use fvm_ipld_blockstore::Blockstore;
+use fvm_shared::{address::Address, chainid::ChainID};
 use ipc_actors_abis::checkpointing_facet as checkpoint;
 use ipc_actors_abis::gateway_getter_facet as getter;
 use ipc_api::staking::ConfigurationNumber;
 use ipc_observability::{emit, serde::HexEncodableBlockHash};
-
-use super::observe::{
-    CheckpointCreated, CheckpointFinalized, CheckpointSigned, CheckpointSignedRole,
-};
-use super::state::ipc::tokens_to_burn;
-use super::{
-    broadcast::Broadcaster,
-    state::{ipc::GatewayCaller, FvmExecState},
-    ValidatorContext,
-};
-use crate::fvm::activities::ValidatorActivityTracker;
-use crate::fvm::exec::BlockEndEvents;
+use std::collections::HashMap;
+use std::time::Duration;
+use tendermint::block::Height;
+use tendermint_rpc::endpoint::commit;
+use tendermint_rpc::{endpoint::validators, Client, Paging};
 
 /// Validator voting power snapshot.
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -101,7 +94,7 @@ where
 
     let num_msgs = msgs.len();
 
-    let activities = state.activities_tracker().get_activities_summary()?;
+    let full_activity_rollup = state.activities_tracker().commit_activity()?;
 
     // Construct checkpoint.
     let checkpoint = BottomUpCheckpoint {
@@ -110,31 +103,21 @@ where
         block_hash,
         next_configuration_number,
         msgs,
-        activities: activities.commitment()?.try_into()?,
+        activities: full_activity_rollup.compressed()?,
     };
 
     // Save the checkpoint in the ledger.
     // Pass in the current power table, because these are the validators who can sign this checkpoint.
-    let report = checkpoint::ActivityReport {
-        validators: activities
-            .details
-            .into_iter()
-            .map(|v| {
-                Ok(checkpoint::ValidatorActivityReport {
-                    validator: payload_to_evm_address(v.validator.payload())?,
-                    blocks_committed: v.block_committed,
-                    metadata: ethers::types::Bytes::from(v.metadata),
-                })
-            })
-            .collect::<anyhow::Result<Vec<_>>>()?,
-    };
     let ret = gateway
-        .create_bu_ckpt_with_activities(state, checkpoint.clone(), &curr_power_table.0, report)
+        .create_bottom_up_checkpoint(
+            state,
+            checkpoint.clone(),
+            &curr_power_table.0,
+            full_activity_rollup.into_inner(),
+        )
         .context("failed to store checkpoint")?;
     event_tracker.push((ret.apply_ret.events, ret.emitters));
 
-    state.activities_tracker().purge_activities()?;
-
     // Figure out the power updates if there was some change in the configuration.
     let power_updates = if next_configuration_number == 0 {
         PowerUpdates(Vec::new())
@@ -266,9 +249,22 @@ where
                 block_hash: cp.block_hash,
                 next_configuration_number: cp.next_configuration_number,
                 msgs: convert_tokenizables(cp.msgs)?,
-                activities: checkpoint::ActivitySummary {
-                    total_active_validators: cp.activities.total_active_validators,
-                    commitment: cp.activities.commitment,
+                activities: checkpoint::CompressedActivityRollup {
+                    consensus: checkpoint::CompressedSummary {
+                        stats: checkpoint::AggregatedStats {
+                            total_active_validators: cp
+                                .activities
+                                .consensus
+                                .stats
+                                .total_active_validators,
+                            total_num_blocks_committed: cp
+                                .activities
+                                .consensus
+                                .stats
+                                .total_num_blocks_committed,
+                        },
+                        data_root_commitment: cp.activities.consensus.data_root_commitment,
+                    },
                 },
             };
 
diff --git a/fendermint/vm/interpreter/src/fvm/exec.rs b/fendermint/vm/interpreter/src/fvm/exec.rs
index 00814b4fa2..3006218a5e 100644
--- a/fendermint/vm/interpreter/src/fvm/exec.rs
+++ b/fendermint/vm/interpreter/src/fvm/exec.rs
@@ -7,7 +7,7 @@ use super::{
     state::FvmExecState,
     BlockGasLimit, FvmMessage, FvmMessageInterpreter,
 };
-use crate::fvm::activities::{BlockMined, ValidatorActivityTracker};
+use crate::fvm::activity::ValidatorActivityTracker;
 use crate::ExecInterpreter;
 use anyhow::Context;
 use async_trait::async_trait;
@@ -204,9 +204,7 @@ where
         let mut block_end_events = BlockEndEvents::default();
 
         if let Some(pubkey) = state.block_producer() {
-            state
-                .activities_tracker()
-                .track_block_mined(BlockMined { validator: pubkey })?;
+            state.activities_tracker().record_block_committed(pubkey)?;
         }
 
         let next_gas_market = state.finalize_gas_market()?;
diff --git a/fendermint/vm/interpreter/src/fvm/externs.rs b/fendermint/vm/interpreter/src/fvm/externs.rs
index 7f02b06118..f17e03f687 100644
--- a/fendermint/vm/interpreter/src/fvm/externs.rs
+++ b/fendermint/vm/interpreter/src/fvm/externs.rs
@@ -36,18 +36,6 @@ where
     }
 }
 
-impl<DB> FendermintExterns<DB>
-where
-    DB: Blockstore + 'static + Clone,
-{
-    pub fn read_only_clone(&self) -> FendermintExterns<ReadOnlyBlockstore<DB>> {
-        FendermintExterns {
-            blockstore: ReadOnlyBlockstore::new(self.blockstore.clone()),
-            state_root: self.state_root,
-        }
-    }
-}
-
 impl<DB> Rand for FendermintExterns<DB>
 where
     DB: Blockstore + 'static,
diff --git a/fendermint/vm/interpreter/src/fvm/mod.rs b/fendermint/vm/interpreter/src/fvm/mod.rs
index 2a4ce64329..85962ab4b2 100644
--- a/fendermint/vm/interpreter/src/fvm/mod.rs
+++ b/fendermint/vm/interpreter/src/fvm/mod.rs
@@ -15,7 +15,7 @@ pub mod upgrades;
 #[cfg(any(test, feature = "bundle"))]
 pub mod bundle;
 
-pub mod activities;
+pub mod activity;
 pub(crate) mod gas;
 pub(crate) mod topdown;
 
diff --git a/fendermint/vm/interpreter/src/fvm/state/exec.rs b/fendermint/vm/interpreter/src/fvm/state/exec.rs
index f26f634bf7..65b0a94386 100644
--- a/fendermint/vm/interpreter/src/fvm/state/exec.rs
+++ b/fendermint/vm/interpreter/src/fvm/state/exec.rs
@@ -1,13 +1,11 @@
 // Copyright 2022-2024 Protocol Labs
 // SPDX-License-Identifier: Apache-2.0, MIT
 
-use std::cell::RefCell;
 use std::collections::{HashMap, HashSet};
 
-use crate::fvm::activities::actor::ActorActivityTracker;
+use crate::fvm::activity::actor::ActorActivityTracker;
 use crate::fvm::externs::FendermintExterns;
 use crate::fvm::gas::BlockGasTracker;
-use crate::fvm::store::ReadOnlyBlockstore;
 use anyhow::Ok;
 use cid::Cid;
 use fendermint_actors_api::gas_market::Reading;
@@ -16,7 +14,6 @@ use fendermint_vm_actor_interface::eam::EthAddress;
 use fendermint_vm_core::{chainid::HasChainID, Timestamp};
 use fendermint_vm_encoding::IsHumanReadable;
 use fendermint_vm_genesis::PowerScale;
-use fvm::engine::EnginePool;
 use fvm::{
     call_manager::DefaultCallManager,
     engine::MultiEngine,
@@ -118,8 +115,6 @@ where
     params: FvmUpdatableParams,
     /// Indicate whether the parameters have been updated.
     params_dirty: bool,
-
-    executor_info: ExecutorInfo<DB>,
 }
 
 impl<DB> FvmExecState<DB>
@@ -169,11 +164,6 @@ where
                 power_scale: params.power_scale,
             },
             params_dirty: false,
-
-            executor_info: ExecutorInfo {
-                engine_pool: engine,
-                store: blockstore.clone(),
-            },
         })
     }
 
@@ -303,10 +293,7 @@ where
     }
 
     pub fn activities_tracker(&mut self) -> ActorActivityTracker<DB> {
-        ActorActivityTracker {
-            epoch: self.block_height(),
-            executor: self,
-        }
+        ActorActivityTracker { executor: self }
     }
 
     /// Collect all the event emitters' delegated addresses, for those who have any.
@@ -369,22 +356,6 @@ where
         f(&mut self.params);
         self.params_dirty = true;
     }
-
-    pub fn call_state(&self) -> anyhow::Result<FvmCallState<DB>> {
-        let externs = self.executor.externs().read_only_clone();
-        let machine = DefaultMachine::new(
-            self.executor.context(),
-            ReadOnlyBlockstore::new(self.executor_info.store.clone()),
-            externs,
-        )?;
-
-        Ok(FvmCallState {
-            executor: RefCell::new(DefaultExecutor::new(
-                self.executor_info.engine_pool.clone(),
-                machine,
-            )?),
-        })
-    }
 }
 
 impl<DB> HasChainID for FvmExecState<DB>
@@ -425,33 +396,3 @@ fn check_error(e: anyhow::Error) -> (ApplyRet, ActorAddressMap) {
     };
     (ret, Default::default())
 }
-
-/// Tracks the metadata about the executor, so that it can be used to clone itself or create call state
-struct ExecutorInfo<DB> {
-    engine_pool: EnginePool,
-    store: DB,
-}
-
-type CallExecutor<DB> = DefaultExecutor<
-    DefaultKernel<
-        DefaultCallManager<
-            DefaultMachine<ReadOnlyBlockstore<DB>, FendermintExterns<ReadOnlyBlockstore<DB>>>,
-        >,
-    >,
->;
-
-/// A state we create for the calling the getters through fvm
-pub struct FvmCallState<DB>
-where
-    DB: Blockstore + Clone + 'static,
-{
-    executor: RefCell<CallExecutor<DB>>,
-}
-
-impl<DB: Blockstore + Clone + 'static> FvmCallState<DB> {
-    pub fn call(&self, msg: Message) -> anyhow::Result<ApplyRet> {
-        let mut inner = self.executor.borrow_mut();
-        let raw_length = fvm_ipld_encoding::to_vec(&msg).map(|bz| bz.len())?;
-        Ok(inner.execute_message(msg, ApplyKind::Implicit, raw_length)?)
-    }
-}
diff --git a/fendermint/vm/interpreter/src/fvm/state/ipc.rs b/fendermint/vm/interpreter/src/fvm/state/ipc.rs
index 7fb7143dfb..2eb04c752c 100644
--- a/fendermint/vm/interpreter/src/fvm/state/ipc.rs
+++ b/fendermint/vm/interpreter/src/fvm/state/ipc.rs
@@ -123,28 +123,7 @@ impl<DB: Blockstore + Clone> GatewayCaller<DB> {
         state: &mut FvmExecState<DB>,
         checkpoint: checkpointing_facet::BottomUpCheckpoint,
         power_table: &[Validator<Power>],
-    ) -> anyhow::Result<()> {
-        // Construct a Merkle tree from the power table, which we can use to validate validator set membership
-        // when the signatures are submitted in transactions for accumulation.
-        let tree =
-            ValidatorMerkleTree::new(power_table).context("failed to create validator tree")?;
-
-        let total_power = power_table.iter().fold(et::U256::zero(), |p, v| {
-            p.saturating_add(et::U256::from(v.power.0))
-        });
-
-        self.checkpointing.call(state, |c| {
-            c.create_bottom_up_checkpoint(checkpoint, tree.root_hash().0, total_power)
-        })
-    }
-
-    /// Insert a new checkpoint at the period boundary.
-    pub fn create_bu_ckpt_with_activities(
-        &self,
-        state: &mut FvmExecState<DB>,
-        checkpoint: checkpointing_facet::BottomUpCheckpoint,
-        power_table: &[Validator<Power>],
-        activities: checkpointing_facet::ActivityReport,
+        activities: checkpointing_facet::FullActivityRollup,
     ) -> anyhow::Result<FvmApplyRet> {
         // Construct a Merkle tree from the power table, which we can use to validate validator set membership
         // when the signatures are submitted in transactions for accumulation.
diff --git a/fendermint/vm/message/Cargo.toml b/fendermint/vm/message/Cargo.toml
index 3816b9170b..77d264fb22 100644
--- a/fendermint/vm/message/Cargo.toml
+++ b/fendermint/vm/message/Cargo.toml
@@ -22,7 +22,7 @@ quickcheck = { workspace = true, optional = true }
 rand = { workspace = true, optional = true }
 
 cid = { workspace = true }
-fvm_shared = { workspace = true }
+fvm_shared = { workspace = true, features  = ["crypto"] }
 fvm_ipld_encoding = { workspace = true }
 ipc-api = { workspace = true }
 
diff --git a/ipc/api/src/checkpoint.rs b/ipc/api/src/checkpoint.rs
index 5edb1a7d89..e19691454d 100644
--- a/ipc/api/src/checkpoint.rs
+++ b/ipc/api/src/checkpoint.rs
@@ -76,40 +76,52 @@ pub struct BottomUpMsgBatch {
     pub msgs: Vec<IpcEnvelope>,
 }
 
-/// The commitments for the child subnet activities that should be submitted to the parent subnet
-/// together with a bottom up checkpoint
+/// Compressed representation of the activity summary that can be embedded in checkpoints to propagate up the hierarchy.
 #[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
-pub struct ValidatorSummary {
-    /// The checkpoint height in the child subnet
-    pub checkpoint_height: u64,
-    /// The validator address
-    pub validator: Address,
-    /// The number of blocks mined
-    pub blocks_committed: u64,
-    /// The extra metadata attached to the validator
-    pub metadata: Vec<u8>,
+pub struct CompressedActivityRollup {
+    pub consensus: consensus::CompressedSummary,
 }
 
-#[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
-pub struct BatchClaimProofs {
-    pub subnet_id: SubnetID,
-    pub proofs: Vec<ValidatorClaimProof>,
-}
+/// Namespace for consensus-level activity summaries.
+/// XYZ(raulk) move to activity module
+pub mod consensus {
+    use fvm_shared::address::Address;
+    use serde::{Deserialize, Serialize};
 
-#[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
-pub struct ValidatorClaimProof {
-    pub summary: ValidatorSummary,
-    pub proof: Vec<[u8; 32]>,
-}
+    /// Aggregated stats for consensus-level activity.
+    #[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
+    pub struct AggregatedStats {
+        /// The total number of unique validators that have mined within this period.
+        pub total_active_validators: u64,
+        /// The total number of blocks committed by all validators during this period.
+        pub total_num_blocks_committed: u64,
+    }
 
-#[serde_as]
-#[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
-pub struct ActivitySummary {
-    pub total_active_validators: u64,
-    /// The activity summary for validators
-    #[serde_as(as = "HumanReadable")]
-    pub commitment: Vec<u8>,
-    // TODO: add relayed activity commitment
+    /// The commitments for the child subnet activities that should be submitted to the parent subnet
+    /// together with a bottom up checkpoint
+    #[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
+    pub struct ValidatorData {
+        /// The validator address
+        pub validator: Address,
+        /// The number of blocks mined
+        pub blocks_committed: u64,
+    }
+
+    // The full activity summary for consensus-level activity.
+    #[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
+    pub struct FullSummary {
+        pub stats: AggregatedStats,
+        /// The breakdown of activity per validator.
+        pub data: Vec<ValidatorData>,
+    }
+
+    /// The compresed representation of the activity summary for consensus-level activity suitable for embedding in a checkpoint.
+    #[derive(PartialEq, Eq, Clone, Debug, Serialize, Deserialize)]
+    pub struct CompressedSummary {
+        pub stats: AggregatedStats,
+        /// The commitment for the validator details, so that we don't have to transmit them in full.
+        pub data_root_commitment: Vec<u8>,
+    }
 }
 
 #[serde_as]
@@ -131,7 +143,7 @@ pub struct BottomUpCheckpoint {
     /// The list of messages for execution
     pub msgs: Vec<IpcEnvelope>,
     /// The activity commitment from child subnet to parent subnet
-    pub activities: ActivitySummary,
+    pub activity_rollup: CompressedActivityRollup,
 }
 
 pub fn serialize_vec_bytes_to_vec_hex<T: AsRef<[u8]>, S>(
diff --git a/ipc/api/src/evm.rs b/ipc/api/src/evm.rs
index 7722a19d05..dd40829eaa 100644
--- a/ipc/api/src/evm.rs
+++ b/ipc/api/src/evm.rs
@@ -4,8 +4,8 @@
 //! Type conversion for IPC Agent struct with solidity contract struct
 
 use crate::address::IPCAddress;
-use crate::checkpoint::{ActivitySummary, BatchClaimProofs, BottomUpCheckpoint};
-use crate::checkpoint::{BottomUpMsgBatch, ValidatorClaimProof};
+use crate::checkpoint::BottomUpMsgBatch;
+use crate::checkpoint::{consensus, BottomUpCheckpoint, CompressedActivityRollup};
 use crate::cross::{IpcEnvelope, IpcMsgKind};
 use crate::staking::StakingChange;
 use crate::staking::StakingChangeRequest;
@@ -122,14 +122,55 @@ macro_rules! cross_msg_types {
 /// The type conversion between different bottom up checkpoint definition in ethers and sdk
 macro_rules! bottom_up_checkpoint_conversion {
     ($module:ident) => {
-        impl TryFrom<ActivitySummary> for $module::ActivitySummary {
+        impl TryFrom<consensus::AggregatedStats> for $module::AggregatedStats {
             type Error = anyhow::Error;
 
-            fn try_from(c: ActivitySummary) -> Result<Self, Self::Error> {
-                Ok($module::ActivitySummary {
+            fn try_from(c: consensus::AggregatedStats) -> Result<Self, Self::Error> {
+                Ok($module::AggregatedStats {
                     total_active_validators: c.total_active_validators,
-                    commitment: c
-                        .commitment
+                    total_num_blocks_committed: c.total_num_blocks_committed,
+                })
+            }
+        }
+
+        impl TryFrom<CompressedActivityRollup> for $module::CompressedActivityRollup {
+            type Error = anyhow::Error;
+
+            fn try_from(c: CompressedActivityRollup) -> Result<Self, Self::Error> {
+                Ok($module::CompressedActivityRollup {
+                    consensus: c.consensus.try_into()?,
+                })
+            }
+        }
+
+        impl From<$module::CompressedActivityRollup> for CompressedActivityRollup {
+            fn from(value: $module::CompressedActivityRollup) -> Self {
+                CompressedActivityRollup {
+                    consensus: consensus::CompressedSummary {
+                        stats: consensus::AggregatedStats {
+                            total_active_validators: value.consensus.stats.total_active_validators,
+                            total_num_blocks_committed: value
+                                .consensus
+                                .stats
+                                .total_num_blocks_committed,
+                        },
+                        data_root_commitment: value.consensus.data_root_commitment.to_vec(),
+                    },
+                }
+            }
+        }
+
+        impl TryFrom<consensus::CompressedSummary> for $module::CompressedSummary {
+            type Error = anyhow::Error;
+
+            fn try_from(c: consensus::CompressedSummary) -> Result<Self, Self::Error> {
+                Ok($module::CompressedSummary {
+                    stats: c
+                        .stats
+                        .try_into()
+                        .map_err(|_| anyhow!("cannot convert aggregated stats"))?,
+                    data_root_commitment: c
+                        .data_root_commitment
                         .try_into()
                         .map_err(|_| anyhow!("cannot convert bytes32"))?,
                 })
@@ -150,7 +191,7 @@ macro_rules! bottom_up_checkpoint_conversion {
                         .into_iter()
                         .map($module::IpcEnvelope::try_from)
                         .collect::<Result<Vec<_>, _>>()?,
-                    activities: checkpoint.activities.try_into()?,
+                    activities: checkpoint.activity_rollup.try_into()?,
                 })
             }
         }
@@ -169,10 +210,7 @@ macro_rules! bottom_up_checkpoint_conversion {
                         .into_iter()
                         .map(IpcEnvelope::try_from)
                         .collect::<Result<Vec<_>, _>>()?,
-                    activities: ActivitySummary {
-                        total_active_validators: value.activities.total_active_validators,
-                        commitment: value.activities.commitment.to_vec(),
-                    },
+                    activity_rollup: value.activities.into(),
                 })
             }
         }
@@ -277,22 +315,6 @@ impl TryFrom<u8> for AssetKind {
     }
 }
 
-impl TryFrom<ValidatorClaimProof> for validator_reward_facet::ValidatorClaimProof {
-    type Error = anyhow::Error;
-
-    fn try_from(v: ValidatorClaimProof) -> Result<Self, Self::Error> {
-        Ok(Self {
-            proof: v.proof,
-            summary: validator_reward_facet::ValidatorSummary {
-                checkpoint_height: v.summary.checkpoint_height,
-                validator: payload_to_evm_address(v.summary.validator.payload())?,
-                blocks_committed: v.summary.blocks_committed,
-                metadata: ethers::types::Bytes::from(v.summary.metadata),
-            },
-        })
-    }
-}
-
 /// Convert the ipc SubnetID type to a vec of evm addresses. It extracts all the children addresses
 /// in the subnet id and turns them as a vec of evm addresses.
 pub fn subnet_id_to_evm_addresses(
@@ -322,21 +344,6 @@ pub fn fil_to_eth_amount(amount: &TokenAmount) -> anyhow::Result<U256> {
     Ok(U256::from_dec_str(&str)?)
 }
 
-impl TryFrom<BatchClaimProofs> for validator_reward_facet::BatchClaimProofs {
-    type Error = anyhow::Error;
-
-    fn try_from(v: BatchClaimProofs) -> Result<Self, Self::Error> {
-        Ok(Self {
-            subnet_id: validator_reward_facet::SubnetID::try_from(&v.subnet_id)?,
-            proofs: v
-                .proofs
-                .into_iter()
-                .map(validator_reward_facet::ValidatorClaimProof::try_from)
-                .collect::<Result<Vec<_>, _>>()?,
-        })
-    }
-}
-
 impl TryFrom<StakingChange> for top_down_finality_facet::StakingChange {
     type Error = anyhow::Error;
 
diff --git a/ipc/cli/src/commands/validator/batch_claim.rs b/ipc/cli/src/commands/validator/batch_claim.rs
index 6cdb106bac..efc0522fa4 100644
--- a/ipc/cli/src/commands/validator/batch_claim.rs
+++ b/ipc/cli/src/commands/validator/batch_claim.rs
@@ -18,11 +18,8 @@ pub(crate) struct BatchClaimArgs {
     pub from: ChainEpoch,
     #[arg(long, help = "The checkpoint height to claim to")]
     pub to: ChainEpoch,
-    #[arg(
-        long,
-        help = "The source subnets that generated the reward, use ',' to separate subnets"
-    )]
-    pub reward_source_subnets: String,
+    #[arg(long, help = "The source subnet that generated the reward")]
+    pub reward_source_subnet: String,
     #[arg(long, help = "The subnet to claim reward from")]
     pub reward_claim_subnet: String,
 }
@@ -38,18 +35,14 @@ impl CommandLineHandler for BatchClaim {
 
         let provider = get_ipc_provider(global)?;
 
-        let reward_source_subnets = arguments
-            .reward_source_subnets
-            .split(',')
-            .map(SubnetID::from_str)
-            .collect::<Result<Vec<_>, _>>()?;
+        let reward_source_subnet = SubnetID::from_str(&arguments.reward_source_subnet)?;
         let reward_claim_subnet = SubnetID::from_str(&arguments.reward_claim_subnet)?;
         let validator = Address::from_str(&arguments.validator)?;
 
         provider
-            .batch_claim(
+            .batch_subnet_claim(
                 &reward_claim_subnet,
-                &reward_source_subnets,
+                &reward_source_subnet,
                 arguments.from,
                 arguments.to,
                 &validator,
diff --git a/ipc/cli/src/commands/validator/list.rs b/ipc/cli/src/commands/validator/list.rs
index 7209de34d1..f3b666e76c 100644
--- a/ipc/cli/src/commands/validator/list.rs
+++ b/ipc/cli/src/commands/validator/list.rs
@@ -40,10 +40,9 @@ impl CommandLineHandler for ListActivities {
             .await?;
 
         println!("found total {} entries", r.len());
-        for v in r {
-            println!("checkpoint height: {}", v.checkpoint_height);
+        for (checkpoint_height, v) in r {
+            println!("  checkpoint height: {}", checkpoint_height);
             println!("  addr: {}", v.validator);
-            println!("  metadata: {}", hex::encode(v.metadata));
             println!("  locks_committed: {}", v.blocks_committed);
         }
 
diff --git a/ipc/provider/Cargo.toml b/ipc/provider/Cargo.toml
index 758f1306d9..4a9c7bbe93 100644
--- a/ipc/provider/Cargo.toml
+++ b/ipc/provider/Cargo.toml
@@ -42,7 +42,7 @@ zeroize = { workspace = true }
 
 fil_actors_runtime = { workspace = true }
 fvm_ipld_encoding = { workspace = true }
-fvm_shared = { workspace = true }
+fvm_shared = { workspace = true, features  = ["crypto"] }
 
 merkle-tree-rs = { path = "../../ext/merkle-tree-rs" }
 
diff --git a/ipc/provider/src/lib.rs b/ipc/provider/src/lib.rs
index f6c7cb27cb..aad51e6b4a 100644
--- a/ipc/provider/src/lib.rs
+++ b/ipc/provider/src/lib.rs
@@ -9,9 +9,8 @@ use config::Config;
 use fvm_shared::{
     address::Address, clock::ChainEpoch, crypto::signature::SignatureType, econ::TokenAmount,
 };
-use ipc_api::checkpoint::{
-    BatchClaimProofs, BottomUpCheckpointBundle, QuorumReachedEvent, ValidatorSummary,
-};
+use ipc_api::checkpoint::consensus::ValidatorData;
+use ipc_api::checkpoint::{BottomUpCheckpointBundle, QuorumReachedEvent};
 use ipc_api::evm::payload_to_evm_address;
 use ipc_api::staking::{StakingChangeRequest, ValidatorInfo};
 use ipc_api::subnet::{Asset, PermissionMode};
@@ -754,48 +753,34 @@ impl IpcProvider {
         validator: &Address,
         from: ChainEpoch,
         to: ChainEpoch,
-    ) -> anyhow::Result<Vec<ValidatorSummary>> {
+    ) -> anyhow::Result<Vec<(u64, ValidatorData)>> {
         let conn = self.get_connection(subnet)?;
         conn.manager()
-            .get_validator_activities(validator, from, to)
+            .query_validator_rewards(validator, from, to)
             .await
     }
 
-    pub async fn batch_claim(
+    pub async fn batch_subnet_claim(
         &self,
         reward_claim_subnet: &SubnetID,
-        reward_source_subnets: &[SubnetID],
+        reward_source_subnet: &SubnetID, // TODO(review): eventually support multiple source subnets
         from: ChainEpoch,
         to: ChainEpoch,
         validator: &Address,
     ) -> anyhow::Result<()> {
-        let mut batch_proofs = vec![];
-        for source_subnet in reward_source_subnets {
-            let conn = self.get_connection(source_subnet)?;
-
-            let proofs = conn
-                .manager()
-                .get_validator_claim_proofs(validator, from, to)
-                .await?;
-            if proofs.is_empty() {
-                return Err(anyhow!(
-                    "address {} has no reward to claim",
-                    validator.to_string()
-                ));
-            }
+        let conn = self.get_connection(reward_source_subnet)?;
 
-            batch_proofs.push(BatchClaimProofs {
-                subnet_id: source_subnet.clone(),
-                proofs,
-            });
-        }
+        let claims = conn
+            .manager()
+            .query_reward_claims(validator, from, to)
+            .await?;
 
         let parent = reward_claim_subnet
             .parent()
             .ok_or_else(|| anyhow!("no parent found"))?;
         let conn = self.get_connection(&parent)?;
         conn.manager()
-            .batch_claim(validator, reward_claim_subnet, batch_proofs)
+            .batch_subnet_claim(validator, reward_claim_subnet, reward_source_subnet, claims)
             .await
     }
 }
diff --git a/ipc/provider/src/manager/evm/manager.rs b/ipc/provider/src/manager/evm/manager.rs
index 503cdfbfa6..43d68971a5 100644
--- a/ipc/provider/src/manager/evm/manager.rs
+++ b/ipc/provider/src/manager/evm/manager.rs
@@ -36,15 +36,17 @@ use ethers::abi::Tokenizable;
 use ethers::contract::abigen;
 use ethers::prelude::k256::ecdsa::SigningKey;
 use ethers::prelude::{Signer, SignerMiddleware};
-use ethers::providers::{Authorization, Http, Middleware, Provider};
+use ethers::providers::{Authorization, Http, Provider};
 use ethers::signers::{LocalWallet, Wallet};
-use ethers::types::{BlockId, Eip1559TransactionRequest, ValueOrArray, I256, U256};
+use ethers::types::{BlockId, Eip1559TransactionRequest, ValueOrArray, H256, I256, U256};
 
+use ethers::middleware::Middleware;
 use fvm_shared::clock::ChainEpoch;
 use fvm_shared::{address::Address, econ::TokenAmount};
+use ipc_actors_abis::validator_reward_facet::ValidatorClaim;
 use ipc_api::checkpoint::{
-    BatchClaimProofs, BottomUpCheckpoint, BottomUpCheckpointBundle, QuorumReachedEvent, Signature,
-    ValidatorClaimProof, ValidatorSummary,
+    consensus::ValidatorData, BottomUpCheckpoint, BottomUpCheckpointBundle, QuorumReachedEvent,
+    Signature,
 };
 use ipc_api::cross::IpcEnvelope;
 use ipc_api::staking::{StakingChangeRequest, ValidatorInfo, ValidatorStakingInfo};
@@ -1284,124 +1286,128 @@ impl BottomUpCheckpointRelayer for EthSubnetManager {
 }
 
 lazy_static!(
-    /// ABI types of the Merkle tree which contains validator addresses and their voting power.
-    pub static ref VALIDATOR_SUMMARY_FIELDS: Vec<String> = vec!["address".to_owned(), "uint64".to_owned(), "bytes".to_owned()];
+    /// ABI types of the Merkle tree which contains validator addresses and their committed block count.
+    pub static ref VALIDATOR_SUMMARY_FIELDS: Vec<String> = vec!["address".to_owned(), "uint64".to_owned()];
 );
 
 #[async_trait]
 impl ValidatorRewarder for EthSubnetManager {
-    async fn get_validator_claim_proofs(
+    /// Query validator claims, indexed by checkpoint height, to batch claim rewards.
+    async fn query_reward_claims(
         &self,
         validator_addr: &Address,
         from_checkpoint: ChainEpoch,
         to_checkpoint: ChainEpoch,
-    ) -> Result<Vec<ValidatorClaimProof>> {
+    ) -> Result<Vec<(u64, ValidatorClaim)>> {
         let contract = checkpointing_facet::CheckpointingFacet::new(
             self.ipc_contract_info.gateway_addr,
             Arc::new(self.ipc_contract_info.provider.clone()),
         );
 
         let ev = contract
-            .event::<checkpointing_facet::ActivityReportCreatedFilter>()
+            .event::<checkpointing_facet::ActivityRollupRecordedFilter>()
             .from_block(from_checkpoint as u64)
             .to_block(to_checkpoint as u64)
             .address(ValueOrArray::Value(contract.address()));
 
-        let validator_evm_addr = payload_to_evm_address(validator_addr.payload())?;
+        let validator_eth_addr = payload_to_evm_address(validator_addr.payload())?;
 
-        let mut proofs = vec![];
+        let mut claims = vec![];
         for (event, meta) in query_with_meta(ev, contract.client()).await? {
-            tracing::debug!("found event at height: {}", meta.block_number);
-
-            let mut activities = vec![];
-            let mut maybe_validator = None;
-            for validator in event.report.validators {
-                let payload = vec![
-                    format!("{:?}", validator.validator),
-                    validator.blocks_committed.to_string(),
-                    hex::encode(validator.metadata.as_ref()),
-                ];
-
-                if validator.validator == validator_evm_addr {
-                    let summary = ValidatorSummary {
-                        checkpoint_height: event.checkpoint_height,
-                        validator: *validator_addr,
-                        blocks_committed: validator.blocks_committed,
-                        metadata: validator.metadata.to_vec(),
-                    };
-                    maybe_validator = Some((payload.clone(), summary));
-                }
-
-                activities.push(payload);
-            }
-
-            let tree = StandardMerkleTree::<Raw>::of(&activities, &VALIDATOR_SUMMARY_FIELDS)
-                .context("failed to construct Merkle tree")?;
-
-            let Some((payload, summary)) = maybe_validator else {
+            tracing::debug!(
+                "found activity bundle published at height: {}",
+                meta.block_number
+            );
+
+            // Check if we have claims for this validator in this block.
+            let our_data = event
+                .rollup
+                .consensus
+                .data
+                .iter()
+                .find(|v| v.validator == validator_eth_addr);
+
+            // If we don't, skip this block.
+            let Some(data) = our_data else {
                 tracing::info!(
-                    "target validator address has not activities in epoch {}",
+                    "target validator address has no reward claims in epoch {}",
                     meta.block_number
                 );
                 continue;
             };
-            let proof = tree.get_proof(LeafType::LeafBytes(payload))?;
 
-            proofs.push(ValidatorClaimProof {
-                summary,
+            let proof = gen_merkle_proof(&event.rollup.consensus.data, data)?;
+
+            // Construct the claim and add it to the list.
+            let claim = ValidatorClaim {
+                // Even though it's the same struct but still need to do a mapping due to
+                // different crate from ethers-rs
+                data: validator_reward_facet::ValidatorData {
+                    validator: data.validator,
+                    blocks_committed: data.blocks_committed,
+                },
                 proof: proof.into_iter().map(|v| v.into()).collect(),
-            });
+            };
+            claims.push((event.checkpoint_height, claim));
         }
 
-        Ok(proofs)
+        Ok(claims)
     }
 
-    /// Get the reward for specific validator in a subnet
-    async fn get_validator_activities(
+    /// Query validator rewards in the current subnet, without obtaining proofs.
+    async fn query_validator_rewards(
         &self,
         validator_addr: &Address,
         from_checkpoint: ChainEpoch,
         to_checkpoint: ChainEpoch,
-    ) -> Result<Vec<ValidatorSummary>> {
+    ) -> Result<Vec<(u64, ValidatorData)>> {
         let contract = checkpointing_facet::CheckpointingFacet::new(
             self.ipc_contract_info.gateway_addr,
             Arc::new(self.ipc_contract_info.provider.clone()),
         );
 
         let ev = contract
-            .event::<checkpointing_facet::ActivityReportCreatedFilter>()
+            .event::<checkpointing_facet::ActivityRollupRecordedFilter>()
             .from_block(from_checkpoint as u64)
             .to_block(to_checkpoint as u64)
             .address(ValueOrArray::Value(contract.address()));
 
-        let mut activities = vec![];
+        let mut rewards = vec![];
         let validator_eth_addr = payload_to_evm_address(validator_addr.payload())?;
 
         for (event, meta) in query_with_meta(ev, contract.client()).await? {
-            tracing::debug!("found event at height: {}", meta.block_number);
-            for validator in event.report.validators {
-                if validator.validator != validator_eth_addr {
-                    continue;
-                }
-
-                activities.push(ValidatorSummary {
+            tracing::debug!(
+                "found activity bundle published at height: {}",
+                meta.block_number
+            );
+
+            // Check if we have rewards for this validator in this block.
+            if let Some(data) = event
+                .rollup
+                .consensus
+                .data
+                .iter()
+                .find(|v| v.validator == validator_eth_addr)
+            {
+                // TODO type conversion.
+                let data = ValidatorData {
                     validator: *validator_addr,
-                    checkpoint_height: event.checkpoint_height,
-                    blocks_committed: validator.blocks_committed,
-                    metadata: validator.metadata.to_vec(),
-                });
+                    blocks_committed: data.blocks_committed,
+                };
+                rewards.push((meta.block_number.as_u64(), data));
             }
         }
 
-        Ok(activities)
+        Ok(rewards)
     }
 
-    /// Claim the reward in batch
-    async fn batch_claim(
+    /// Claim validator rewards in a batch for the specified subnet.
+    async fn batch_subnet_claim(
         &self,
         submitter: &Address,
         reward_claim_subnet: &SubnetID,
-        payloads: Vec<BatchClaimProofs>,
+        reward_origin_subnet: &SubnetID,
+        claims: Vec<(u64, ValidatorClaim)>,
     ) -> Result<()> {
         let signer = Arc::new(self.get_signer(submitter)?);
         let contract = validator_reward_facet::ValidatorRewardFacet::new(
@@ -1409,12 +1415,14 @@ impl ValidatorRewarder for EthSubnetManager {
             signer.clone(),
         );
 
-        let p = payloads
-            .into_iter()
-            .map(validator_reward_facet::BatchClaimProofs::try_from)
-            .collect::<Result<Vec<_>>>()?;
-        let call = contract.batch_claim(p);
-        let call = call_with_premium_and_pending_block(signer, call).await?;
+        // separate the Vec of tuples claims into two Vecs of Height and Claim
+        let (heights, claims): (Vec<u64>, Vec<ValidatorClaim>) = claims.into_iter().unzip();
+
+        let call = {
+            let call =
+                contract.batch_subnet_claim(reward_origin_subnet.try_into()?, heights, claims);
+            call_with_premium_and_pending_block(signer, call).await?
+        };
 
         call.send().await?;
 
@@ -1422,6 +1430,63 @@ impl ValidatorRewarder for EthSubnetManager {
     }
 }
 
+fn gen_merkle_proof(
+    validator_data: &[checkpointing_facet::ValidatorData],
+    validator: &checkpointing_facet::ValidatorData,
+) -> anyhow::Result<Vec<H256>> {
+    // Utilty function to pack validator data into a vector of strings for proof generation.
+    let pack_validator_data = |v: &checkpointing_facet::ValidatorData| {
+        vec![format!("{:?}", v.validator), v.blocks_committed.to_string()]
+    };
+
+    let tree = gen_merkle_tree(validator_data, pack_validator_data)?;
+
+    let leaf = pack_validator_data(validator);
+    tree.get_proof(LeafType::LeafBytes(leaf))
+}
+
+fn gen_merkle_tree<F: Fn(&checkpointing_facet::ValidatorData) -> Vec<String>>(
+    validator_data: &[checkpointing_facet::ValidatorData],
+    pack_validator_data: F,
+) -> anyhow::Result<StandardMerkleTree<Raw>> {
+    let leaves = order_validator_data(validator_data)?
+        .iter()
+        .map(pack_validator_data)
+        .collect::<Vec<_>>();
+    StandardMerkleTree::<Raw>::of(&leaves, &VALIDATOR_SUMMARY_FIELDS)
+        .context("failed to construct Merkle tree")
+}
+
+fn order_validator_data(
+    validator_data: &[checkpointing_facet::ValidatorData],
+) -> anyhow::Result<Vec<checkpointing_facet::ValidatorData>> {
+    let mut mapped = validator_data
+        .iter()
+        .map(|a| ethers_address_to_fil_address(&a.validator).map(|v| (v, a.blocks_committed)))
+        .collect::<Result<Vec<_>, _>>()?;
+
+    mapped.sort_by(|a, b| {
+        let cmp = a.0.cmp(&b.0);
+        if cmp.is_eq() {
+            // Address will be unique, do this just in case equal
+            a.1.cmp(&b.1)
+        } else {
+            cmp
+        }
+    });
+
+    let back_to_eth = |(fvm_addr, blocks): (Address, u64)| {
+        payload_to_evm_address(fvm_addr.payload()).map(|v| checkpointing_facet::ValidatorData {
+            validator: v,
+            blocks_committed: blocks,
+        })
+    };
+    mapped
+        .into_iter()
+        .map(back_to_eth)
+        .collect::<Result<Vec<_>, _>>()
+}
+
 /// Takes a `FunctionCall` input and returns a new instance with an estimated optimal `gas_premium`.
 /// The function also uses the pending block number to help retrieve the latest nonce
 /// via `get_transaction_count` with the `pending` parameter.
@@ -1648,8 +1713,11 @@ impl TryFrom<gateway_getter_facet::Subnet> for SubnetInfo {
 
 #[cfg(test)]
 mod tests {
-    use crate::manager::evm::manager::contract_address_from_subnet;
+    use crate::manager::evm::manager::{contract_address_from_subnet, gen_merkle_tree};
+    use ethers::core::rand::prelude::SliceRandom;
+    use ethers::core::rand::{random, thread_rng};
     use fvm_shared::address::Address;
+    use ipc_actors_abis::checkpointing_facet::{checkpointing_facet, ValidatorData};
     use ipc_api::subnet_id::SubnetID;
     use std::str::FromStr;
 
@@ -1664,4 +1732,91 @@ mod tests {
             "0x2e714a3c385ea88a09998ed74db265dae9853667"
         );
     }
+
+    /// test case that makes sure the commitment created for various addresses and blocks committed
+    /// are consistent
+    #[test]
+    fn test_validator_rewarder_claim_commitment() {
+        let pack_validator_data = |v: &checkpointing_facet::ValidatorData| {
+            vec![format!("{:?}", v.validator), v.blocks_committed.to_string()]
+        };
+
+        let mut random_validator_data = vec![
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0xB29C00299756135ec5d6A140CA54Ec77790a99d6",
+                )
+                .unwrap(),
+                blocks_committed: 1,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x1A79385eAd0e873FE0C441C034636D3Edf7014cC",
+                )
+                .unwrap(),
+                blocks_committed: 10,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x28345a43c2fBae4412f0AbadFa06Bd8BA3f58867",
+                )
+                .unwrap(),
+                blocks_committed: 2,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x3c5cc76b07cb02a372e647887bD6780513659527",
+                )
+                .unwrap(),
+                blocks_committed: 3,
+            },
+            ValidatorData {
+                validator: ethers::types::Address::from_str(
+                    "0x76B9d5a35C46B1fFEb37aadf929f1CA63a26A829",
+                )
+                .unwrap(),
+                blocks_committed: 4,
+            },
+        ];
+        random_validator_data.shuffle(&mut thread_rng());
+
+        let root = gen_merkle_tree(&random_validator_data, pack_validator_data)
+            .unwrap()
+            .root();
+        assert_eq!(
+            hex::encode(root.0),
+            "5519955f33109df3338490473cb14458640efdccd4df05998c4c439738280ab0"
+        );
+    }
+
+    #[test]
+    fn test_validator_rewarder_claim_commitment_ii() {
+        let pack_validator_data = |v: &checkpointing_facet::ValidatorData| {
+            vec![format!("{:?}", v.validator), v.blocks_committed.to_string()]
+        };
+
+        let mut random_validator_data = (0..100)
+            .map(|_| ValidatorData {
+                validator: ethers::types::Address::random(),
+                blocks_committed: random::<u64>(),
+            })
+            .collect::<Vec<_>>();
+
+        random_validator_data.shuffle(&mut thread_rng());
+        let root = gen_merkle_tree(&random_validator_data, pack_validator_data)
+            .unwrap()
+            .root();
+
+        random_validator_data.shuffle(&mut thread_rng());
+        let new_root = gen_merkle_tree(&random_validator_data, pack_validator_data)
+            .unwrap()
+            .root();
+        assert_eq!(new_root, root);
+
+        random_validator_data.shuffle(&mut thread_rng());
+        let new_root = gen_merkle_tree(&random_validator_data, pack_validator_data)
+            .unwrap()
+            .root();
+        assert_eq!(new_root, root);
+    }
 }
diff --git a/ipc/provider/src/manager/subnet.rs b/ipc/provider/src/manager/subnet.rs
index 62cbf983b1..a520959492 100644
--- a/ipc/provider/src/manager/subnet.rs
+++ b/ipc/provider/src/manager/subnet.rs
@@ -7,9 +7,10 @@ use anyhow::Result;
 use async_trait::async_trait;
 use fvm_shared::clock::ChainEpoch;
 use fvm_shared::{address::Address, econ::TokenAmount};
+use ipc_actors_abis::validator_reward_facet::ValidatorClaim;
 use ipc_api::checkpoint::{
-    BatchClaimProofs, BottomUpCheckpoint, BottomUpCheckpointBundle, QuorumReachedEvent, Signature,
-    ValidatorClaimProof, ValidatorSummary,
+    consensus::ValidatorData, BottomUpCheckpoint, BottomUpCheckpointBundle, QuorumReachedEvent,
+    Signature,
 };
 use ipc_api::cross::IpcEnvelope;
 use ipc_api::staking::{StakingChangeRequest, ValidatorInfo};
@@ -287,25 +288,28 @@ pub trait BottomUpCheckpointRelayer: Send + Sync {
 /// in the child subnet
 #[async_trait]
 pub trait ValidatorRewarder: Send + Sync {
-    /// Obtain the proofs needed for the validator to batch claim the rewards
-    async fn get_validator_claim_proofs(
+    /// Query validator claims, indexed by checkpoint height, to batch claim rewards.
+    async fn query_reward_claims(
         &self,
         validator_addr: &Address,
         from_checkpoint: ChainEpoch,
         to_checkpoint: ChainEpoch,
-    ) -> Result<Vec<ValidatorClaimProof>>;
-    /// Get the reward for specific validator in the current subnet gateway
-    async fn get_validator_activities(
+    ) -> Result<Vec<(u64, ValidatorClaim)>>;
+
+    /// Query validator rewards in the current subnet, without obtaining proofs.
+    async fn query_validator_rewards(
         &self,
         validator: &Address,
         from_checkpoint: ChainEpoch,
         to_checkpoint: ChainEpoch,
-    ) -> Result<Vec<ValidatorSummary>>;
-    /// Claim the reward in batches
-    async fn batch_claim(
+    ) -> Result<Vec<(u64, ValidatorData)>>;
+
+    /// Claim validator rewards in a batch for the specified subnet.
+    async fn batch_subnet_claim(
         &self,
         submitter: &Address,
         reward_claim_subnet: &SubnetID,
-        payloads: Vec<BatchClaimProofs>,
+        reward_origin_subnet: &SubnetID,
+        claims: Vec<(u64, ValidatorClaim)>,
     ) -> Result<()>;
 }
diff --git a/ipc/wallet/Cargo.toml b/ipc/wallet/Cargo.toml
index 11cd5d9461..02c02f6922 100644
--- a/ipc/wallet/Cargo.toml
+++ b/ipc/wallet/Cargo.toml
@@ -15,7 +15,7 @@ base64 = { workspace = true }
 blake2b_simd = { workspace = true }
 bls-signatures = { version = "0.13.0", default-features = false, features = ["blst"] }
 ethers = { workspace = true, optional = true }
-fvm_shared = { workspace = true }
+fvm_shared = { workspace = true, features  = ["crypto"] }
 hex = { workspace = true }
 libc = "0.2"
 libsecp256k1 = { workspace = true }