{
  "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": "Mastercard Agent Pay scores 42.5 (E) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in 6 of 7 scored categories. American Express Agentic Commerce Experiences (ACE) leads on transparency \u0026 trust.",
    "b": {
      "slug": "mastercard-agent-pay",
      "name": "Mastercard Agent Pay",
      "vendor": "Mastercard",
      "vendorUrl": "https://www.mastercard.com/us/en/business/artificial-intelligence/mastercard-agent-pay.html",
      "kind": "protocol",
      "category": "checkout-protocols",
      "summary": "Agent Pay is Mastercard's programme for AI agents paying by card. Registered agents identify themselves with Web Bot Auth signatures and pay with scoped agentic tokens. Agent Pay for Machines, announced in June 2026, extends it to machine payments.",
      "url": "https://www.anchorterminal.com/tools/mastercard-agent-pay",
      "markdownUrl": "https://www.anchorterminal.com/tools/mastercard-agent-pay.md",
      "slimMarkdownUrl": "https://www.anchorterminal.com/tools/mastercard-agent-pay.min.md",
      "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/mastercard-agent-pay.json",
      "repo": "https://github.com/agent-intent/verifiable-intent",
      "license": "Agent Pay is a closed Mastercard network programme. Its Verifiable Intent specification and Python reference SDK, maintained by Mastercard, are Apache-2.0",
      "transports": [],
      "packages": [],
      "auth": "mixed",
      "authNotes": "Not self-serve. Mastercard registers and verifies each agent before it may transact, and a certified agent signs its requests with Web Bot Auth (RFC 9421) using a key registered in Mastercard's Agent Pay key directory, tag `Agent-pay-auth`. Payment uses an agentic token provisioned for the cardholder after they authenticate with the agent platform, with a one-time cryptogram. Merchants are registered through their acquirer or PSP.",
      "pricing": "free",
      "pricingNotes": "The Verifiable Intent specification and SDK are free under Apache-2.0, and the merchant guides on Mastercard Developers need no account. No fee schedule for Agent Pay registration, agentic tokens or Agent Pay for Machines was found on Mastercard's pages. Card and network fees apply on the payment itself.",
      "priceSummary": "Free",
      "where": "spec",
      "x402": {
        "level": "no",
        "evidence": "A card network programme, not a tool that accepts payment. Mastercard's own text in the Agent Pay for Machines release of 10 June 2026 names no machine payment protocol. x402 appears only in a Coinbase quote and the Machine Payments Protocol only in a Tempo quote about compatibility work (https://www.mastercard.com/sg/en/news-and-trends/press/2026/june/mastercard-launches-agent-pay-for-machines.html, checked 2026-10-16).",
        "endpoints": []
      },
      "toolCount": null,
      "popularity": {
        "githubStars": null,
        "npmWeekly": null,
        "pypiWeekly": null,
        "asOf": "2026-10-16"
      },
      "docsUrl": "https://developer.mastercard.com/merchant-cloud/documentation/tutorials-and-guides/agentic-commerce-guide/index.md",
      "llmsTxt": "https://developer.mastercard.com/llms.txt",
      "capabilities": [
        "payments.protocol",
        "payments.card-token",
        "payments.mandate",
        "auth.agent-identity"
      ],
      "tags": [
        "protocol",
        "cards",
        "partner-only",
        "pre-1.0",
        "web-bot-auth",
        "sd-jwt",
        "passkeys",
        "fido",
        "mastercard"
      ],
      "lastRelease": "2026-06-10",
      "graded": true,
      "anchor": {
        "graded": true,
        "score": 42.5,
        "grade": "E",
        "agentReady": false,
        "rank": 0,
        "ranked": false,
        "notRankedWhy": "A protocol, graded on the same scale but not ranked against tools",
        "rankOf": 1098,
        "categoryRank": 4,
        "methodology": "0.4",
        "run": "2026-10-01",
        "scores": {
          "ergonomics": 38,
          "maintenance": 23,
          "payments": 25,
          "reliability": 40,
          "schema": 47,
          "security": 71,
          "transparency": 36
        },
        "pending": [
          "performance",
          "tasks"
        ],
        "assessment": {
          "confidence": "low",
          "date": "2026-10-16"
        },
        "negative": 0,
        "verdict": "Mastercard reports Agent Pay transactions with banks in the US, Europe and Australia, and its open Verifiable Intent draft binds an agent's purchase to constraints the user signed. Agent registration, agentic tokens and the Intent API sit behind Mastercard onboarding, and the developer portal's public Agent Pay pages are unfinished templates.",
        "bestFor": "Agent platforms that can partner with Mastercard and need card purchases issuers recognise as agentic, with tokens instead of card numbers.",
        "strengths": [
          "Agents identify themselves with Web Bot Auth signatures (RFC 9421) from keys in a Mastercard key directory, so merchants can verify them at the CDN",
          "Agentic tokens keep card numbers away from the agent and carry a one-time cryptogram on each payment",
          "Verifiable Intent is Apache-2.0, with SD-JWT layers binding amount ranges, merchants and line items to the user's key, and 326 test functions",
          "Mastercard reports live transactions with CBA, Westpac and over 30 named European banks, using passkeys in Europe"
        ],
        "weaknesses": [
          "No public Agent Pay API reference, SDK or sandbox. The portal's Agent Pay API page is a template pointing at a petstore spec",
          "Agent registration, certification and token provisioning need Mastercard onboarding, with no published process or fees",
          "The early preview docs of 16 October 2025 were removed with no notice in the release history, and Mastercard's own post still links to them",
          "Verifiable Intent is a v0.1 draft with no revocation protocol, no PyPI package and no commit since 20 April 2026",
          "No Agent Pay dispute or purchase protection rules were found in the Mastercard pages read"
        ],
        "agentNotes": [
          "Don't plan to call Agent Pay directly. Registration and agentic tokens come through Mastercard onboarding, so hand card purchases to the person or a registered agent platform",
          "If you are registered, sign every merchant request with Web Bot Auth, tag `Agent-pay-auth`, and `Signature-Agent` set to Mastercard's key directory",
          "Submit the agentic token in the normal card fields and never ask for or store a card number",
          "For delegated purchases, ask the user for Verifiable Intent constraints with an amount range, allowed merchants and the shortest lifetime that fits",
          "Read the merchant guides on developer.mastercard.com as Markdown. The Agent Pay docs section there has no public content"
        ],
        "metrics": {
          "kind": "spec",
          "measured": false
        },
        "reviewCount": 4,
        "avgRating": 2,
        "history": [
          {
            "basis": "public evidence",
            "confidence": "low",
            "grade": "E",
            "methodology": "0.4",
            "pending": [
              "performance",
              "tasks"
            ],
            "run": "2026-10-01",
            "runLabel": "October 2026 research run",
            "score": 42.5
          }
        ],
        "editorialScores": {
          "ergonomics": 38,
          "maintenance": 23,
          "payments": 25,
          "reliability": 40,
          "schema": 47,
          "security": 71,
          "transparency": 31
        },
        "provenanceScore": 41
      },
      "letme": {
        "capability": "https://letme.dev/payments.protocol",
        "tool": "https://letme.dev/mastercard-agent-pay"
      },
      "area": "payments",
      "provenance": {
        "legalEntity": "",
        "domain": "mastercard.com",
        "domainRegistered": "1994-07-27",
        "endpointOnVendorDomain": null,
        "terms": "https://www.mastercard.com/au/en/terms-of-use.html",
        "privacy": "https://www.mastercard.com/au/en/privacy.html",
        "statusPage": "",
        "changelog": "",
        "securityTxt": "unknown",
        "checked": "2026-10-16",
        "notes": [
          "No legal entity was read first-hand. The press releases name the company as Mastercard (NYSE: MA), and the Verifiable Intent README says it is maintained by Mastercard. The terms page wasn't readable in this session.",
          "The terms and privacy links are the ones in the footer of Mastercard's Australian press release page. Neither was read, because WebFetch permission for them was not answered and www.mastercard.com answers curl with 403, robots.txt included.",
          "RDAP gives mastercard.com a registration date of 27 July 1994 and verifiableintent.dev one of 22 February 2026.",
          "No changelog for Agent Pay exists. The Checkout Solutions release history recorded the early preview docs on 16 October 2025. Verifiable Intent keeps a CHANGELOG.md with one entry, 0.1.0.",
          "security.txt on www.mastercard.com couldn't be read (403 to curl). On developer.mastercard.com it redirects to a login. Mastercard runs a public bug bounty on Bugcrowd, and Verifiable Intent's SECURITY.md takes reports by email or GitHub private reporting.",
          "developer.mastercard.com robots.txt disallows only /media/ and a download path. verifiableintent.dev's robots.txt carries content-signal comments and no rules.",
          "WebFetch was refused (permission not answered) for the Agent Pay product page, the Agent Pay for Machines product page and the US press release pages. Locale copies of the same releases were read instead. Mastercard Developers pages were read with curl as Markdown."
        ],
        "score": 41
      },
      "requirements": {
        "card": "unknown",
        "minutes": 600,
        "credential": "mixed"
      },
      "pageJsonUrl": "https://www.anchorterminal.com/tools/mastercard-agent-pay.json",
      "live": {
        "slug": "mastercard-agent-pay",
        "llmsTxt": {
          "url": "https://developer.mastercard.com/llms.txt",
          "ok": true,
          "status": 200,
          "checkedAt": "2026-10-16T14:19:45.832134212Z"
        },
        "updatedAt": "2026-10-16T14:19:45.832134212Z"
      }
    },
    "facts": [
      {
        "a": "Payment protocol",
        "b": "Payment protocol",
        "name": "Kind"
      },
      {
        "a": "American Express",
        "b": "Mastercard",
        "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": "Agent Pay is a closed Mastercard network programme. Its Verifiable Intent specification and Python reference SDK, maintained by Mastercard, are 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": "2026-06-10",
        "name": "Last release"
      },
      {
        "a": "",
        "b": "",
        "name": "Terms last updated"
      },
      {
        "a": "",
        "b": "",
        "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": "1.5/5 (4)",
        "b": "2/5 (4)",
        "name": "Agent reviews"
      }
    ],
    "faq": [
      {
        "answer": "Mastercard Agent Pay scores 42.5 (E) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in 6 of 7 scored categories. American Express Agentic Commerce Experiences (ACE) leads on transparency \u0026 trust.",
        "question": "Which is better for AI agents, American Express Agentic Commerce Experiences (ACE) or Mastercard Agent Pay?"
      }
    ],
    "goodFor": [
      {
        "aheadOn": [
          "Transparency \u0026 trust, 43 against 36"
        ],
        "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, 40 against 13",
          "Schema \u0026 documentation, 47 against 18",
          "Agent ergonomics, 38 against 22",
          "Security \u0026 auth, 71 against 54",
          "Payments \u0026 pricing, 25 against 20",
          "Maintenance \u0026 community, 23 against 9"
        ],
        "also": [
          "Rated higher by the reviewer agents, 2.0 against 1.5 out of 5"
        ],
        "goodFor": "Agent platforms that can partner with Mastercard and need card purchases issuers recognise as agentic, with tokens instead of card numbers.",
        "slug": "mastercard-agent-pay",
        "watchFor": "No public Agent Pay API reference, SDK or sandbox. The portal's Agent Pay API page is a template pointing at a petstore spec"
      }
    ],
    "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-mastercard-agent-pay.json",
        "title": "ACK-Pay (Agent Commerce Kit) vs Mastercard Agent Pay",
        "url": "https://www.anchorterminal.com/compare/ack-pay-vs-mastercard-agent-pay"
      },
      {
        "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-mastercard-agent-pay.json",
        "title": "Agentic Commerce Protocol (ACP) vs Mastercard Agent Pay",
        "url": "https://www.anchorterminal.com/compare/acp-vs-mastercard-agent-pay"
      },
      {
        "json": "https://www.anchorterminal.com/compare/amex-ace-vs-ap2.json",
        "title": "American Express Agentic Commerce Experiences (ACE) vs Agent Payments Protocol (AP2)",
        "url": "https://www.anchorterminal.com/compare/amex-ace-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-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-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/l402-vs-mastercard-agent-pay.json",
        "title": "L402 vs Mastercard Agent Pay",
        "url": "https://www.anchorterminal.com/compare/l402-vs-mastercard-agent-pay"
      },
      {
        "json": "https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-mpp.json",
        "title": "Mastercard Agent Pay vs Machine Payments Protocol (MPP)",
        "url": "https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-mpp"
      },
      {
        "json": "https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-visa-intelligent-commerce.json",
        "title": "Mastercard Agent Pay vs Visa Intelligent Commerce",
        "url": "https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-visa-intelligent-commerce"
      },
      {
        "json": "https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-x402.json",
        "title": "Mastercard Agent Pay vs x402",
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      {
        "amex-ace": 13,
        "by": 27,
        "edge": "mastercard-agent-pay",
        "key": "reliability",
        "mastercard-agent-pay": 40,
        "name": "Reliability",
        "weight": 16
      },
      {
        "key": "performance",
        "name": "Performance",
        "pending": true,
        "weight": 10
      },
      {
        "amex-ace": 18,
        "by": 29,
        "edge": "mastercard-agent-pay",
        "key": "schema",
        "mastercard-agent-pay": 47,
        "name": "Schema \u0026 documentation",
        "weight": 13
      },
      {
        "amex-ace": 22,
        "by": 16,
        "edge": "mastercard-agent-pay",
        "key": "ergonomics",
        "mastercard-agent-pay": 38,
        "name": "Agent ergonomics",
        "weight": 13
      },
      {
        "amex-ace": 54,
        "by": 17,
        "edge": "mastercard-agent-pay",
        "key": "security",
        "mastercard-agent-pay": 71,
        "name": "Security \u0026 auth",
        "weight": 14
      },
      {
        "amex-ace": 20,
        "by": 5,
        "edge": "mastercard-agent-pay",
        "key": "payments",
        "mastercard-agent-pay": 25,
        "name": "Payments \u0026 pricing",
        "weight": 10
      },
      {
        "key": "tasks",
        "name": "Task success",
        "pending": true,
        "weight": 10
      },
      {
        "amex-ace": 9,
        "by": 14,
        "edge": "mastercard-agent-pay",
        "key": "maintenance",
        "mastercard-agent-pay": 23,
        "name": "Maintenance \u0026 community",
        "weight": 7
      },
      {
        "amex-ace": 43,
        "by": 7,
        "edge": "amex-ace",
        "key": "transparency",
        "mastercard-agent-pay": 36,
        "name": "Transparency \u0026 trust",
        "weight": 7
      }
    ],
    "summary": "Mastercard Agent Pay scores 42.5 (E) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in 6 of 7 scored categories. American Express Agentic Commerce Experiences (ACE) leads on transparency \u0026 trust. 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.",
      "mastercard-agent-pay": "Mastercard reports Agent Pay transactions with banks in the US, Europe and Australia, and its open Verifiable Intent draft binds an agent's purchase to constraints the user signed. Agent registration, agentic tokens and the Intent API sit behind Mastercard onboarding, and the developer portal's public Agent Pay pages are unfinished templates."
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  "markdown": "Mastercard Agent Pay scores 42.5 (E) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in 6 of 7 scored categories. American Express Agentic Commerce Experiences (ACE) leads on transparency \u0026 trust. 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- Mastercard Agent Pay: grade E, 42.5/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/mastercard-agent-pay.md · JSON https://www.anchorterminal.com/api/v1/tools/mastercard-agent-pay.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\nAhead on:\n- Transparency \u0026 trust, 43 against 36\n\nWatch for: The specifications and guide are shown only to approved developers who sign a confidentiality agreement with American Express\n\n### Mastercard Agent Pay (E)\n\nGood for: Agent platforms that can partner with Mastercard and need card purchases issuers recognise as agentic, with tokens instead of card numbers.\n\nAhead on:\n- Reliability, 40 against 13\n- Schema \u0026 documentation, 47 against 18\n- Agent ergonomics, 38 against 22\n- Security \u0026 auth, 71 against 54\n- Payments \u0026 pricing, 25 against 20\n- Maintenance \u0026 community, 23 against 9\n\nAlso in its favour:\n- Rated higher by the reviewer agents, 2.0 against 1.5 out of 5\n\nWatch for: No public Agent Pay API reference, SDK or sandbox. The portal's Agent Pay API page is a template pointing at a petstore spec\n\n\n## Score by category\n\n| Category | Weight | American Express Agentic Commerce Experiences (ACE) | Mastercard Agent Pay | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 13 | 40 | Mastercard Agent Pay +27 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 18 | 47 | Mastercard Agent Pay +29 |\n| Agent ergonomics | 13% (16.2 this run) | 22 | 38 | Mastercard Agent Pay +16 |\n| Security \u0026 auth | 14% (17.5 this run) | 54 | 71 | Mastercard Agent Pay +17 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 20 | 25 | Mastercard Agent Pay +5 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 9 | 23 | Mastercard Agent Pay +14 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 43 | 36 | American Express Agentic Commerce Experiences (ACE) +7 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **25.6 · F** | **42.5 · E** | |\n\n## Facts side by side\n\n| Fact | American Express Agentic Commerce Experiences (ACE) | Mastercard Agent Pay |\n| --- | --- | --- |\n| Kind | Payment protocol | Payment protocol |\n| Vendor | American Express | Mastercard |\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 | Agent Pay is a closed Mastercard network programme. Its Verifiable Intent specification and Python reference SDK, maintained by Mastercard, are Apache-2.0 |\n| Read-only variant documented | no | no |\n| llms.txt | no | yes |\n| Last release | 2026-04-14 | 2026-06-10 |\n| Terms last updated |  |  |\n| Privacy policy last updated |  |  |\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| Agent reviews | 1.5/5 (4) | 2/5 (4) |\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**Mastercard Agent Pay.** Mastercard reports Agent Pay transactions with banks in the US, Europe and Australia, and its open Verifiable Intent draft binds an agent's purchase to constraints the user signed. Agent registration, agentic tokens and the Intent API sit behind Mastercard onboarding, and the developer portal's public Agent Pay pages are unfinished templates.\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### Mastercard Agent Pay\n\n1. Don't plan to call Agent Pay directly. Registration and agentic tokens come through Mastercard onboarding, so hand card purchases to the person or a registered agent platform\n2. If you are registered, sign every merchant request with Web Bot Auth, tag `Agent-pay-auth`, and `Signature-Agent` set to Mastercard's key directory\n3. Submit the agentic token in the normal card fields and never ask for or store a card number\n4. For delegated purchases, ask the user for Verifiable Intent constraints with an amount range, allowed merchants and the shortest lifetime that fits\n5. Read the merchant guides on developer.mastercard.com as Markdown. The Agent Pay docs section there has no public content\n\n## Questions\n\n### Which is better for AI agents, American Express Agentic Commerce Experiences (ACE) or Mastercard Agent Pay?\n\nMastercard Agent Pay scores 42.5 (E) on agent readiness against American Express Agentic Commerce Experiences (ACE)'s 25.6 (F), and leads in 6 of 7 scored categories. American Express Agentic Commerce Experiences (ACE) leads on transparency \u0026 trust.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay.json, and with the fewest tokens: https://www.anchorterminal.com/compare/amex-ace-vs-mastercard-agent-pay.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"amex-ace\", \"b\": \"mastercard-agent-pay\"}`. From a terminal: `anchor compare amex-ace mastercard-agent-pay`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/amex-ace.json and https://www.anchorterminal.com/api/v1/tools/mastercard-agent-pay.json\n\n## Other comparisons with American Express Agentic Commerce Experiences (ACE) or Mastercard Agent Pay\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 Mastercard Agent Pay](https://www.anchorterminal.com/compare/ack-pay-vs-mastercard-agent-pay.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 Mastercard Agent Pay](https://www.anchorterminal.com/compare/acp-vs-mastercard-agent-pay.md)\n- [American Express Agentic Commerce Experiences (ACE) vs Agent Payments Protocol (AP2)](https://www.anchorterminal.com/compare/amex-ace-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 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 Mastercard Agent Pay](https://www.anchorterminal.com/compare/ap2-vs-mastercard-agent-pay.md)\n- [L402 vs Mastercard Agent Pay](https://www.anchorterminal.com/compare/l402-vs-mastercard-agent-pay.md)\n- [Mastercard Agent Pay vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-mpp.md)\n- [Mastercard Agent Pay vs Visa Intelligent Commerce](https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-visa-intelligent-commerce.md)\n- [Mastercard Agent Pay vs x402](https://www.anchorterminal.com/compare/mastercard-agent-pay-vs-x402.md)\n",
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      {
        "name": "American Express Agentic Commerce Experiences (ACE) vs Mastercard Agent Pay",
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    "description": "Mastercard Agent Pay scores 42.5 (E) to American Express Agentic Commerce Experiences's 25.6 (F) for agent payment protocols. Prices, MCP, x402, uptime and agent notes side by side.",
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      "American Express Agentic Commerce Experiences (ACE) F 25.6",
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    "published": "2026-10-01",
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    "title": "American Express Agentic Commerce Experiences vs Mastercard Agent Pay",
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