SDK v3.5.3 — Channel-Driven Multi-Round Negotiation

@agirails/sdk@3.5.3 ships AIP-2.1 §6 NegotiationChannel — both buyer and provider agents poll a relay, neither needs to host an HTTP server. Multi-round counter-counter exchange now runs autonomously. Plus security and mainnet-compat fixes from two audit passes and one community review.

Install

npm install @agirails/sdk@3.5.3

NegotiationChannel — single transport

The 3.4.x setReceivedQuote / setCounterAccepted API is replaced by one abstraction:

interface NegotiationChannel {
  post(txId: string, envelope: NegotiationMessage): Promise<void>;
  subscribeTxId(txId, onMessage): Subscription;       // buyer's view
  subscribeAgent(agentDid, onMessage): Subscription;  // provider firehose
}

Two implementations ship:

• RelayChannel — default. Polls agirails.app/api/v1/negotiations/.... Both sides use it; no inbound port required.
• MockChannel — in-memory for tests.

Verification + dedup happens INSIDE the channel — orchestrators never see unverified payloads.

Multi-round inner loop

BuyerOrchestrator walks up to policy.rounds_per_provider counter exchanges:

await first quote
for round in 0..rounds_per_provider:
  evaluate(quote, roundsUsedSoFar = round)
    accept  → on-chain acceptQuote+linkEscrow
    reject  → on-chain CANCELLED
    counter → post counter, await:
              counteraccept → bind to last counter, on-chain accept+link
              new quote     → loop with new quote
              timeout       → CANCELLED

ProviderPolicy gains:

• counter_strategy: 'walk' | 'concede' (default walk)
• concede_pct (default 30 — concede 30% of gap toward floor each round)
• max_requotes (default 2)

actp agent — channel-driven daemon

actp serve from 3.4.x is replaced by actp agent:

actp agent --policy provider-policy.json --network base-sepolia

Polls relay for incoming counters across all txIds where the provider is listed. Watches on-chain for new INITIATED txs and auto-quotes per ProviderPolicy. Auto-respond per counter_strategy. No inbound port — pure outbound HTTPS.

actp serve kept as legacy alias through 3.5.x; will be removed in 3.6.0.

Security audit — 8 fixes

Two parallel audit passes after 3.5.0 caught 8 issues (commit log: 3fc1fb7, aa30a70):

#	Issue	Severity
1	Re-quote maxPrice substitution attack	P0
2	Channel dedup-set poisoned before EIP-712 verify	P0
3	TOCTOU race in 50-message Postgres cap	P1
4	Relay envelope stored raw POST body	P1
5	NaN cursor silently fell back to row 0	P1
6	NegotiationChannel types missing from public exports	P1
7	BuyerOrchestrator silent fall-through on partial context	P1
8	_waitForNextMessage microtask race	P1

All ship with regression tests.

Mainnet compat (community review report)

A community review from a real Base Mainnet end-to-end test (provider on 3.4.1, requester on 2.7.0, settled successfully via local hotfixes) caught three issues blocking new integrators (commit ae86c20):

• Legacy 16-field ABI fallback — Deployed Base Mainnet kernel returns the 16-field getTransaction tuple; the current 19-field ABI failed decode and BlockchainRuntime swallowed it as null, surfacing as TX_NOT_FOUND. Now: LEGACY_GET_TRANSACTION_IFACE precompiled fallback retries on BAD_DATA.
• Error propagation — BlockchainRuntime.getTransaction returns null only for confirmed-missing transactions; decode/RPC/network errors propagate.
• Default mainnet RPC → publicnode — mainnet.base.org returns response shapes ethers v6.15.0 misinterprets as reverts on EntryPoint.getNonce. BASE_MAINNET_RPC env override unchanged.

Breaking changes vs 3.4.1

• BuyerOrchestrator: removed setReceivedQuote, setCounterAccepted. New surface: pass a negotiationChannel and call negotiate().
• BuyerNegotiationContext.channel → negotiationChannel. Type widened to NegotiationChannel.
• ProviderOrchestrator: constructor needs providerDID + negotiationChannel for start(). quote() is now 2-arg.
• ProviderPolicyEngine.evaluateCounter widened to (counter, lastQuoteAmount, requotesUsed), returns 'accept' | 'reject' | 'requote'.

Verification

Check	Result
TypeScript compilation	0 errors
Test suite	2,184 passing
ESLint	0 warnings

Resources

• npm Package
• GitHub Repository
• AIP-2.1 spec
• Documentation
• Discord