{ "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": "Agent Payments Protocol (AP2) scores 55.3 (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 reliability, payments \u0026 pricing and maintenance \u0026 community.", "b": { "slug": "ap2", "name": "Agent Payments Protocol (AP2)", "vendor": "Google (standardisation moved to the FIDO Alliance)", "vendorUrl": "https://ap2-protocol.org", "kind": "protocol", "category": "checkout-protocols", "summary": "Google's protocol for authorising agent payments, now governed by the FIDO Alliance.", "url": "https://www.anchorterminal.com/tools/ap2", "markdownUrl": "https://www.anchorterminal.com/tools/ap2.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/ap2.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/ap2.json", "repo": "https://github.com/google-agentic-commerce/AP2", "license": "Apache-2.0", "transports": [], "packages": [], "auth": "mixed", "authNotes": "Needs a credentials provider and a mandate signed by the user in advance. Not account-free.", "pricing": "free", "pricingNotes": "No fees defined. Card and network fees apply on the payment itself.", "priceSummary": "Free", "where": "spec", "x402": { "level": "no", "evidence": "A payment protocol, not a tool that accepts payment.", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 3200, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-09-26" }, "docsUrl": "https://ap2-protocol.org", "llmsTxt": "https://ap2-protocol.org/llms.txt", "capabilities": [ "payments.protocol", "payments.mandate" ], "tags": [ "protocol", "pre-1.0", "mandates", "fido" ], "lastRelease": "2026-04-28", "graded": true, "anchor": { "graded": true, "score": 55.3, "grade": "C", "agentReady": false, "rank": 0, "ranked": false, "notRankedWhy": "A protocol, graded on the same scale but not ranked against tools", "rankOf": 950, "categoryRank": 2, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 51, "maintenance": 19, "payments": 60, "reliability": 31, "schema": 74, "security": 84, "transparency": 56 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "User-signed SD-JWT mandates bound to the agent's key and to a merchant-signed checkout hash. No production deployment named by Google or found elsewhere.", "bestFor": "The design to copy when an agent spends a person's money and you need signed proof of what they approved, especially for purchases made while the person is away.", "strengths": [ "User-signed SD-JWT mandates bound to the agent's key and to a merchant-signed checkout hash", "Open mandates cap amount range, total budget, recurrence, merchants and items", "Threat model treats every LLM as a potential attacker and bounds the damage at verification", "Signed receipts to the agent, credential provider and network, usable as dispute evidence", "Standardisation now at FIDO, with Mastercard and Visa chairing the payments working group" ], "weaknesses": [ "No production deployment named by Google or found elsewhere", "No commit on main since 29 April 2026, with 50 open issues and 69 open pull requests", "The v0.1 spec page is still live and contradicts v0.2", "Python SDK only, installed from git, and no conformance vectors", "No documented way to revoke an open mandate before it expires" ], "agentNotes": [ "Read /ap2/specification/ for v0.2; /specification/ is the old v0.1 text", "Ask the user for open mandates with the shortest expiry that fits the task and a budget constraint", "Don't present a second open mandate until you hold a rejection receipt for the first", "Present only the disclosures the verifier needs", "Install the SDK from git; there is no PyPI package" ], "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": 55.3 } ], "editorialScores": { "ergonomics": 51, "maintenance": 19, "payments": 60, "reliability": 31, "schema": 74, "security": 84, "transparency": 55 }, "provenanceScore": 57 }, "letme": { "capability": "https://letme.dev/payments.protocol", "tool": "https://letme.dev/ap2" }, "area": "payments", "provenance": { "legalEntity": "Google LLC", "domain": "ap2-protocol.org", "domainRegistered": "2025-09-15", "domainNote": "The site and repository carry a Google copyright and SECURITY.md routes reports to Google. The FIDO Alliance took on standardisation in April 2026 but doesn't publish the spec yet.", "endpointOnVendorDomain": null, "terms": "", "privacy": "", "statusPage": "", "changelog": "https://github.com/google-agentic-commerce/AP2/blob/main/CHANGELOG.md", "securityTxt": "none", "checked": "2026-10-01", "score": 57 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/ap2.json", "live": { "slug": "ap2", "versions": [ { "registry": "github", "name": "google-agentic-commerce/AP2", "version": "v0.2.0", "released": "2026-04-28", "seenAt": "2026-10-09T16:39:42.488913375Z" } ], "githubStars": 3214, "securityTxt": { "url": "https://ap2-protocol.org/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-09T15:39:17.147165617Z" }, "llmsTxt": { "url": "https://ap2-protocol.org/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-09T14:01:25.733104434Z" }, "domain": { "domain": "ap2-protocol.org", "registered": "2025-09-15", "source": "https://rdap.publicinterestregistry.org/rdap/domain/ap2-protocol.org", "checkedAt": "2026-10-04T13:10:46.099796965Z" }, "pages": [ { "url": "https://raw.githubusercontent.com/google-agentic-commerce/AP2/main/CHANGELOG.md", "kind": "changelog", "status": 304, "checkedAt": "2026-10-09T18:45:17.161366987Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "4e99eb9a25b1" } ], "updatedAt": "2026-10-09T18:45:17.161366987Z" } }, "facts": [ { "a": "Payment protocol", "b": "Payment protocol", "name": "Kind" }, { "a": "Catena Labs, Inc.", "b": "Google (standardisation moved to the FIDO Alliance)", "name": "Vendor" }, { "a": "no (local only)", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "", "b": "", "name": "Transports" }, { "a": "None", "b": "OAuth or 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": "yes", "name": "llms.txt" }, { "a": "2026-08-04", "b": "2026-04-28", "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": "3.2k stars", "name": "Popularity" }, { "a": "none", "b": "2/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "Agent Payments Protocol (AP2) scores 55.3 (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 reliability, payments \u0026 pricing and maintenance \u0026 community.", "question": "Which is better for AI agents, ACK-Pay (Agent Commerce Kit) or Agent Payments Protocol (AP2)?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 38 against 31", "Payments \u0026 pricing, 77 against 60", "Maintenance \u0026 community, 53 against 19" ], "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": [ "Schema \u0026 documentation, 74 against 66", "Security \u0026 auth, 84 against 58" ], "also": null, "goodFor": "The design to copy when an agent spends a person's money and you need signed proof of what they approved, especially for purchases made while the person is away.", "slug": "ap2", "watchFor": "No production deployment named by Google or found elsewhere" } ], "job": { "capability": "payments.protocol", "name": "Agent payment protocols" }, "others": [ { "json": "https://www.anchorterminal.com/compare/ack-pay-vs-acp.json", "title": "ACK-Pay (Agent Commerce Kit) vs Agentic Commerce Protocol (ACP)", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-acp" }, { "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/ap2-vs-l402.json", "title": "Agent Payments Protocol (AP2) vs L402", "url": "https://www.anchorterminal.com/compare/ap2-vs-l402" }, { "json": "https://www.anchorterminal.com/compare/ap2-vs-mpp.json", "title": "Agent Payments Protocol (AP2) vs Machine Payments Protocol (MPP)", "url": "https://www.anchorterminal.com/compare/ap2-vs-mpp" }, { "json": "https://www.anchorterminal.com/compare/ap2-vs-x402.json", "title": "Agent Payments Protocol (AP2) vs x402", "url": "https://www.anchorterminal.com/compare/ap2-vs-x402" } ], "scores": [ { "ack-pay": 38, "ap2": 31, "by": 7, "edge": "ack-pay", "key": "reliability", "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "ack-pay": 66, "ap2": 74, "by": 8, "edge": "ap2", "key": "schema", "name": "Schema \u0026 documentation", "weight": 13 }, { "ack-pay": 47, "ap2": 51, "by": 4, "edge": "ap2", "key": "ergonomics", "name": "Agent ergonomics", "weight": 13 }, { "ack-pay": 58, "ap2": 84, "by": 26, "edge": "ap2", "key": "security", "name": "Security \u0026 auth", "weight": 14 }, { "ack-pay": 77, "ap2": 60, "by": 17, "edge": "ack-pay", "key": "payments", "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "ack-pay": 53, "ap2": 19, "by": 34, "edge": "ack-pay", "key": "maintenance", "name": "Maintenance \u0026 community", "weight": 7 }, { "ack-pay": 60, "ap2": 56, "by": 4, "edge": "ack-pay", "key": "transparency", "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "Agent Payments Protocol (AP2) scores 55.3 (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 reliability, payments \u0026 pricing and maintenance \u0026 community. 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.", "ap2": "User-signed SD-JWT mandates bound to the agent's key and to a merchant-signed checkout hash. No production deployment named by Google or found elsewhere." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/ack-pay-vs-ap2", "json": "https://www.anchorterminal.com/compare/ack-pay-vs-ap2.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/ack-pay-vs-ap2.md", "slim": "https://www.anchorterminal.com/compare/ack-pay-vs-ap2.min.md" }, "markdown": "Agent Payments Protocol (AP2) scores 55.3 (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 reliability, payments \u0026 pricing and maintenance \u0026 community. 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- Agent Payments Protocol (AP2): grade C, 55.3/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/ap2.md · JSON https://www.anchorterminal.com/api/v1/tools/ap2.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- Reliability, 38 against 31\n- Payments \u0026 pricing, 77 against 60\n- Maintenance \u0026 community, 53 against 19\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### Agent Payments Protocol (AP2) (C)\n\nGood for: The design to copy when an agent spends a person's money and you need signed proof of what they approved, especially for purchases made while the person is away.\n\nAhead on:\n- Schema \u0026 documentation, 74 against 66\n- Security \u0026 auth, 84 against 58\n\nWatch for: No production deployment named by Google or found elsewhere\n\n\n## Score by category\n\n| Category | Weight | ACK-Pay (Agent Commerce Kit) | Agent Payments Protocol (AP2) | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 38 | 31 | ACK-Pay (Agent Commerce Kit) +7 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 66 | 74 | Agent Payments Protocol (AP2) +8 |\n| Agent ergonomics | 13% (16.2 this run) | 47 | 51 | Agent Payments Protocol (AP2) +4 |\n| Security \u0026 auth | 14% (17.5 this run) | 58 | 84 | Agent Payments Protocol (AP2) +26 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 77 | 60 | ACK-Pay (Agent Commerce Kit) +17 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 53 | 19 | ACK-Pay (Agent Commerce Kit) +34 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 60 | 56 | ACK-Pay (Agent Commerce Kit) +4 |\n| Negative events | ≤15 | -2 | 0 | |\n| **Total** | | **53.6 · D** | **55.3 · C** | |\n\n## Facts side by side\n\n| Fact | ACK-Pay (Agent Commerce Kit) | Agent Payments Protocol (AP2) |\n| --- | --- | --- |\n| Kind | Payment protocol | Payment protocol |\n| Vendor | Catena Labs, Inc. | Google (standardisation moved to the FIDO Alliance) |\n| Hosted endpoint | no (local only) | no (local only) |\n| Transports | | |\n| Auth | None | OAuth or 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 | yes |\n| Last release | 2026-08-04 | 2026-04-28 |\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 | 3.2k 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**Agent Payments Protocol (AP2).** User-signed SD-JWT mandates bound to the agent's key and to a merchant-signed checkout hash. No production deployment named by Google or found elsewhere.\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### Agent Payments Protocol (AP2)\n\n1. Read /ap2/specification/ for v0.2; /specification/ is the old v0.1 text\n2. Ask the user for open mandates with the shortest expiry that fits the task and a budget constraint\n3. Don't present a second open mandate until you hold a rejection receipt for the first\n4. Present only the disclosures the verifier needs\n5. Install the SDK from git; there is no PyPI package\n\n## Questions\n\n### Which is better for AI agents, ACK-Pay (Agent Commerce Kit) or Agent Payments Protocol (AP2)?\n\nAgent Payments Protocol (AP2) scores 55.3 (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 reliability, payments \u0026 pricing and maintenance \u0026 community.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/ack-pay-vs-ap2.json, and with the fewest tokens: https://www.anchorterminal.com/compare/ack-pay-vs-ap2.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"ack-pay\", \"b\": \"ap2\"}`. From a terminal: `anchor compare ack-pay ap2`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/ack-pay.json and https://www.anchorterminal.com/api/v1/tools/ap2.json\n\n## Other comparisons with ACK-Pay (Agent Commerce Kit) or Agent Payments Protocol (AP2)\n\n- [ACK-Pay (Agent Commerce Kit) vs Agentic Commerce Protocol (ACP)](https://www.anchorterminal.com/compare/ack-pay-vs-acp.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- [Agent Payments Protocol (AP2) vs L402](https://www.anchorterminal.com/compare/ap2-vs-l402.md)\n- [Agent Payments Protocol (AP2) vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/ap2-vs-mpp.md)\n- [Agent Payments Protocol (AP2) vs x402](https://www.anchorterminal.com/compare/ap2-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 Agent Payments Protocol (AP2)", "url": "" } ], "description": "Agent Payments Protocol scores 55.3 (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", "Agent Payments Protocol (AP2) C 55.3", "scores" ], "h1": "ACK-Pay (Agent Commerce Kit) vs Agent Payments Protocol (AP2)", "image": "https://www.anchorterminal.com/assets/og/compare-ack-pay-vs-ap2.png", "path": "/compare/ack-pay-vs-ap2", "published": "2026-10-01", "section": "tools", "title": "ACK-Pay vs Agent Payments Protocol for AI agents (2026)", "toc": null, "updated": "2026-10-09", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-ap2" }, "tokens": { "markdown": 2000, "slim": 630 }, "version": 1 }