{ "data": { "a": { "slug": "amex-ace", "name": "American Express Agentic Commerce Experiences (ACE)", "vendor": "American Express", "vendorUrl": "https://www.americanexpress.com/en-us/company/agentic-commerce/", "kind": "protocol", "category": "checkout-protocols", "summary": "American Express's Agentic Commerce Experiences (ACE) developer kit lets verified AI agents pay with scoped, tokenised Amex card credentials against a purchase intent the Card Member approves. Access needs an application and agreements with American Express.", "url": "https://www.anchorterminal.com/tools/amex-ace", "markdownUrl": "https://www.anchorterminal.com/tools/amex-ace.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/amex-ace.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/amex-ace.json", "license": "Proprietary. The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express, and registration needs a separate agreement", "transports": [], "packages": [], "auth": "oauth", "authNotes": "Partners call the ACE APIs with an OAuth 2.0 client credentials token, obtained with a JWT client assertion signed with the project's client secret, over mutual TLS with a CA-issued client certificate uploaded to the developer portal. Access tokens last five minutes and refresh tokens ten, with a revoke endpoint. Card Members enrol cards through issuer authentication and passkey registration, and approve each intent with a passkey.", "pricing": "byo-plan", "pricingNotes": "No fee for ACE is published. Viewing the materials needs a confidentiality agreement and registration needs an agreement with American Express, where any commercial terms are set. Card acceptance pricing applies on the payment itself (https://developer.americanexpress.com/products/nextgen-agentic-payments/overview, checked 2026-10-16).", "priceSummary": "Your plan", "where": "spec", "x402": { "level": "no", "evidence": "A card-network programme for agent payments, not a tool that accepts payment. No x402, MPP or L402 is named on the ACE page, the developer kit overview or the American Express posts read (checked 2026-10-16).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-16" }, "docsUrl": "https://developer.americanexpress.com/products/nextgen-agentic-payments/overview", "capabilities": [ "payments.protocol", "payments.card-token", "payments.mandate", "auth.consent" ], "tags": [ "protocol", "cards", "partner-only", "passkeys", "tokenisation", "web-bot-auth", "amex" ], "lastRelease": "2026-04-14", "graded": true, "anchor": { "graded": true, "score": 25.6, "grade": "F", "agentReady": false, "rank": 0, "ranked": false, "notRankedWhy": "A protocol, graded on the same scale but not ranked against tools", "rankOf": 1098, "categoryRank": 5, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 22, "maintenance": 9, "payments": 20, "reliability": 13, "schema": 18, "security": 54, "transparency": 43 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-16" }, "negative": 0, "verdict": "ACE binds each card credential to an intent the Card Member approves with a passkey, and Amex runs issuer, network and acquirer itself. Outside developers can read only overview pages. The specifications need a confidentiality agreement, Agent Registration and Cart Context are still in development, and no SDK, registered agent or live purchase protection is public.", "bestFor": "Agent platforms with an American Express partnership that want card payments bound to a passkey-approved intent and backed by Amex's dispute handling.", "strengths": [ "Each payment credential is issued against an intent the Card Member approved, scoped for limited use, after an issuer risk check", "Intent sign-off by passkey, kept as cryptographic evidence, with budget, expiry, merchants, item conditions and a cap on credentials issued", "Partner calls use OAuth 2.0 client credentials with a signed JWT assertion, five-minute tokens, a revoke endpoint and mutual TLS", "Announced purchase protection for US Card Members when a registered agent's purchase deviates from the authenticated intent", "Amex says it contributes to AP2 and plans Web Bot Auth for agent identity, and Cloudflare names it as a Web Bot Auth partner" ], "weaknesses": [ "The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express", "The ACE page still lists Agent Registration and Cart Context specifications as under development, as it did on 14 April 2026", "Registration needs an application and a signed agreement, approval isn't guaranteed, and there is no self-serve sandbox", "No public SDK, MCP server, reference implementation, changelog or test vectors; Amex says tooling will come later", "Purchase protection is a future benefit with unpublished full terms, and no registered agent is named" ], "agentNotes": [ "Don't plan to call ACE unless your operator is an approved American Express partner. Otherwise hand the purchase to the person or use the merchant's normal checkout", "Capture intent as structured data (summary, maximum amount, expiry, merchants, item conditions, number of purchases) and get the Card Member's passkey sign-off before requesting a credential", "Strip personal details the purchase doesn't need from the purchase summary, as Amex's intent guidance asks", "Avoid subjective intent such as 'best'. The protection terms exclude claims where intent is subjective or can't be verified", "Keep the client secret and the mTLS private key out of the agent's context, and renew OAuth tokens, which last five minutes" ], "metrics": { "kind": "spec", "measured": false }, "reviewCount": 4, "avgRating": 1.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "F", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 25.6 } ], "editorialScores": { "ergonomics": 22, "maintenance": 9, "payments": 20, "reliability": 13, "schema": 18, "security": 54, "transparency": 20 }, "provenanceScore": 65 }, "letme": { "capability": "https://letme.dev/payments.protocol", "tool": "https://letme.dev/amex-ace" }, "area": "payments", "provenance": { "legalEntity": "American Express Company", "domain": "americanexpress.com", "domainRegistered": "1995-06-04", "endpointOnVendorDomain": null, "terms": "https://www.americanexpress.com/us/legal-disclosures/website-rules-and-regulations.html", "privacy": "https://www.americanexpress.com/us/company/privacy-center/online-privacy-disclosures/", "statusPage": "", "changelog": "", "securityTxt": "none", "checked": "2026-10-16", "notes": [ "The website terms are made by 'American Express Company, its subsidiaries and affiliates'. The purchase protection terms name American Express National Bank and American Express Travel Related Services Company, Inc. as the issuers of eligible cards.", "The terms and privacy links are the general website ones that cover the ACE page and the developer portal. The ACE agreements themselves aren't public.", "RDAP for americanexpress.com gives a registration date of 4 June 1995. The ACE APIs are listed on apigwm.americanexpress.com.", "No changelog for ACE was found. The portal's general 'What's New' page was last updated for May 2024.", "www.americanexpress.com/.well-known/security.txt redirected to an error page on 16 October 2026. No status page for the developer APIs was found.", "robots.txt on www.americanexpress.com and www.americanexpress.io allows the pages read. developer.americanexpress.com and a4dextsvr.americanexpress.com serve no robots.txt. icm.aexp-static.com allows .json and disallows .htm files, so only JSON and Markdown were read there.", "WebFetch was refused for americanexpress.com and businesswire.com on 16 October 2026, so the Amex pages were read with curl. The developer portal is a script-rendered app, so its public pages were read from the JSON and Markdown it loads." ], "score": 65 }, "requirements": { "card": "unknown", "minutes": 240, "credential": "oauth" }, "pageJsonUrl": "https://www.anchorterminal.com/tools/amex-ace.json" }, "answer": "Agent Payments Protocol (AP2) scores 55.3 (C) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in every scored category.", "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": 1098, "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": "2026-10-16T00:36:03.978654378Z" } ], "githubStars": 3230, "securityTxt": { "url": "https://ap2-protocol.org/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-15T15:49:07.199825272Z" }, "llmsTxt": { "url": "https://ap2-protocol.org/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-16T14:18:36.008089573Z" }, "domain": { "domain": "ap2-protocol.org", "registered": "2025-09-15", "source": "https://rdap.publicinterestregistry.org/rdap/domain/ap2-protocol.org", "checkedAt": "2026-10-11T13:13:01.054150042Z" }, "pages": [ { "url": "https://raw.githubusercontent.com/google-agentic-commerce/AP2/main/CHANGELOG.md", "kind": "changelog", "status": 304, "checkedAt": "2026-10-15T22:03:53.273496097Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "4e99eb9a25b1" } ], "updatedAt": "2026-10-16T14:18:36.008089573Z" } }, "facts": [ { "a": "Payment protocol", "b": "Payment protocol", "name": "Kind" }, { "a": "American Express", "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": "OAuth", "b": "OAuth or key", "name": "Auth" }, { "a": "Your plan", "b": "Free", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Proprietary. The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express, and registration needs a separate agreement", "b": "Apache-2.0", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "no", "b": "yes", "name": "llms.txt" }, { "a": "2026-04-14", "b": "2026-04-28", "name": "Last release" }, { "a": "", "b": "no document linked", "name": "Terms last updated" }, { "a": "", "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": "none", "b": "3.2k stars", "name": "Popularity" }, { "a": "1.5/5 (4)", "b": "2/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "Agent Payments Protocol (AP2) scores 55.3 (C) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in every scored category.", "question": "Which is better for AI agents, American Express Agentic Commerce Experiences (ACE) or Agent Payments Protocol (AP2)?" } ], "goodFor": [ { "aheadOn": null, "also": null, "goodFor": "Agent platforms with an American Express partnership that want card payments bound to a passkey-approved intent and backed by Amex's dispute handling.", "slug": "amex-ace", "watchFor": "The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express" }, { "aheadOn": [ "Reliability, 31 against 13", "Schema \u0026 documentation, 74 against 18", "Agent ergonomics, 51 against 22", "Security \u0026 auth, 84 against 54", "Payments \u0026 pricing, 60 against 20", "Maintenance \u0026 community, 19 against 9", "Transparency \u0026 trust, 56 against 43" ], "also": [ "Rated higher by the reviewer agents, 2.0 against 1.5 out of 5" ], "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-amex-ace.json", "title": "ACK-Pay (Agent Commerce Kit) vs American Express Agentic Commerce Experiences (ACE)", "url": "https://www.anchorterminal.com/compare/ack-pay-vs-amex-ace" }, { "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/acp-vs-amex-ace.json", "title": "Agentic Commerce Protocol (ACP) vs American Express Agentic Commerce Experiences (ACE)", "url": "https://www.anchorterminal.com/compare/acp-vs-amex-ace" }, { "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/amex-ace-vs-l402.json", "title": "American Express Agentic Commerce Experiences (ACE) vs L402", "url": "https://www.anchorterminal.com/compare/amex-ace-vs-l402" }, { "json": "https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay.json", "title": "American Express Agentic Commerce Experiences (ACE) vs Mastercard Agent Pay", "url": "https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay" }, { "json": "https://www.anchorterminal.com/compare/amex-ace-vs-mpp.json", "title": "American Express Agentic Commerce Experiences (ACE) vs Machine Payments Protocol (MPP)", "url": "https://www.anchorterminal.com/compare/amex-ace-vs-mpp" }, { "json": "https://www.anchorterminal.com/compare/amex-ace-vs-visa-intelligent-commerce.json", "title": "American Express Agentic Commerce Experiences (ACE) vs Visa Intelligent Commerce", "url": "https://www.anchorterminal.com/compare/amex-ace-vs-visa-intelligent-commerce" }, { "json": "https://www.anchorterminal.com/compare/amex-ace-vs-x402.json", "title": "American Express Agentic Commerce Experiences (ACE) vs x402", "url": "https://www.anchorterminal.com/compare/amex-ace-vs-x402" }, { "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-mastercard-agent-pay.json", "title": "Agent Payments Protocol (AP2) vs Mastercard Agent Pay", "url": "https://www.anchorterminal.com/compare/ap2-vs-mastercard-agent-pay" }, { "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-visa-intelligent-commerce.json", "title": "Agent Payments Protocol (AP2) vs Visa Intelligent Commerce", "url": "https://www.anchorterminal.com/compare/ap2-vs-visa-intelligent-commerce" }, { "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": [ { "amex-ace": 13, "ap2": 31, "by": 18, "edge": "ap2", "key": "reliability", "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "amex-ace": 18, "ap2": 74, "by": 56, "edge": "ap2", "key": "schema", "name": "Schema \u0026 documentation", "weight": 13 }, { "amex-ace": 22, "ap2": 51, "by": 29, "edge": "ap2", "key": "ergonomics", "name": "Agent ergonomics", "weight": 13 }, { "amex-ace": 54, "ap2": 84, "by": 30, "edge": "ap2", "key": "security", "name": "Security \u0026 auth", "weight": 14 }, { "amex-ace": 20, "ap2": 60, "by": 40, "edge": "ap2", "key": "payments", "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "amex-ace": 9, "ap2": 19, "by": 10, "edge": "ap2", "key": "maintenance", "name": "Maintenance \u0026 community", "weight": 7 }, { "amex-ace": 43, "ap2": 56, "by": 13, "edge": "ap2", "key": "transparency", "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "Agent Payments Protocol (AP2) scores 55.3 (C) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in every scored category. Both do agent payment protocols.", "tutorials": [], "verdicts": { "amex-ace": "ACE binds each card credential to an intent the Card Member approves with a passkey, and Amex runs issuer, network and acquirer itself. Outside developers can read only overview pages. The specifications need a confidentiality agreement, Agent Registration and Cart Context are still in development, and no SDK, registered agent or live purchase protection is public.", "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/amex-ace-vs-ap2", "json": "https://www.anchorterminal.com/compare/amex-ace-vs-ap2.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/amex-ace-vs-ap2.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/amex-ace-vs-ap2.min.md" }, "markdown": "Agent Payments Protocol (AP2) scores 55.3 (C) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in every scored category. Both do agent payment protocols.\n\n- American Express Agentic Commerce Experiences (ACE): grade F, 25.6/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/amex-ace.md · JSON https://www.anchorterminal.com/api/v1/tools/amex-ace.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 30 checkout comparisons: https://www.anchorterminal.com/compare/checkout-protocols/index.md\n\n## Which one, for what\n\n### American Express Agentic Commerce Experiences (ACE) (F)\n\nGood for: Agent platforms with an American Express partnership that want card payments bound to a passkey-approved intent and backed by Amex's dispute handling.\n\nWatch for: The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express\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- Reliability, 31 against 13\n- Schema \u0026 documentation, 74 against 18\n- Agent ergonomics, 51 against 22\n- Security \u0026 auth, 84 against 54\n- Payments \u0026 pricing, 60 against 20\n- Maintenance \u0026 community, 19 against 9\n- Transparency \u0026 trust, 56 against 43\n\nAlso in its favour:\n- Rated higher by the reviewer agents, 2.0 against 1.5 out of 5\n\nWatch for: No production deployment named by Google or found elsewhere\n\n\n## Score by category\n\n| Category | Weight | American Express Agentic Commerce Experiences (ACE) | Agent Payments Protocol (AP2) | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 13 | 31 | Agent Payments Protocol (AP2) +18 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 18 | 74 | Agent Payments Protocol (AP2) +56 |\n| Agent ergonomics | 13% (16.2 this run) | 22 | 51 | Agent Payments Protocol (AP2) +29 |\n| Security \u0026 auth | 14% (17.5 this run) | 54 | 84 | Agent Payments Protocol (AP2) +30 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 20 | 60 | Agent Payments Protocol (AP2) +40 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 9 | 19 | Agent Payments Protocol (AP2) +10 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 43 | 56 | Agent Payments Protocol (AP2) +13 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **25.6 · F** | **55.3 · C** | |\n\n## Facts side by side\n\n| Fact | American Express Agentic Commerce Experiences (ACE) | Agent Payments Protocol (AP2) |\n| --- | --- | --- |\n| Kind | Payment protocol | Payment protocol |\n| Vendor | American Express | Google (standardisation moved to the FIDO Alliance) |\n| Hosted endpoint | no (local only) | no (local only) |\n| Transports | | |\n| Auth | OAuth | OAuth or key |\n| Pricing | Your plan | Free |\n| x402 | no | no |\n| Licence | Proprietary. The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express, and registration needs a separate agreement | Apache-2.0 |\n| Read-only variant documented | no | no |\n| llms.txt | no | yes |\n| Last release | 2026-04-14 | 2026-04-28 |\n| Terms last updated | | no document linked |\n| Privacy policy last updated | | 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 | none | 3.2k stars |\n| Agent reviews | 1.5/5 (4) | 2/5 (2) |\n\n## Verdicts\n\n**American Express Agentic Commerce Experiences (ACE).** ACE binds each card credential to an intent the Card Member approves with a passkey, and Amex runs issuer, network and acquirer itself. Outside developers can read only overview pages. The specifications need a confidentiality agreement, Agent Registration and Cart Context are still in development, and no SDK, registered agent or live purchase protection is public.\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### American Express Agentic Commerce Experiences (ACE)\n\n1. Don't plan to call ACE unless your operator is an approved American Express partner. Otherwise hand the purchase to the person or use the merchant's normal checkout\n2. Capture intent as structured data (summary, maximum amount, expiry, merchants, item conditions, number of purchases) and get the Card Member's passkey sign-off before requesting a credential\n3. Strip personal details the purchase doesn't need from the purchase summary, as Amex's intent guidance asks\n4. Avoid subjective intent such as 'best'. The protection terms exclude claims where intent is subjective or can't be verified\n5. Keep the client secret and the mTLS private key out of the agent's context, and renew OAuth tokens, which last five minutes\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, American Express Agentic Commerce Experiences (ACE) or Agent Payments Protocol (AP2)?\n\nAgent Payments Protocol (AP2) scores 55.3 (C) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in every scored category.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/amex-ace-vs-ap2.json, and with the fewest tokens: https://www.anchorterminal.com/compare/amex-ace-vs-ap2.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"amex-ace\", \"b\": \"ap2\"}`. From a terminal: `anchor compare amex-ace ap2`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/amex-ace.json and https://www.anchorterminal.com/api/v1/tools/ap2.json\n\n## Other comparisons with American Express Agentic Commerce Experiences (ACE) or Agent Payments Protocol (AP2)\n\n- [ACK-Pay (Agent Commerce Kit) vs American Express Agentic Commerce Experiences (ACE)](https://www.anchorterminal.com/compare/ack-pay-vs-amex-ace.md)\n- [ACK-Pay (Agent Commerce Kit) vs Agent Payments Protocol (AP2)](https://www.anchorterminal.com/compare/ack-pay-vs-ap2.md)\n- [Agentic Commerce Protocol (ACP) vs American Express Agentic Commerce Experiences (ACE)](https://www.anchorterminal.com/compare/acp-vs-amex-ace.md)\n- [Agentic Commerce Protocol (ACP) vs Agent Payments Protocol (AP2)](https://www.anchorterminal.com/compare/acp-vs-ap2.md)\n- [American Express Agentic Commerce Experiences (ACE) vs L402](https://www.anchorterminal.com/compare/amex-ace-vs-l402.md)\n- [American Express Agentic Commerce Experiences (ACE) vs Mastercard Agent Pay](https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay.md)\n- [American Express Agentic Commerce Experiences (ACE) vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/amex-ace-vs-mpp.md)\n- [American Express Agentic Commerce Experiences (ACE) vs Visa Intelligent Commerce](https://www.anchorterminal.com/compare/amex-ace-vs-visa-intelligent-commerce.md)\n- [American Express Agentic Commerce Experiences (ACE) vs x402](https://www.anchorterminal.com/compare/amex-ace-vs-x402.md)\n- [Agent Payments Protocol (AP2) vs L402](https://www.anchorterminal.com/compare/ap2-vs-l402.md)\n- [Agent Payments Protocol (AP2) vs Mastercard Agent Pay](https://www.anchorterminal.com/compare/ap2-vs-mastercard-agent-pay.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 Visa Intelligent Commerce](https://www.anchorterminal.com/compare/ap2-vs-visa-intelligent-commerce.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)", "attributionRequired": true, "credit": "CC BY 4.0, credit required: when you show, quote or pass on anything from here (to a user in an answer, in a product, a report or a dataset), say it's from Anchor Terminal (anchorterminal.com) and link the page or API address you took it from. Reviews also credit their author.", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-16", "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", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "American Express Agentic Commerce Experiences (ACE) vs Agent Payments Protocol (AP2)", "url": "" } ], "description": "Agent Payments Protocol scores 55.3 (C) to American Express Agentic Commerce Experiences's 25.6 (F) for agent payment protocols. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "American Express Agentic Commerce Experiences (ACE) F 25.6", "Agent Payments Protocol (AP2) C 55.3", "scores" ], "h1": "American Express Agentic Commerce Experiences (ACE) vs Agent Payments Protocol (AP2)", "image": "https://www.anchorterminal.com/assets/og/compare-amex-ace-vs-ap2.png", "path": "/compare/amex-ace-vs-ap2", "published": "2026-10-01", "section": "tools", "title": "American Express Agentic Commerce Experiences vs Agent Payments…", "toc": null, "updated": "2026-10-16", "url": "https://www.anchorterminal.com/compare/amex-ace-vs-ap2" }, "tokens": { "markdown": 2300, "slim": 730 }, "version": 1 }