AlgoVoi x402 Implementation — Showcase
We've implemented x402 spec on four non-EVM chains as part of AlgoVoi — a multi-tenant payment infrastructure layer for Algorand, VOI, Hedera, and Stellar.
What we built
A drop-in Python adapter (x402_agents_algovoi.py) that:
- Emits spec v1 compliant
X-PAYMENT-REQUIRED headers (x402Version: 1, accepts array, CAIP-2 network IDs, string microunit amounts)
- Verifies
payload.signature proof format with payload.tx_id fallback
- Covers all four chains with a single adapter — zero pip dependencies, stdlib only
- Works as Flask/Django/FastAPI middleware or manual WSGI check
Test results
76/76 unit tests passing — spec format, CAIP-2 mappings, microunit conversion, proof formats, all four networks.
End-to-end smoke tested on 13 April 2026 — real 0.01 USDC payments on each chain, x402/verify returning verified: true:
| Chain |
Network ID |
Asset |
| Algorand mainnet |
algorand:mainnet |
USDC ASA 31566704 |
| VOI mainnet |
voi:mainnet |
aUSDC ARC200 302190 |
| Hedera mainnet |
hedera:mainnet |
USDC HTS 0.0.456858 |
| Stellar pubnet |
stellar:pubnet |
USDC Circle |
CAIP-2 conventions for non-EVM chains
Working out the CAIP-2 identifiers for these chains required some research — we've published our findings as a reference document since there's no canonical source for Algorand/VOI/Hedera/Stellar CAIP-2 conventions:
caip2-algorand.md
Covers identifier format, asset notation, address formats, and implementation notes (e.g. Hedera TX ID normalisation, Stellar decimal-to-microunit conversion).
Links
Why this matters for x402
Most x402 implementations target EVM chains. Algorand and Stellar together process a significant volume of Circle USDC — opening x402 to these networks means AI agents can pay for services using USDC that was never on an EVM chain to begin with. VOI extends this to AVM-native DeFi. Hedera adds HTS token support.
The CAIP-2 conventions document is intended as a contribution to anyone else building x402 on these networks — if there's a better place for it (the namespaces registry, a spec PR, etc.) we're happy to move it there.
AlgoVoi x402 Implementation — Showcase
We've implemented x402 spec on four non-EVM chains as part of AlgoVoi — a multi-tenant payment infrastructure layer for Algorand, VOI, Hedera, and Stellar.
What we built
A drop-in Python adapter (
x402_agents_algovoi.py) that:X-PAYMENT-REQUIREDheaders (x402Version: 1,acceptsarray, CAIP-2 network IDs, string microunit amounts)payload.signatureproof format withpayload.tx_idfallbackTest results
76/76 unit tests passing — spec format, CAIP-2 mappings, microunit conversion, proof formats, all four networks.
End-to-end smoke tested on 13 April 2026 — real 0.01 USDC payments on each chain,
x402/verifyreturningverified: true:algorand:mainnetvoi:mainnethedera:mainnetstellar:pubnetCAIP-2 conventions for non-EVM chains
Working out the CAIP-2 identifiers for these chains required some research — we've published our findings as a reference document since there's no canonical source for Algorand/VOI/Hedera/Stellar CAIP-2 conventions:
caip2-algorand.md
Covers identifier format, asset notation, address formats, and implementation notes (e.g. Hedera TX ID normalisation, Stellar decimal-to-microunit conversion).
Links
Why this matters for x402
Most x402 implementations target EVM chains. Algorand and Stellar together process a significant volume of Circle USDC — opening x402 to these networks means AI agents can pay for services using USDC that was never on an EVM chain to begin with. VOI extends this to AVM-native DeFi. Hedera adds HTS token support.
The CAIP-2 conventions document is intended as a contribution to anyone else building x402 on these networks — if there's a better place for it (the namespaces registry, a spec PR, etc.) we're happy to move it there.