Adding Future Chains — Galliun SDK Docs

Galliun MVP supports Sui and Solana only. New chains follow a consistent pattern across API verification, SDK wallet modules, and platform payment rails.

SDK side

Create a wallet module at packages/sdk/src/chains/<chain>/
Implement PaymentWalletAdapter with address() and pay() — the pay() method must execute an atomic direct split (all legs in one transaction)
Export a factory function from packages/sdk/src/index.ts
Update SDK docs in apps/docs and engineering docs in docs/supported-chains.md

Platform side

Create API verification adapter at apps/api/src/payments/adapters/<chain>.ts
Add chain to SUPPORTED_CHAINS in @galliun/shared
Configure payment rails (RPC, network, provider recipient, platform fee recipient, USDC asset, decimals)
Register adapter in apps/api/src/bootstrap.ts
Update .cursor/rules/supported-chains-source-of-truth.mdc and docs/supported-chains.md

Payment config requirements

Each chain needs:

RPC URL
Network name (mainnet/testnet/devnet)
Provider recipient address (from org payment rail)
Platform fee recipient address (from API env: GALLIUN_*_PLATFORM_FEE_RECIPIENT)
USDC asset identifier (Sui coin type or Solana mint)
Decimals (6 for USDC)

Verifier expectations

Transaction must exist and succeed
Payer must match proof (fee payer / sender where determinable)
Payer must not equal any split recipient address
Each split leg must receive the exact required amount
Asset type must match the requirement and env config
Network must match config

Replay protection

All chains use the shared Convex claimPayment flow. Chain adapters verify on-chain only — never bypass replay checks.

Do not

Put chain-specific logic in x402 middleware
Skip Convex claim before on-chain verification
Hardcode chain logic in route handlers
Reintroduce single-recipient exact or custodial treasury flows

Removed chains

EVM/Base adapters, the finance worker, and custodial treasury flows were removed. See Base / EVM (removed).