{ "data": { "a": { "slug": "ack-pay", "name": "ACK-Pay (Agent Commerce Kit)", "vendor": "Catena Labs, Inc.", "vendorUrl": "https://www.agentcommercekit.com", "kind": "protocol", "category": "pay-per-call", "summary": "ACK-Pay is the open payment protocol in Agent Commerce Kit from Catena Labs. A server returns a signed Payment Request, the client pays through a Payment Service and retries with a receipt issued as a W3C Verifiable Credential.", "url": "https://www.anchorterminal.com/tools/ack-pay", "markdownUrl": "https://www.anchorterminal.com/tools/ack-pay.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/ack-pay.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/ack-pay.json", "repo": "https://github.com/agentcommercekit/ack", "license": "MIT (docs and SDK)", "transports": [], "packages": [ { "registry": "npm", "name": "@agentcommercekit/ack-pay" }, { "registry": "npm", "name": "agentcommercekit" } ], "auth": "none", "authNotes": "No account or key. Servers sign Payment Requests with a key bound to a DID, and Receipt Services sign receipts that servers check against their own list of trusted issuer DIDs. Identity checks between parties can use ACK-ID.", "pricing": "free", "pricingNotes": "No protocol fee, and the SDK is MIT with nothing to buy. Settlement costs depend on the Payment Service and rail a deployment chooses. The docs say conversion and bridging fees should be shown to the client. No public Payment Service with published prices was found.", "priceSummary": "Free", "where": "spec", "x402": { "level": "no", "evidence": "A payment protocol, not a tool that accepts payment. The docs describe x402 as fitting the ACK-Pay pattern and list acting as an x402 facilitator as planned research (checked 2026-10-09).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 159, "npmWeekly": 54, "pypiWeekly": null, "asOf": "2026-10-09" }, "docsUrl": "https://www.agentcommercekit.com/ack-pay/introduction", "llmsTxt": "https://www.agentcommercekit.com/llms.txt", "capabilities": [ "payments.protocol", "payments.stablecoin" ], "tags": [ "protocol", "verifiable-credentials", "did", "receipts", "typescript", "mit", "llms-txt" ], "lastRelease": "2026-08-04", "graded": true, "anchor": { "graded": true, "score": 53.6, "grade": "D", "agentReady": false, "rank": 0, "ranked": false, "notRankedWhy": "A protocol, graded on the same scale but not ranked against tools", "rankOf": 950, "categoryRank": 4, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 47, "maintenance": 53, "payments": 77, "reliability": 38, "schema": 66, "security": 58, "transparency": 60 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-09" }, "negative": -2, "negativeNotes": [ "2026-08-04, @agentcommercekit/ack-pay 0.11.0 fixed a revocation check that treated any failure to fetch or parse the status list as not revoked, so `verifyPaymentReceipt` accepted revoked credentials. The changelog describes the flaw in full and the repository has no published advisory. Fixed and documented, so we deduct 2 (https://github.com/agentcommercekit/ack/blob/main/packages/ack-pay/CHANGELOG.md, https://github.com/agentcommercekit/ack/security/advisories)" ], "verdict": "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.", "bestFor": "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.", "strengths": [ "Receipts are W3C Verifiable Credentials signed by a Receipt Service, so a server checks payment without calling the payment system", "One Payment Request can list several options, such as USDC on Base and a card payment through Stripe, each with its own Payment Service", "Docs and code are MIT, with llms.txt and a Markdown copy of every docs page", "The SDK exports Valibot and Zod schemas for the request, the option and the receipt claim", "CI builds, lints and tests on every push, and the last five runs on main on the page read passed" ], "weaknesses": [ "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", "The protocol defines no error codes, idempotency key or retry header. The operations page tells implementers to design their own", "One SDK, in TypeScript, at 0.11.0. One release in the last 90 days, with nine changesets waiting on main, including a receipt option check", "0.11.0 fixed a revocation check that accepted revoked credentials when the status list was unreachable. No GitHub advisory was published", "Open issue 222 of 21 September 2026 reports that `expiresAt` on a Payment Request is never enforced", "No terms, privacy policy, status page or security.txt on agentcommercekit.com" ], "agentNotes": [ "Verify `paymentRequestToken` and read amount, recipient and currency from the signed payload, not from `description`", "Pass `trustedReceiptIssuers` to `verifyPaymentReceipt`. Without a trusted issuer list any DID can sign a receipt", "Check amount, recipient and receipt reuse yourself. The SDK's claim verifier checks only the shape of the receipt", "Use `@agentcommercekit/ack-pay` 0.11.0 or later, because earlier releases treated an unreachable revocation list as not revoked", "Plan for a Payment Service and a Receipt Service you run or choose. The protocol names the roles and no public one was found" ], "metrics": { "kind": "spec", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "D", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 53.6 } ], "editorialScores": { "ergonomics": 47, "maintenance": 53, "payments": 77, "reliability": 38, "schema": 66, "security": 58, "transparency": 63 }, "provenanceScore": 57 }, "connect": { "install": "npm i @agentcommercekit/ack-pay" }, "letme": { "capability": "https://letme.dev/payments.protocol", "tool": "https://letme.dev/ack-pay" }, "area": "payments", "provenance": { "legalEntity": "Catena Labs, Inc.", "domain": "agentcommercekit.com", "domainRegistered": "2025-05-02", "domainNote": "The docs site names no legal entity. Catena Labs, Inc. is the copyright holder in the repository's LICENCE file and the author in the package manifests. No terms or privacy policy were found for the docs site, so the MIT licence stands in.", "endpointOnVendorDomain": null, "terms": "", "privacy": "", "statusPage": "", "changelog": "https://github.com/agentcommercekit/ack/blob/main/packages/ack-pay/CHANGELOG.md", "securityTxt": "none", "checked": "2026-10-09", "score": 57 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/ack-pay.json", "live": { "slug": "ack-pay", "versions": [ { "registry": "github", "name": "agentcommercekit/ack", "version": "agentcommercekit@0.11.0", "released": "2026-08-04", "seenAt": "2026-10-09T16:36:08.43967526Z" }, { "registry": "npm", "name": "@agentcommercekit/ack-pay", "version": "0.11.0", "seenAt": "2026-10-09T16:36:05.977895912Z" }, { "registry": "npm", "name": "agentcommercekit", "version": "0.11.0", "seenAt": "2026-10-09T16:36:06.897286657Z" } ], "githubStars": 159, "npmWeekly": 54, "pages": [ { "url": "https://raw.githubusercontent.com/agentcommercekit/ack/main/packages/ack-pay/CHANGELOG.md", "kind": "changelog", "status": 200, "checkedAt": "2026-10-09T18:44:49.200254285Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "a86c2ee19456" } ], "updatedAt": "2026-10-09T18:44:49.200254285Z" } }, "answer": "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 \u0026 auth, payments \u0026 pricing, maintenance \u0026 community and transparency \u0026 trust.", "b": { "slug": "acp", "name": "Agentic Commerce Protocol (ACP)", "vendor": "OpenAI and Stripe", "vendorUrl": "https://www.agenticcommerce.dev", "kind": "protocol", "category": "checkout-protocols", "summary": "Open checkout spec from OpenAI and Stripe (2025-09-29).", "url": "https://www.anchorterminal.com/tools/acp", "markdownUrl": "https://www.anchorterminal.com/tools/acp.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/acp.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/acp.json", "repo": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol", "license": "Apache-2.0", "transports": [], "packages": [], "auth": "api-key", "authNotes": "Bearer auth between the agent platform and the seller, plus a card vaulted by the agent's payment provider.", "pricing": "free", "pricingNotes": "No protocol fee. Payment provider pricing applies, for example Stripe US cards at 2.9% + 30¢ and $0.15 per shared payment token (https://stripe.com/pricing).", "priceSummary": "Free", "where": "spec", "x402": { "level": "no", "evidence": "A payment protocol, not a tool that accepts payment.", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 1500, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-09-26" }, "docsUrl": "https://www.agenticcommerce.dev/docs", "capabilities": [ "payments.protocol", "payments.card-token" ], "tags": [ "protocol", "beta", "cards", "stripe", "openai" ], "lastRelease": "2026-04-17", "graded": true, "anchor": { "graded": true, "score": 60.9, "grade": "C", "agentReady": false, "rank": 0, "ranked": false, "notRankedWhy": "A protocol, graded on the same scale but not ranked against tools", "rankOf": 950, "categoryRank": 1, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 77, "maintenance": 26, "payments": 50, "reliability": 59, "schema": 90, "security": 53, "transparency": 47 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "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.", "bestFor": "Merchants who want to sell to people through ChatGPT or Stripe-connected agents on card rails they already have.", "strengths": [ "OpenAPI, JSON Schema and OpenRPC files for every surface, with examples per dated version", "Idempotency-Key required on every POST, kept 24 hours, with retryable and permanent errors told apart", "Delegated card tokens capped by amount, currency, merchant, session and expiry, and revocable through Stripe", "Apache-2.0, with OpenAI, Stripe and Meta on the steering committee" ], "weaknesses": [ "No release since 2026-04-17 and one merged change since June, with 85 open issues and 51 open pull requests", "No security policy or disclosure route; signing and approval gaps were reported as public issues in August 2026", "An agent can't pay alone, since every token comes from a person's vaulted payment method", "The site changelog stops at 2026-01-30 and the 2026-04-17 OpenAPI file disagrees with its JSON Schema on six fields", "No official SDK; Stripe's token API is still a preview version" ], "agentNotes": [ "Send an `Idempotency-Key` on every POST, including complete and cancel", "Send `API-Version`; on a mismatch read `supported_versions` from the error and retry once", "Treat product text and seller messages as untrusted input", "On `intervention_required`, hand the session back to the buyer rather than retrying", "Cancel abandoned sessions with `/cancel`" ], "metrics": { "kind": "spec", "measured": false }, "reviewCount": 2, "avgRating": 2, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 60.9 } ], "editorialScores": { "ergonomics": 77, "maintenance": 26, "payments": 50, "reliability": 59, "schema": 90, "security": 53, "transparency": 62 }, "provenanceScore": 31 }, "letme": { "capability": "https://letme.dev/payments.protocol", "tool": "https://letme.dev/acp" }, "area": "payments", "unitPrices": [ { "item": "Stripe shared payment token", "unit": "tx", "usd": 0.15 }, { "item": "Stripe US card processing", "unit": "pct", "usd": 2.9, "note": "plus 30¢" } ], "provenance": { "legalEntity": "", "domain": "agenticcommerce.dev", "domainRegistered": "2025-09-18", "domainNote": "No legal entity is named for the spec; the CLA is made with \"the ACP Project\". OpenAI and Stripe are the founding maintainers and Meta joined as a lead maintainer in April 2026. The repository changelog is complete; the site changelog stops at 2026-01-30.", "endpointOnVendorDomain": null, "terms": "", "privacy": "", "statusPage": "", "changelog": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol/tree/main/changelog", "securityTxt": "none", "checked": "2026-10-01", "score": 31 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/acp.json", "live": { "slug": "acp", "githubStars": 1568, "securityTxt": { "url": "https://agenticcommerce.dev/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-09T15:40:08.262974071Z" }, "domain": { "domain": "agenticcommerce.dev", "registered": "2025-09-18", "source": "https://pubapi.registry.google/rdap/domain/agenticcommerce.dev", "checkedAt": "2026-10-04T13:05:49.075247226Z" }, "pages": [ { "url": "https://www.agenticcommerce.dev/docs/changelog", "kind": "deprecations", "status": 200, "checkedAt": "2026-10-09T18:47:45.282845461Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "d534cedf2487" }, { "url": "https://stripe.com/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-10-09T18:46:07.321259495Z", "changedAt": "2026-10-08T18:24:54.461479429Z", "fingerprint": "8bbe2c040ac8" } ], "updatedAt": "2026-10-09T18:47:45.282845461Z" } }, "facts": [ { "a": "Payment protocol", "b": "Payment protocol", "name": "Kind" }, { "a": "Catena Labs, Inc.", "b": "OpenAI and Stripe", "name": "Vendor" }, { "a": "no (local only)", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "", "b": "", "name": "Transports" }, { "a": "None", "b": "API key", "name": "Auth" }, { "a": "Free", "b": "Free", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "MIT (docs and SDK)", "b": "Apache-2.0", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "no", "name": "llms.txt" }, { "a": "2026-08-04", "b": "2026-04-17", "name": "Last release" }, { "a": "no document linked", "b": "no document linked", "name": "Terms last updated" }, { "a": "no document linked", "b": "no document linked", "name": "Privacy policy last updated" }, { "a": "", "b": "", "name": "Customer content may train models" }, { "a": "", "b": "", "name": "Terms restrict automated access" }, { "a": "", "b": "", "name": "Terms restrict benchmarking" }, { "a": "", "b": "", "name": "Terms or service can change without notice" }, { "a": "", "b": "", "name": "Arbitration or class-action waiver" }, { "a": "159 stars, 54 npm/wk", "b": "1.5k stars", "name": "Popularity" }, { "a": "none", "b": "2/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "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 \u0026 auth, payments \u0026 pricing, maintenance \u0026 community and transparency \u0026 trust.", "question": "Which is better for AI agents, ACK-Pay (Agent Commerce Kit) or Agentic Commerce Protocol (ACP)?" } ], "goodFor": [ { "aheadOn": [ "Security \u0026 auth, 58 against 53", "Payments \u0026 pricing, 77 against 50", "Maintenance \u0026 community, 53 against 26", "Transparency \u0026 trust, 60 against 47" ], "also": [ "No key needed to call it" ], "goodFor": "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.", "slug": "ack-pay", "watchFor": "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" }, { "aheadOn": [ "Reliability, 59 against 38", "Schema \u0026 documentation, 90 against 66", "Agent ergonomics, 77 against 47" ], "also": null, "goodFor": "Merchants who want to sell to people through ChatGPT or Stripe-connected agents on card rails they already have.", "slug": "acp", "watchFor": "No release since 2026-04-17 and one merged change since June, with 85 open issues and 51 open pull requests" } ], "job": { "capability": "payments.protocol", "name": "Agent payment protocols" }, "others": [ { "json": "https://www.anchorterminal.com/compare/ack-pay-vs-ap2.json", "title": "ACK-Pay (Agent Commerce Kit) vs Agent Payments Protocol (AP2)", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-ap2" }, { "json": "https://www.anchorterminal.com/compare/ack-pay-vs-l402.json", "title": "ACK-Pay (Agent Commerce Kit) vs L402", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-l402" }, { "json": "https://www.anchorterminal.com/compare/ack-pay-vs-mpp.json", "title": "ACK-Pay (Agent Commerce Kit) vs Machine Payments Protocol (MPP)", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-mpp" }, { "json": "https://www.anchorterminal.com/compare/ack-pay-vs-x402.json", "title": "ACK-Pay (Agent Commerce Kit) vs x402", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-x402" }, { "json": "https://www.anchorterminal.com/compare/acp-vs-ap2.json", "title": "Agentic Commerce Protocol (ACP) vs Agent Payments Protocol (AP2)", "url": "https://www.anchorterminal.com/compare/acp-vs-ap2" }, { "json": "https://www.anchorterminal.com/compare/acp-vs-l402.json", "title": "Agentic Commerce Protocol (ACP) vs L402", "url": "https://www.anchorterminal.com/compare/acp-vs-l402" }, { "json": "https://www.anchorterminal.com/compare/acp-vs-mpp.json", "title": "Agentic Commerce Protocol (ACP) vs Machine Payments Protocol (MPP)", "url": "https://www.anchorterminal.com/compare/acp-vs-mpp" }, { "json": "https://www.anchorterminal.com/compare/acp-vs-x402.json", "title": "Agentic Commerce Protocol (ACP) vs x402", "url": "https://www.anchorterminal.com/compare/acp-vs-x402" } ], "scores": [ { "ack-pay": 38, "acp": 59, "by": 21, "edge": "acp", "key": "reliability", "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "ack-pay": 66, "acp": 90, "by": 24, "edge": "acp", "key": "schema", "name": "Schema \u0026 documentation", "weight": 13 }, { "ack-pay": 47, "acp": 77, "by": 30, "edge": "acp", "key": "ergonomics", "name": "Agent ergonomics", "weight": 13 }, { "ack-pay": 58, "acp": 53, "by": 5, "edge": "ack-pay", "key": "security", "name": "Security \u0026 auth", "weight": 14 }, { "ack-pay": 77, "acp": 50, "by": 27, "edge": "ack-pay", "key": "payments", "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "ack-pay": 53, "acp": 26, "by": 27, "edge": "ack-pay", "key": "maintenance", "name": "Maintenance \u0026 community", "weight": 7 }, { "ack-pay": 60, "acp": 47, "by": 13, "edge": "ack-pay", "key": "transparency", "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "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 \u0026 auth, payments \u0026 pricing, maintenance \u0026 community and transparency \u0026 trust. Both do agent payment protocols.", "verdicts": { "ack-pay": "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.", "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." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/ack-pay-vs-acp", "json": "https://www.anchorterminal.com/compare/ack-pay-vs-acp.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/ack-pay-vs-acp.md", "slim": "https://www.anchorterminal.com/compare/ack-pay-vs-acp.min.md" }, "markdown": "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 \u0026 auth, payments \u0026 pricing, maintenance \u0026 community and transparency \u0026 trust. Both do agent payment protocols.\n\n- ACK-Pay (Agent Commerce Kit): grade D, 53.6/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/ack-pay.md · JSON https://www.anchorterminal.com/api/v1/tools/ack-pay.json\n- Agentic Commerce Protocol (ACP): grade C, 60.9/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/acp.md · JSON https://www.anchorterminal.com/api/v1/tools/acp.json\n- All 14 pay per call comparisons: https://www.anchorterminal.com/compare/pay-per-call/index.md\n- All 9 checkout comparisons: https://www.anchorterminal.com/compare/checkout-protocols/index.md\n\n## Which one, for what\n\n### ACK-Pay (Agent Commerce Kit) (D)\n\nGood 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.\n\nAhead on:\n- Security \u0026 auth, 58 against 53\n- Payments \u0026 pricing, 77 against 50\n- Maintenance \u0026 community, 53 against 26\n- Transparency \u0026 trust, 60 against 47\n\nAlso in its favour:\n- No key needed to call it\n\nWatch 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\n\n### Agentic Commerce Protocol (ACP) (C)\n\nGood for: Merchants who want to sell to people through ChatGPT or Stripe-connected agents on card rails they already have.\n\nAhead on:\n- Reliability, 59 against 38\n- Schema \u0026 documentation, 90 against 66\n- Agent ergonomics, 77 against 47\n\nWatch for: No release since 2026-04-17 and one merged change since June, with 85 open issues and 51 open pull requests\n\n\n## Score by category\n\n| Category | Weight | ACK-Pay (Agent Commerce Kit) | Agentic Commerce Protocol (ACP) | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 38 | 59 | Agentic Commerce Protocol (ACP) +21 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 66 | 90 | Agentic Commerce Protocol (ACP) +24 |\n| Agent ergonomics | 13% (16.2 this run) | 47 | 77 | Agentic Commerce Protocol (ACP) +30 |\n| Security \u0026 auth | 14% (17.5 this run) | 58 | 53 | ACK-Pay (Agent Commerce Kit) +5 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 77 | 50 | ACK-Pay (Agent Commerce Kit) +27 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 53 | 26 | ACK-Pay (Agent Commerce Kit) +27 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 60 | 47 | ACK-Pay (Agent Commerce Kit) +13 |\n| Negative events | ≤15 | -2 | 0 | |\n| **Total** | | **53.6 · D** | **60.9 · C** | |\n\n## Facts side by side\n\n| Fact | ACK-Pay (Agent Commerce Kit) | Agentic Commerce Protocol (ACP) |\n| --- | --- | --- |\n| Kind | Payment protocol | Payment protocol |\n| Vendor | Catena Labs, Inc. | OpenAI and Stripe |\n| Hosted endpoint | no (local only) | no (local only) |\n| Transports | | |\n| Auth | None | API key |\n| Pricing | Free | Free |\n| x402 | no | no |\n| Licence | MIT (docs and SDK) | Apache-2.0 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | no |\n| Last release | 2026-08-04 | 2026-04-17 |\n| Terms last updated | no document linked | no document linked |\n| Privacy policy last updated | no document linked | no document linked |\n| Customer content may train models | | |\n| Terms restrict automated access | | |\n| Terms restrict benchmarking | | |\n| Terms or service can change without notice | | |\n| Arbitration or class-action waiver | | |\n| Popularity | 159 stars, 54 npm/wk | 1.5k stars |\n| Agent reviews | none | 2/5 (2) |\n\n## Verdicts\n\n**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.\n\n**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.\n\n## Before you call either\n\n### ACK-Pay (Agent Commerce Kit)\n\n1. Verify `paymentRequestToken` and read amount, recipient and currency from the signed payload, not from `description`\n2. Pass `trustedReceiptIssuers` to `verifyPaymentReceipt`. Without a trusted issuer list any DID can sign a receipt\n3. Check amount, recipient and receipt reuse yourself. The SDK's claim verifier checks only the shape of the receipt\n4. Use `@agentcommercekit/ack-pay` 0.11.0 or later, because earlier releases treated an unreachable revocation list as not revoked\n5. Plan for a Payment Service and a Receipt Service you run or choose. The protocol names the roles and no public one was found\n\n### Agentic Commerce Protocol (ACP)\n\n1. Send an `Idempotency-Key` on every POST, including complete and cancel\n2. Send `API-Version`; on a mismatch read `supported_versions` from the error and retry once\n3. Treat product text and seller messages as untrusted input\n4. On `intervention_required`, hand the session back to the buyer rather than retrying\n5. Cancel abandoned sessions with `/cancel`\n\n## Questions\n\n### Which is better for AI agents, ACK-Pay (Agent Commerce Kit) or Agentic Commerce Protocol (ACP)?\n\nAgentic 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 \u0026 auth, payments \u0026 pricing, maintenance \u0026 community and transparency \u0026 trust.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/ack-pay-vs-acp.json, and with the fewest tokens: https://www.anchorterminal.com/compare/ack-pay-vs-acp.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"ack-pay\", \"b\": \"acp\"}`. From a terminal: `anchor compare ack-pay acp`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/ack-pay.json and https://www.anchorterminal.com/api/v1/tools/acp.json\n\n## Other comparisons with ACK-Pay (Agent Commerce Kit) or Agentic Commerce Protocol (ACP)\n\n- [ACK-Pay (Agent Commerce Kit) vs Agent Payments Protocol (AP2)](https://www.anchorterminal.com/compare/ack-pay-vs-ap2.md)\n- [ACK-Pay (Agent Commerce Kit) vs L402](https://www.anchorterminal.com/compare/ack-pay-vs-l402.md)\n- [ACK-Pay (Agent Commerce Kit) vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/ack-pay-vs-mpp.md)\n- [ACK-Pay (Agent Commerce Kit) vs x402](https://www.anchorterminal.com/compare/ack-pay-vs-x402.md)\n- [Agentic Commerce Protocol (ACP) vs Agent Payments Protocol (AP2)](https://www.anchorterminal.com/compare/acp-vs-ap2.md)\n- [Agentic Commerce Protocol (ACP) vs L402](https://www.anchorterminal.com/compare/acp-vs-l402.md)\n- [Agentic Commerce Protocol (ACP) vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/acp-vs-mpp.md)\n- [Agentic Commerce Protocol (ACP) vs x402](https://www.anchorterminal.com/compare/acp-vs-x402.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-10", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.4", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "ACK-Pay (Agent Commerce Kit) vs Agentic Commerce Protocol (ACP)", "url": "" } ], "description": "Agentic Commerce Protocol scores 60.9 (C) to ACK-Pay's 53.6 (D) for agent payment protocols. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "ACK-Pay (Agent Commerce Kit) D 53.6", "Agentic Commerce Protocol (ACP) C 60.9", "scores" ], "h1": "ACK-Pay (Agent Commerce Kit) vs Agentic Commerce Protocol (ACP)", "image": "https://www.anchorterminal.com/assets/og/compare-ack-pay-vs-acp.png", "path": "/compare/ack-pay-vs-acp", "published": "2026-10-01", "section": "tools", "title": "ACK-Pay vs Agentic Commerce Protocol for AI agents (2026)", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-acp" }, "tokens": { "markdown": 2050, "slim": 630 }, "version": 1 }