[Master] Critter Stack 2026

[jeremydmiller]

Status: in-flight (JasperFx-side foundations largely shipped; per-product master plans picking them up)
Cross-repo umbrella for the Critter Stack 2026 release wave.
Reference: Critter Stack 2026 (jeremydmiller.com, 2026-04-29)

This issue is the north star for the 2026 wave. It does not track implementation work directly — it links to per-product master plans (each lives in its own repo) and to cross-cutting pillar plans (here in JasperFx). Those, in turn, link to concrete implementation issues.

The three pillars

1. Cold-start performance. Make every Critter Stack product viable in serverless / cold-start scenarios — fewer dependencies on the hot path, faster first-request latency, smaller publish footprint. → [Pillar] Cold-start performance #212
2. AOT compliance. All shipped libraries publish-AOT-clean (or trim-clean with explicit annotations). The Roslyn pipeline becomes dev-time-only for code-generation users; Wolverine's runtime codegen stays but is annotated. → [Pillar] AOT compliance #213
3. Dedupe Marten ↔ Polecat. Consolidate shared infrastructure into Weasel.Core / JasperFx.Events / shared utilities so Polecat 4 and Marten 9 stop carrying parallel copies. → [Pillar] Dedupe Marten ↔ Polecat #214

Per-product master plans

Product	Target version	Master plan
JasperFx	2.0	#215
JasperFx.Events	2.0	#216
Weasel	9.0	JasperFx/weasel#263
Marten	9.0	JasperFx/marten#4349
Polecat	4.0	JasperFx/polecat#46
Wolverine	6.0	JasperFx/wolverine#2715
CritterWatch	1.0	JasperFx/CritterWatch#148 (Explorer + Event Modeling swim-lane + Projection Step-through)
Bobcat	exploratory	not committed

Cross-cutting decisions (apply to every product unless noted)

• Drop net8.0. Add net11.0 when it ships. Targets are net9.0;net10.0 in the interim. ✅ done in JasperFx
• Source generators replace runtime reflection where feasible. Exception: Wolverine stays on runtime codegen (per blog: "not remotely possible" to source-generate). Wolverine + Marten both lean on JasperFx's existing dotnet run -- codegen write for pre-generation.
• Defaults flip toward "best-observed-perf" config — including settings previously gated as opt-in due to schema impact. AI-assisted migration tooling is the mitigation.
• Obsolete APIs accumulated since the last major are removed in this wave.

Already shipped against this plan

• ✅ JasperFx 2.0 branch cutover — 1.0 maintenance branch frozen, main is now 2.0, all packages at 2.0.0-alpha.1 (JasperFx, JasperFx.Events, three source generators).
• ✅ JasperFx PR AOT prep: introduce ITypeLoader abstraction so the Roslyn pipeline is excludable under PublishAot #190 — ITypeLoader abstraction + JasperFx.RuntimeCompiler package split. Apps in Static mode no longer reference Roslyn at all. (AOT pillar.)
• ✅ JasperFx PR AOT prep: annotate CloseAndBuildAs<T> + add a delegate-factory escape hatch for hot-path callers #191 — CloseAndBuildAs<T> AOT annotations + GenericFactoryCache delegate cache as the hot-path-friendly escape hatch. (AOT + cold-start.)
• ✅ JasperFx PR Stabilize codegen ordering for byte-identical output across runs #196 — deterministic codegen ordering. Enables byte-identical pre-generated code, prerequisite for treating it as a build artifact. (Cold-start.)
• ✅ JasperFx.Events 2.0 API widening — IInlineProjection.ApplyAsync widened; GenerationRules.Clone added. (Foundation for the per-product cold-start work.)
• ✅ JasperFx AOT pillar essentially complete — IsAotCompatible=true on JasperFx.csproj + JasperFx.Events.csproj, 236 → 0 IL warnings, AOT smoke-test consumer (src/JasperFx.AotSmoke/). PRs Annotate CodeGeneration/Services reflective surface for AOT (closes #255) #257–Annotate remaining AOT pillar tail in JasperFx (74 → 0 warnings) #260 (JasperFx side) + Annotate JasperFx.Events Aggregation cluster for AOT (#262, slice 1/4) #264–Annotate JasperFx.Events tail surfaces for AOT (#262, slice 4/4) #267 (JasperFx.Events side). See [Pillar] AOT compliance #213.
• ✅ AOT publish guide — docs/codegen/aot.md (PR Add 'Publishing AOT with JasperFx' end-to-end guide #263).
• ✅ JasperFx 1.x → 2.0 migration guide — docs/migration-guide.md (PR Add JasperFx 1.x → 2.0 migration guide #242).
• ✅ Codegen snapshot invalidation contract — Phase 1 — PR Codegen snapshot invalidation contract (#243 Phase 1) #244 (Codegen startup snapshot + optional source-generator applicator (shared mechanism for Marten + Wolverine) #243 substrate for the Tier 2 cold-start mechanism shared by Marten + Wolverine).
• ✅ JasperFx.Events lift-ups for dedupe ([Pillar] Dedupe Marten ↔ Polecat #214) — IEventStream + session/daemon contracts (PR Lift IEventStream, session API + daemon contracts to JasperFx.Events … #268), StreamCompactingRequest<T> (PR Lift StreamCompactingRequest<T> into JasperFx.Events.Protected (#269) #274), FetchForWritingByTags<T> + IEventBoundary<T> (PR Lift FetchForWritingByTags<T> + IEventBoundary<T> to JasperFx.Events (#270) #275).

Explicitly out of scope for 2026

• Wolverine source-generator conversion
• UI-driven event sourcing tooling (separate from CritterWatch operator UI)
• Reqnroll integration commitment (left open as a maybe-later)
• Bobcat firm release date

Sequencing notes

1. JasperFx 2.0 + JasperFx.Events 2.0 are the foundation. Stable alphas before any downstream product cuts a release alpha.
2. Weasel 9.0 ships as the database-manipulation substrate, but its stability is gated on Marten 9 consuming each migrated row.
3. Marten 9 + Polecat 4 ship simultaneously. The dedupe pillar migration is iterative and bidirectional between the two.
4. Wolverine 6 is independent of the dedupe pillar; ships against the JasperFx 2.0 foundation on its own schedule.
5. CritterWatch 1.0 rides on top of the JasperFx-layer foundations from rows 1 + 9 of CritterWatch#148 (jasperfx#209, jasperfx#211), the Marten/Polecat explorer + projection-replay impls (rows 2/3 + 10/11), and the Wolverine saga diagnostics (row 4 — wolverine#2713). CritterWatch's own implementation rows (5–8 + 12) develop in parallel against submodule branches; promotion to NuGet packages follows the Phase A→D sequence documented in Make composite projections play well with multi-tenancy #148.

How to read this tree

[Master] Critter Stack 2026                       ← this issue (JasperFx)
├── [Pillar] Cold-start performance               ← JasperFx#212
├── [Pillar] AOT compliance                       ← JasperFx#213
├── [Pillar] Dedupe Marten ↔ Polecat              ← JasperFx#214
├── [Master] JasperFx 2.0                         ← JasperFx#215
├── [Master] JasperFx.Events 2.0                  ← JasperFx#216
├── [Master] Weasel 9.0                           ← weasel#263
├── [Master] Marten 9.0                           ← marten#4349
├── [Master] Polecat 4.0                          ← polecat#46
├── [Master] Wolverine 6.0                        ← wolverine#2715
└── [Master] CritterWatch 1.0                     ← CritterWatch#148

[jeremydmiller]

Handoff status — 2026-05-11

This comment is a handoff snapshot for a fresh agent session ("Dispatch" mode) to pick up where today's work left off. Self-contained — no prior chat history needed beyond the repo state and linked issues.

What landed today

Packages on NuGet

• JasperFx 2.0.0-alpha.1 family: JasperFx, JasperFx.Events, JasperFx.Events.SourceGenerator, JasperFx.SourceGeneration, JasperFx.RuntimeCompiler.
• Weasel 9.0.0-alpha.1 family: Weasel.Core, Weasel.Postgresql, Weasel.SqlServer, Weasel.MySql, Weasel.Oracle, Weasel.Sqlite, Weasel.EntityFrameworkCore.

Repo cutovers complete

• JasperFx: main = 2.0 dev, 1.0 is the maintenance branch.
• Marten: master = 9.0 dev, 8.0 is the maintenance branch.
• Weasel: master = 9.0 dev, 8.0 is the maintenance branch.
• Polecat: not yet cut over — main is still Polecat 3.x; 4.0 dev happens via feature branches into main.
• Wolverine: not yet cut over — master still 5.x; 6.0 dev happens via feature branches into master.

Marten master — today's commits (8 + 1 squash-merge)

1. Detach from sibling-repo project refs; bump central package versions to alpha.
2. Migrate to Weasel.Core.BulkInsertMode (audit row JasperFx/weasel#264).
3. Fix launchSettings.json dotnetRunMessages (.NET SDK 10.0.203 strict).
4. Strip residual Marten.slnx Attached-folder refs.
5. Regression test for mt_streams snapshot columns — author preserved as @BEQ25-coder (closes #4348).
6. LinqTestsTypes: drop sibling-repo JasperFx.csproj project ref.
7. Force-materialize document mappings in IDocumentStoreUsageSource.TryCreateUsage (fixes 3 CritterWatch descriptor tests).
8. Squash-merge of #4352 — Migrate to Weasel.Core.OperationRole (audit row close-out).

Polecat PRs open

• #47 — CascadeAction migration to Weasel.Core (audit row close-out).
• #50 — BulkInsertMode adoption: drop local enum, consume Weasel.Core's, add OverwriteIfVersionMatches switch case that throws NotSupportedException pointing at Rebuild the old Marten "projections" command #48.
• #49 — FlatTableProjection SQL Server case-sensitivity fix (the human owner's WIP — do not touch).

Documentation trackers filed

• Marten #4355 — Marten 8 → 9 migration guide.
• Polecat #51 — Polecat 3 → 4 migration guide.
• Wolverine #2717 — Wolverine 5 → 6 migration guide.

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Next steps, ranked by readiness

Hot — ready to pick up immediately

1. Marten #4353 (IStorageOperation refactor) — stacked PR. Was waiting on #4352 (now merged). Needs:

   • git checkout feature/extend-weasel-storage-operation && git rebase origin/master
   • Force-push, wait for CI
   • The PR's content is independently verified safe (drops sync Postprocess overload from IStorageOperation, extends Weasel.Core.IStorageOperation). Build clean locally before push.
   • Pre-existing master CI failure remains: #4354 (test-code-gen ArgumentNullException). Admin-merge once everything else is green.

2. Marten #4354 (codegen ArgumentNullException) — pre-existing master bug from #4309 AOT-friendly tier-1 work. Symptom: codegen write runs ~5 file emissions then throws ArgumentNullException: Value cannot be null (Parameter 'type') from DocumentProviderBuilder.BuildProvider<T> at line 83. Root cause is _providerType being null after StaticOnlyCodeFileLoader.Initialize — AttachTypes/FindPreGeneratedType returns null on the freshly-compiled assembly. Likely a namespace/name-mismatch fallout from the JasperFx 2.0 codegen rules change. Issue body has full stack trace + analysis.

3. Polecat PR review pass — Importing quite a bit of projection code from Marten #47 + Eliminate SnapshotAction and replace with a tuple of (Snapshot, ActionType) #50 both UNSTABLE in CI when last checked. Worth confirming whether the failures are pre-existing on Polecat main or PR-introduced, then merge.

4. Audit row JasperFx/jasperfx#220 (SnapshotLifecycle) — only Rule-1 dedup row from the events slice. Needs:

   • Add JasperFx.Events.SnapshotLifecycle enum (Inline, Async).
   • Publish a JasperFx.Events 2.0.0-alpha.2 (or hold for batch).
   • File Marten + Polecat adoption follow-ups (drop local enum, consume the new one).

5. CritterStackScalability open PRs — PR #1 (cold-start harness) + PR #2 (docker postgres:17 swap). Both verified working end-to-end; ready to merge.

Warm — cutover or planning needed

6. Polecat 4 cutover — mirror the Marten/Weasel pattern:

   • Force-overwrite origin/3.0 (if it exists as a stale branch like Marten's 8.0 was) with origin/main tip as the new 3.x maintenance branch. Need to check first.
   • Fast-forward origin/main to the Polecat 4.0 development tip (once accumulated work warrants it).
   • This unblocks Polecat 4.0.0-alpha.1 publishing.

7. Wolverine 6 cutover — same pattern. Master plan is in #2715 but no Wolverine-side dev work has started yet that requires a branch cutover. Could be deferred until there's actual 6.0 development.

8. CritterWatch 1.0 master plan — was explicitly deferred earlier in the planning conversation. Ready to pick up if the human wants. Needs: survey CritterWatch repo, identify ongoing PRs that should land in this wave, file master plan in JasperFx with cross-links.

Cold — later phases

• Pillar #214 next audit slice: multi-tenancy. After events slice's last row (Dedup audit: move SnapshotLifecycle enum to JasperFx.Events #220) closes.
• Pillar #213 per-product AOT audits: Marten + Polecat + Wolverine each need a sub-issue for reflective-call-site annotation work.
• Pillar #212 cold-start follow-ups: Wolverine cold-start child binary in CritterStackScalability + Static-mode measurements once pre-generated code can be baked into a child.

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Watch-outs for a fresh agent

• Do NOT disturb Polecat checkout's working tree. The human has uncommitted work on the fix-issue-45-flattable-case branch at ~/code/polecat. Use git worktree add /tmp/<name> -b <new-branch> origin/main for any Polecat work.
• Do NOT disturb Weasel checkout's working tree. The human has uncommitted work on fix-sqlserver-column-case at ~/code/weasel. Same worktree pattern if needed.
• The Marten audit rebase + force-push pattern is established. PR branches start at feature/<thing>, get force-pushed after rebase, admin-merge is acceptable when CI failures are pre-existing on master and the PR diff is verified clean.
• .claude/worktrees/ directories appear in some repos. Don't git add -A blindly — those are sibling worktrees and shouldn't be committed as submodules. (Hit this once today; recovered with git rm --cached.)
• The "nuke attach" pattern in Marten + Polecat replaces NuGet package refs with local sibling-repo project refs for dev. Always run ./build.sh detach before commit/CI; the user's master branches expect package refs.

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Open audit punch list (Marten ↔ Polecat dedup)

Parent: JasperFx/jasperfx#218 (database slice) + #219 (events slice).

Row	Sub-issue	Status
OperationRole	JasperFx/marten#4350	✅ merged via #4352
CascadeAction	JasperFx/polecat#47	PR #47 open
IStorageOperation	JasperFx/marten#4351	PR #4353 open, stacked on #4352
BulkInsertMode (Weasel side)	JasperFx/weasel#264	✅ landed in Weasel 9.0.0-alpha.1
BulkInsertMode (Marten side)	—	✅ landed on master
BulkInsertMode (Polecat side)	—	PR #50 open
OverwriteIfVersionMatches impl	JasperFx/polecat#48	tracked for later (needs version-metadata API)
SnapshotLifecycle	#220	not started; gated on JasperFx.Events 2.x

[jeremydmiller]

Continued — 2026-05-11 (second session)

Picking up Hot-tier items from the handoff snapshot above.

Landed this session

• JasperFx #220 — SnapshotLifecycle audit row closed.
  • JasperFx.Events.Projections.SnapshotLifecycle enum added in b54b18f on main.
  • JasperFx.Events source version bumped to 2.0.0-alpha.2 (not yet published).
  • Marten adoption follow-up: marten#4356.
  • Polecat adoption follow-up: polecat#52.

Triage notes for next pickup

• Marten #4353 — already MERGED. Handoff above was stale on this point.
• Polecat Importing quite a bit of projection code from Marten #47 — number doesn't exist as an open PR; feature/use-weasel-cascade-action was either merged separately or rolled into a different PR. Only Eliminate SnapshotAction and replace with a tuple of (Snapshot, ActionType) #50 is currently open from the audit work.
• Polecat #50 — polecat workflow failing on both default + edge tiers; aspnetcore + efcore companion workflows green. Worth confirming whether the failures are pre-existing on main before merging. Not investigated this session.
• CritterStackScalability #1 + #2 — both still MERGEABLE/CLEAN, no CI configured. I authored both; deferred merging pending explicit go-ahead from Jeremy.

Open audit punch list (refreshed)

Row	Sub-issue	Status
OperationRole	marten#4350	✅ merged via #4352
CascadeAction	polecat#47	✅ (number no longer maps to open PR; treat as closed)
IStorageOperation	marten#4351	✅ merged via #4353
BulkInsertMode (Weasel)	weasel#264	✅ landed in 9.0.0-alpha.1
BulkInsertMode (Marten)	—	✅ landed on master
BulkInsertMode (Polecat)	—	polecat#50 open
OverwriteIfVersionMatches impl	polecat#48	tracked (needs version-metadata API)
SnapshotLifecycle	#220	✅ landed on JasperFx main (alpha.2)
SnapshotLifecycle — Marten adoption	marten#4356	new, gated on JasperFx.Events alpha.2 publish
SnapshotLifecycle — Polecat adoption	polecat#52	new, gated on JasperFx.Events alpha.2 publish

The dedup events slice is now down to two follow-up adoption issues — both gated on the JasperFx.Events 2.0.0-alpha.2 publish. That can ride to the next batch alongside whatever the multi-tenancy slice produces.