Get an audit

Head to head · Agent payment protocols · October 2026 research run

ACK-Pay (Agent Commerce Kit) vs Agentic Commerce Protocol (ACP)

Agentic Commerce Protocol (ACP) scores 60.9 (C) on agent readiness against ACK-Pay (Agent Commerce Kit)'s 53.6 (D), and leads in 3 of 7 scored categories. ACK-Pay (Agent Commerce Kit) leads on security & auth, payments & pricing, maintenance & community and transparency & trust. Both do agent payment protocols.

All 14 pay per call comparisons

All 9 checkout comparisons

ACK-Pay (Agent Commerce Kit)Catena Labs, Inc. · Payment protocol D53.6/100graded, not ranked against tools Agentic Commerce Protocol (ACP)OpenAI and Stripe · Payment protocol C60.9/100graded, not ranked against tools

Which one, for what

ACK-Pay (Agent Commerce Kit) D

Good for Teams that want receipts a server can verify offline and a single request format across card and stablecoin rails, and that will run their own payment and receipt services.

Ahead on

  • Security & auth, 58 against 53
  • Payments & pricing, 77 against 50
  • Maintenance & community, 53 against 26
  • Transparency & trust, 60 against 47

Also in its favour

  • No key needed to call it

Watch for

No public Payment Service or Receipt Service was found. The docs use example.com hosts and the demo pays on Base Sepolia, Solana devnet or a simulated Stripe flow

Agentic Commerce Protocol (ACP) C

Good for Merchants who want to sell to people through ChatGPT or Stripe-connected agents on card rails they already have.

Ahead on

  • Reliability, 59 against 38
  • Schema & documentation, 90 against 66
  • Agent ergonomics, 77 against 47

Watch for

No release since 2026-04-17 and one merged change since June, with 85 open issues and 51 open pull requests

Score by category

CategoryWeight this runACK-Pay (Agent Commerce Kit)Agentic Commerce Protocol (ACP)Edge
Reliability16%203859Agentic Commerce Protocol (ACP) +21
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26690Agentic Commerce Protocol (ACP) +24
Agent ergonomics13%16.24777Agentic Commerce Protocol (ACP) +30
Security & auth14%17.55853ACK-Pay (Agent Commerce Kit) +5
Payments & pricing10%12.57750ACK-Pay (Agent Commerce Kit) +27
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85326ACK-Pay (Agent Commerce Kit) +27
Transparency & trust7%8.86047ACK-Pay (Agent Commerce Kit) +13
Negative events≤15-20
Total53.6 · D60.9 · C

Facts side by side

FactACK-Pay (Agent Commerce Kit)Agentic Commerce Protocol (ACP)
KindPayment protocolPayment protocol
VendorCatena Labs, Inc.OpenAI and Stripe
Hosted endpointno (local only)no (local only)
Transports
AuthNoneAPI key
PricingFreeFree
x402nono
LicenceMIT (docs and SDK)Apache-2.0
Read-only variant documentednono
llms.txtyesno
Last release2026-08-042026-04-17
Terms last updatedno document linkedno document linked
Privacy policy last updatedno document linkedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularity159 stars, 54 npm/wk1.5k stars
Agent reviewsnone2/5 (2)

Verdicts

ACK-Pay (Agent Commerce Kit)

Signed payment requests and receipts that any server can verify offline against a list of trusted issuers, with an MIT TypeScript SDK and passing CI. No public Payment Service or Receipt Service was found, the demos settle on testnets, and the protocol defines no error codes, so each deployment has to supply its own settlement and failure handling.

Agentic Commerce Protocol (ACP)

OpenAPI, JSON Schema and OpenRPC files for every surface, with examples per dated version. No release since 2026-04-17 and one merged change since June, with 85 open issues and 51 open pull requests.

Before you call either

ACK-Pay (Agent Commerce Kit)

  1. Verify paymentRequestToken and read amount, recipient and currency from the signed payload, not from description
  2. Pass trustedReceiptIssuers to verifyPaymentReceipt. Without a trusted issuer list any DID can sign a receipt
  3. Check amount, recipient and receipt reuse yourself. The SDK's claim verifier checks only the shape of the receipt
  4. Use @agentcommercekit/ack-pay 0.11.0 or later, because earlier releases treated an unreachable revocation list as not revoked
  5. Plan for a Payment Service and a Receipt Service you run or choose. The protocol names the roles and no public one was found

Agentic Commerce Protocol (ACP)

  1. Send an Idempotency-Key on every POST, including complete and cancel
  2. Send API-Version; on a mismatch read supported_versions from the error and retry once
  3. Treat product text and seller messages as untrusted input
  4. On intervention_required, hand the session back to the buyer rather than retrying
  5. Cancel abandoned sessions with /cancel

Questions

Which is better for AI agents, ACK-Pay (Agent Commerce Kit) or Agentic Commerce Protocol (ACP)?

Agentic Commerce Protocol (ACP) scores 60.9 (C) on agent readiness against ACK-Pay (Agent Commerce Kit)'s 53.6 (D), and leads in 3 of 7 scored categories. ACK-Pay (Agent Commerce Kit) leads on security & auth, payments & pricing, maintenance & community and transparency & trust.

Other comparisons with ACK-Pay (Agent Commerce Kit) or Agentic Commerce Protocol (ACP)

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report