{"generatedAt":"2026-09-24T04:37:57.908Z","counts":{"protocols":13,"protocolsPublished":10,"deployments":12,"changelog":9},"protocols":[{"slug":"x402","name":"x402","fullName":"x402 Payment Protocol","layer":"payment-execution","category":"onchain","status":"live","createdBy":["Coinbase"],"launched":"2025-05","rails":["USDC","Base","Solana","stablecoins"],"settlement":"On-chain stablecoin (USDC) settled via facilitators.","reversible":false,"humanInLoop":"none","d2cFit":"moderate","b2bFit":"strong","specUrl":"https://www.x402.org/","summary":"Revives the dormant HTTP 402 status code: a server answers a request with 402 and machine-readable payment requirements, the agent signs and pays in stablecoin, a facilitator verifies and settles on-chain, and the request is retried with a payment header. Governance transferred to the vendor-neutral x402 Foundation under the Linux Foundation in 2026, with 40 founding members including Visa, Mastercard, Stripe, Adyen, and AWS.","howItWorks":"x402 turns the long-unused **HTTP 402 \"Payment Required\"** status into a working payment handshake between clients and servers, with no accounts or API keys.\n\n1. **Challenge.** A client requests a protected resource. Instead of `200`, the server returns **`402`** with a machine-readable body describing what is owed — amount, asset (typically USDC), destination, network, and an expiry.\n2. **Pay.** The client (an agent's wallet) constructs and **signs a payment payload** authorizing the transfer, and retries the request with the signed payload attached in an `X-PAYMENT` header.\n3. **Verify & settle.** The server hands the payload to a **facilitator** — a pluggable service that verifies the signature and settles the transfer on-chain. Merchants can use a hosted facilitator or self-host their own.\n4. **Fulfil.** Once settlement is confirmed, the server returns the resource (`200`) along with a settlement receipt.\n\nBecause settlement rides on stablecoin rails, payments are **push-based and final**. The design contemplates **deferred/batched settlement** so that many sub-cent calls can be aggregated rather than settled individually, mitigating per-transaction gas overhead.\n\n**Protocol V2** (mid-2026) introduced CAIP-2 network identifiers, scoped `@x402/*` npm packages, new header names (`PAYMENT-REQUIRED`, `PAYMENT-SIGNATURE`, `PAYMENT-RESPONSE`), a Bazaar discovery extension, and support for `exact`, `upto`, and `batch-settlement` payment schemes. Coinbase contributed the protocol to the **Linux Foundation** in April 2026; the x402 Foundation became operationally active in July 2026 with 40 members spanning payments incumbents (Visa, Mastercard, Amex, Adyen, Fiserv, Stripe), cloud providers (AWS, Google, Cloudflare), and blockchain ecosystems.","tradeoffs":["Payments are non-reversible: there is no built-in chargeback, dispute, or refund mechanism, so error handling and trust must be solved out-of-band.","Latency is bounded by on-chain confirmation, which is slower than an authorize-now/capture-later card flow.","Sub-cent, per-call pricing runs into gas economics unless calls are batched or deferred.","Custody shifts to the agent: the paying party must hold and manage keys (MPC wallets or scoped session keys), expanding the attack surface."],"securityNotes":["Documented attack classes include unpaid-service and paid-but-denied failures, where either side of the exchange defaults after the other performs.","Payment metadata (resource URL, description, reason) can travel in plaintext, creating PII-leakage and transaction-linkability risk.","Prompt-injection against the paying agent can induce fraudulent or over-value payments, since the agent both decides and authorizes.","Replay and overpayment drain are concerns without strict nonce/expiry handling and per-request payment caps."],"interopsWith":["stripe-mpp","erc-4337"],"sources":[{"title":"x402 — official protocol site","url":"https://www.x402.org/","publisher":"x402 Foundation"},{"title":"x402 documentation (Welcome)","url":"https://docs.cdp.coinbase.com/x402/docs/welcome","publisher":"Coinbase Developer Platform"},{"title":"x402 Foundation — reference implementation (post-contribution)","url":"https://github.com/x402-foundation/x402","publisher":"x402 Foundation (GitHub)"},{"title":"Linux Foundation Announces Operational Launch of x402 Foundation","url":"https://www.linuxfoundation.org/press/linux-foundation-announces-operational-launch-of-x402-foundation-to-standardize-internet-native-payments-for-ai-agents-and-applications","publisher":"Linux Foundation","date":"2026-07-14"},{"title":"Linux Foundation is Launching the x402 Foundation (initial announcement)","url":"https://www.linuxfoundation.org/press/linux-foundation-is-launching-the-x402-foundation-and-welcoming-the-contribution-of-the-x402-protocol","publisher":"Linux Foundation","date":"2026-04-02"},{"title":"Migration Guide: V1 to V2","url":"https://docs.x402.org/guides/migration-v1-to-v2","publisher":"x402 Foundation"}],"lastVerified":"2026-09-03"},{"slug":"a2a","name":"A2A","fullName":"Agent2Agent (A2A) Protocol","layer":"agent-communication","category":"framework","status":"live","createdBy":["Google"],"launched":"2025-04","rails":[],"settlement":"","reversible":null,"humanInLoop":"n/a","d2cFit":"n/a","b2bFit":"n/a","specUrl":"https://a2a-protocol.org/latest/","summary":"An open interoperability layer for agent-to-agent communication: it lets independent agents discover each other, exchange capabilities, and coordinate tasks. It is not a payment-execution protocol itself — payments ride on top via other protocols.","howItWorks":"A2A is a **communication and interoperability standard**, not a payment rail. Its purpose is to let agents built by different vendors, on different frameworks, **discover one another and collaborate** on tasks.\n\n- **Agent Cards.** Each agent publishes a machine-readable descriptor advertising its identity, skills, and endpoints, so a client agent can find and evaluate a remote agent.\n- **Tasks & messages.** A client agent opens a task with a remote agent and they exchange structured messages and artifacts until the task completes, supporting long-running and streaming interactions.\n- **Transport.** It layers on ordinary web primitives (HTTP, JSON-RPC/SSE), which keeps it framework-agnostic and easy to adopt alongside existing services.\n\nThe most common point of confusion is treating A2A as a way to *pay* agents. It is not: A2A carries the **coordination**, and value transfer is delegated to a dedicated payment or authorization layer (for example AP2 for mandates, or an execution protocol such as x402). Keeping this distinction explicit is essential when reading the comparison matrix — the settlement and reversibility columns are marked not-applicable for A2A on purpose.","tradeoffs":["Carries no payment semantics: any monetary exchange must be delegated to a separate authorization/execution protocol.","Interoperability depends on both agents adopting the same version and honoring published Agent Card capabilities.","As a coordination layer, it inherits the trust and identity problems of whichever agents connect through it."],"securityNotes":["Agent discovery and capability advertisement widen the surface for impersonation and capability spoofing without strong agent identity.","Because tasks can be long-running and delegated, injection or manipulation mid-task can propagate to downstream systems the agent can reach."],"interopsWith":["ap2","x402"],"sources":[{"title":"A2A Protocol — documentation","url":"https://a2a-protocol.org/latest/","publisher":"A2A Project"},{"title":"A2A: A new era of agent interoperability","url":"https://developers.googleblog.com/en/a2a-a-new-era-of-agent-interoperability/","publisher":"Google Developers Blog","date":"2025-04"},{"title":"A2A specification and reference material","url":"https://github.com/a2aproject/A2A","publisher":"A2A Project (GitHub)"}],"lastVerified":"2026-09-02"},{"slug":"ap2","name":"AP2","fullName":"Agent Payments Protocol (AP2)","layer":"payment-authorization","category":"framework","status":"live","createdBy":["Google"],"launched":"2025-09","rails":[],"settlement":"Delegates settlement to underlying payment rails; AP2 governs authorization.","reversible":null,"humanInLoop":"optional","d2cFit":"strong","b2bFit":"moderate","specUrl":"https://github.com/google-agentic-commerce/AP2","summary":"An authorization and governance framework for agent-initiated payments. It defines verifiable mandates that capture user intent and constraints, so an agent can transact on a user's behalf with an auditable chain of consent. Complements A2A and is rail-agnostic. Google donated AP2 to the FIDO Alliance in April 2026; v0.2 added Human-Not-Present autonomous transaction flows.","howItWorks":"AP2 addresses the **\"was this payment actually authorized?\"** problem for agent commerce. It does not move money itself; it standardizes **verifiable mandates** that prove a payment was consented to and bounded.\n\n**v0.2** (April 2026) reorganized the mandate model from three types (Intent, Cart, Payment) into two — **Checkout Mandate** and **Payment Mandate** — each of which can be **Open** (pre-authorized constraints) or **Closed** (bound to a specific transaction). This gives Human-Not-Present flows a structured authorization model: users define bounded authority in advance, agents act without per-step approval, and merchants receive verifiable evidence that the transaction stayed within the granted authority.\n\n- **Open Checkout / Payment Mandates.** Capture what the agent is allowed to buy and spend within user-defined limits.\n- **Closed Checkout / Payment Mandates.** Signed by the authorized agent after confirming the transaction matches the user's constraints, producing a cryptographic link between authorization, checkout, and payment.\n- **Receipts.** Checkout and Payment Receipts provide post-transaction evidence for audit and dispute.\n\n**Verifiable Intent**, co-developed with Mastercard and also donated to FIDO, complements AP2 by creating tamper-proof, portable evidence of user authorization that issuers, networks, and merchants can independently validate.\n\nGoogle donated AP2 and Verifiable Intent to the **FIDO Alliance** in April 2026. The core specification is now developed within FIDO's Payments Technical Working Group and Agentic Authentication Technical Working Group; the GitHub repository hosts SDKs and samples only. AP2 is deliberately **rail-agnostic**: it sits above card networks, bank transfers, and stablecoin execution protocols.","tradeoffs":["It authorizes but does not settle: an execution rail (card network, bank, or an on-chain protocol) is still required to move funds.","Value depends on ecosystem adoption by credential providers and merchants to honor the mandates.","As an evolving specification under FIDO governance, mandate formats and flows may change; integrations should track versioning.","Human-Not-Present flows concentrate risk: pre-set limits and revocation must be enforced reliably, and mandate replay or manipulation could lead to unauthorized spending."],"securityNotes":["The security model rests on the integrity of mandate issuance and verification; weak key management for mandates undermines the entire consent chain.","Delegated (Human-Not-Present) mandates concentrate risk into pre-set limits and revocation, which must be enforced reliably.","A systematic security analysis (arXiv 2608.23858, Aug 2026) found that valid mandate signatures alone do not ensure a transaction reflects user intent when the pre-authorization context is manipulated."],"interopsWith":["a2a","x402"],"sources":[{"title":"Powering AI commerce with the new Agent Payments Protocol (AP2)","url":"https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol","publisher":"Google Cloud","date":"2025-09-16"},{"title":"AP2 SDKs and samples (spec donated to FIDO)","url":"https://github.com/google-agentic-commerce/AP2","publisher":"Google Agentic Commerce (GitHub)"},{"title":"Google donates Agent Payments Protocol to FIDO Alliance (v0.2 announcement)","url":"https://blog.google/products-and-platforms/platforms/google-pay/agent-payments-protocol-fido-alliance/","publisher":"Google","date":"2026-04-28"},{"title":"Building the Trust Layer for Agentic Payments with AP2 and Verifiable Intent","url":"https://fidoalliance.org/building-the-trust-layer-for-agentic-payments-with-ap2-and-verifiable-intent/","publisher":"FIDO Alliance"}],"lastVerified":"2026-09-03"},{"slug":"stripe-mpp","name":"MPP","fullName":"Machine Payments Protocol (MPP)","layer":"payment-execution","category":"hybrid","status":"beta","createdBy":["Stripe","Tempo"],"launched":"2026-03","rails":["cards","stablecoins","USDC"],"settlement":"Settles through Stripe (PaymentIntents), across card and stablecoin rails; stablecoin settlement via the Tempo blockchain.","reversible":true,"humanInLoop":"optional","d2cFit":"moderate","b2bFit":"strong","specUrl":"https://mpp.dev","summary":"An open, internet-native protocol for machine and agent payments, co-authored by Stripe and Tempo. Spans both card (via Shared Payment Tokens) and stablecoin rails, settling through Stripe's existing infrastructure. The spec is open at mpp.dev; Stripe acceptance is in early access as of September 2026.","howItWorks":"MPP is an **open standard** co-authored by Stripe and Tempo that lets **agents pay for APIs and services programmatically** without a checkout UI.\n\n- **402 challenge flow.** When an agent requests a resource, the service returns an HTTP `402` response with payment details. The agent authorizes the payment, retries the request, and receives the resource with a receipt.\n- **Rail coverage.** MPP spans **card and stablecoin rails**. Cards are handled via **Shared Payment Tokens (SPTs)** — scoped grants that let an agent use a customer's payment method with usage and expiration limits. Stablecoin payments settle via the **Tempo** blockchain. Stripe's machine-payments surface also supports **x402** for stablecoin-only flows.\n- **Payment shapes.** Covers **one-shot, recurring, and streaming** payments, so an agent can pay once or maintain ongoing/metered obligations.\n- **Settlement.** Flows settle through **Stripe PaymentIntents**, which means agent payments reuse Stripe's reconciliation, reporting, and (for card rails) dispute handling.\n\nThe specification is open at **mpp.dev**. Stripe acceptance remains in **early access**; dynamic pricing for MPP is on Stripe's public preview roadmap. This entry is marked **beta** accordingly.","tradeoffs":["Reversibility is mixed: card-rail payments retain dispute/refund rights, but stablecoin settlement does not — a single 'reversible' flag over-simplifies, so confirm per rail.","Settling through Stripe implies operating within Stripe's account, availability, and compliance model rather than a permissionless one.","As an early-access surface, capabilities and interfaces may shift; integrations should track Stripe's changelog."],"securityNotes":["Agent-initiated recurring/streaming payments require robust scoping and revocation to prevent runaway or manipulated charges.","Where MPP bridges to stablecoin/x402 flows, the non-reversibility and custody considerations of on-chain settlement apply to that leg.","Shared Payment Tokens carry scoped card access; token leakage or insufficient scope constraints could enable unauthorized charges."],"interopsWith":["x402"],"sources":[{"title":"Machine payments — Overview","url":"https://docs.stripe.com/payments/machine","publisher":"Stripe"},{"title":"MPP payments — Machine Payments Protocol","url":"https://docs.stripe.com/payments/machine/mpp","publisher":"Stripe"},{"title":"Introducing the Machine Payments Protocol","url":"https://stripe.com/blog/machine-payments-protocol","publisher":"Stripe","date":"2026-03"},{"title":"MPP specification","url":"https://mpp.dev","publisher":"MPP (Stripe & Tempo)"}],"lastVerified":"2026-09-03"},{"slug":"erc-4337","name":"ERC-4337","fullName":"ERC-4337 Account Abstraction","layer":"wallet-custody","category":"primitive","status":"live","createdBy":["Vitalik Buterin","Yoav Weiss","eth-infinitism"],"launched":"2023-03","rails":[],"settlement":"","reversible":null,"humanInLoop":"n/a","d2cFit":"n/a","b2bFit":"n/a","specUrl":"https://eips.ethereum.org/EIPS/eip-4337","summary":"An account-abstraction standard that enables programmable smart-contract wallets on Ethereum without consensus-layer changes. It is a supporting custody primitive for agent payments — session keys, spending limits, gas abstraction — not a payment protocol in its own right.","howItWorks":"ERC-4337 brings **account abstraction** to Ethereum entirely at the application layer, with no changes to the consensus protocol. Instead of an externally-owned account (EOA) signing a native transaction, a user (or agent) expresses intent as a **`UserOperation`** pseudo-transaction.\n\n- **Separate mempool.** `UserOperation` objects are broadcast to a dedicated mempool, not the normal transaction pool.\n- **Bundlers.** A class of actors called **bundlers** collect `UserOperation`s and package them into a single `handleOps` call to a singleton **EntryPoint** contract, which runs a verification loop then an execution loop.\n- **Smart accounts.** Each account implements `validateUserOp`, so validation logic is fully programmable — passkeys, multisig, social recovery, session keys, and per-operation spending limits.\n- **Paymasters.** An optional **paymaster** (`validatePaymasterUserOp`) can sponsor gas or let a user pay gas in an ERC-20, and `initCode` deploys the account on first use.\n\nFor this registry, ERC-4337 matters as **custody infrastructure**: it is how an agent can hold funds and sign payments under tightly-scoped, revocable authority (for example paying an x402 endpoint from a session-keyed smart account) rather than a rail that itself moves value.","tradeoffs":["It is account infrastructure, not a payment protocol: value transfer still happens over a separate rail built on top of it.","Added complexity and gas overhead versus a plain EOA, and reliance on off-chain bundler and paymaster infrastructure.","Accounts must trust a specific singleton EntryPoint contract; trusting the wrong EntryPoint is a risk.","The EIP is formally still Standards-Track \"Draft\" and has shipped in versioned revisions (v0.6, v0.7) whose interfaces differ, so implementations must pin a version."],"securityNotes":["Custody safety depends on the correctness of each account's validateUserOp logic; a bug there is a direct loss-of-funds risk.","Bundler/paymaster griefing and denial vectors are constrained by staking and validation rules (ERC-7562), which implementations must honor.","Session keys and delegated spending limits must be scoped and revocable, or a compromised agent can drain within its allowance."],"interopsWith":["x402"],"sources":[{"title":"ERC-4337: Account Abstraction Using Alt Mempool (specification)","url":"https://eips.ethereum.org/EIPS/eip-4337","publisher":"Ethereum Improvement Proposals"},{"title":"eth-infinitism/account-abstraction (reference implementation)","url":"https://github.com/eth-infinitism/account-abstraction","publisher":"eth-infinitism (GitHub)"},{"title":"ERC-4337 Documentation","url":"https://docs.erc4337.io/","publisher":"erc4337.io"}],"lastVerified":"2026-09-02"},{"slug":"p3p","name":"P3P","fullName":"Pine Labs Payment Protocol (P3P)","layer":"payment-execution","category":"hybrid","status":"live","createdBy":["Pine Labs"],"launched":"2026-06","rails":["UPI"],"settlement":"Settles through UPI's existing mandate infrastructure (Single Block Multiple Debit / Reserve Pay and One Time Mandate).","reversible":true,"humanInLoop":"optional","d2cFit":"strong","b2bFit":"moderate","specUrl":"https://www.pinelabs.com/media-analyst/the-ai-agent-can-now-pay-pine-labs-launches-p3p-indias-first-agentic-payment-protocol-built-on-upi","summary":"India's first agentic payment protocol on UPI. Extends UPI's mandate framework so an AI agent can complete a payment after a single upfront user authorization, with no per-transaction human authentication. Combines UPI mandate rails, an HTTP 402 discovery layer, and the Grantex identity/audit layer.","howItWorks":"P3P enables AI agents to complete UPI payments **without per-transaction human authentication** — a gap that previously blocked every agent at UPI's MPIN/PIN step.\n\n- **One-time mandate.** The consumer authorizes a UPI mandate once (Single Block Multiple Debit or One Time Mandate). After that, the agent can browse, select, negotiate, and pay within the mandate's bounds.\n- **HTTP 402 discovery.** P3P uses the **HTTP 402** standard for machine-readable payment requests, providing a standardized protocol for agents to discover and request payment from merchants.\n- **Grantex identity layer.** A separate platform that provides verifiable agent identity, delegated authorization, spend controls, and a full audit trail. The consumer can set spending limits and revoke or update the mandate at any time.\n- **Settlement.** Payments settle through UPI's existing infrastructure, using proven mandate mechanisms (SBMD / Reserve Pay for blocked funds, OTM for one-time authorizations) with near-instant settlement.\n\nP3P is **live in production** with Gullak (digital gold savings). Vijay Sales (electronics retail) is in proof of concept. Pine Labs is working with major card networks to extend the mandate-based authorization to card transactions.","tradeoffs":["Currently limited to UPI rails in India; card network extension is planned but not yet live.","Relies on UPI mandate infrastructure, which has issuer-specific limits (as reported, banks cap Reserve Pay at ₹10,000 for up to 90 days).","Regulatory questions remain open: how P3P interacts with RBI's Additional Factor of Authentication requirements for each UPI payment.","Grantex identity layer is proprietary to Pine Labs, creating potential platform lock-in."],"securityNotes":["The mandate-based model shifts the security boundary from per-transaction PIN to a one-time authorization, so mandate hijacking or scope manipulation is the primary attack vector.","Consumer control depends on the reliability of mandate revocation and Grantex's enforcement of spend limits.","Agent identity is delegated through Grantex; compromise of the identity layer could enable unauthorized agents to spend within mandate bounds."],"interopsWith":[],"sources":[{"title":"The AI Agent Can Now Pay. Pine Labs Launches P3P — India's First Agentic Payment Protocol Built on UPI","url":"https://www.pinelabs.com/media-analyst/the-ai-agent-can-now-pay-pine-labs-launches-p3p-indias-first-agentic-payment-protocol-built-on-upi","publisher":"Pine Labs","date":"2026-06-11"},{"title":"Pine Labs launches P3P agentic payment protocol on UPI","url":"https://thepaypers.com/payments/news/pine-labs-launches-p3p-agentic-payment-protocol-on-upi","publisher":"The Paypers","date":"2026-06"}],"lastVerified":"2026-09-03"},{"slug":"visa-tap","name":"TAP","fullName":"Visa Trusted Agent Protocol (TAP)","layer":"payment-authorization","category":"card-rail","status":"live","createdBy":["Visa","Cloudflare"],"launched":"2025-10","rails":["cards"],"settlement":"Delegates settlement to Visa's existing card network; TAP governs agent identity verification and authorization.","reversible":null,"humanInLoop":"optional","d2cFit":"strong","b2bFit":"moderate","specUrl":"https://developer.visa.com/capabilities/trusted-agent-protocol/docs","summary":"A cryptographic trust framework for agentic commerce on the Visa network. Uses RFC 9421 HTTP Message Signatures so a Visa-approved AI agent can prove its identity, consumer authorization, and payment credentials to merchants — letting merchants distinguish legitimate buying agents from bots. Live in Europe with 30+ issuers since July 2026.","howItWorks":"TAP addresses a specific merchant-side problem: **how does a website know the automated visitor at checkout is a legitimate agent, not a scraper or carding bot?**\n\n- **Cryptographic signatures.** A Visa-approved agent signs every HTTP request with a private key using **RFC 9421 HTTP Message Signatures** (Ed25519 or RSA-PSS-SHA256). The signature covers timestamps, a nonce, a key identifier, and a tag indicating the action (browsing or payment), so the merchant can verify that the request is current and not replayed.\n- **Three-signature model.** TAP defines three layered signatures: (1) **Agent Intent** — proves the agent is registered and has a commerce purpose; (2) **Consumer Recognition** — passes verifiable consumer identifiers so the merchant can recognise returning customers; (3) **Payment Information** — carries Payment Account References (PARs) or other credentials to streamline checkout.\n- **Agent Directory.** Merchants verify agent public keys against Visa's Agent Directory. Cloudflare and Akamai embed TAP verification into their edge networks, so merchants behind those CDNs can adopt TAP with no new infrastructure.\n- **Issuer authentication.** On the issuer side, Visa Payment Passkeys authenticate agent-initiated transactions and support European Strong Customer Authentication (SCA) requirements.\n\nTAP is deliberately **not a settlement rail** — it layers trust and identity on top of Visa's existing card network. It complements execution protocols like x402 by solving the \"who is this agent?\" question that x402's HTTP 402 flow does not address.","tradeoffs":["Tied to the Visa network: merchants and agents must operate within Visa's credentialing and directory ecosystem.","Requires agent registration with Visa, which creates a centralised trust anchor rather than a permissionless identity model.","Adoption depends on CDN and acquirer integration; merchants not behind Cloudflare or Akamai need custom implementation.","The protocol governs identity and authorization only — settlement, pricing, and dispute handling remain on Visa's existing card rails."],"securityNotes":["Security rests on the integrity of the agent's private key and Visa's Agent Directory; compromise of either undermines the trust chain.","The three-signature model binds agent identity to consumer credentials and payment data via a shared nonce — a nonce mismatch invalidates the binding even if individual signatures verify.","As with any centralised directory model, the Agent Directory is a single point of failure for trust verification."],"interopsWith":["x402"],"sources":[{"title":"Visa Introduces Trusted Agent Protocol: An Ecosystem-Led Framework for AI Commerce","url":"https://usa.visa.com/about-visa/newsroom/press-releases.releaseId.21716.html","publisher":"Visa","date":"2025-10-14"},{"title":"Getting Started with Visa's Trusted Agent Protocol","url":"https://developer.visa.com/capabilities/trusted-agent-protocol/docs","publisher":"Visa Developer Center"},{"title":"Visa Trusted Agent Protocol — reference implementation and samples","url":"https://github.com/visa/trusted-agent-protocol","publisher":"Visa (GitHub)"},{"title":"Visa and Banks Across Europe Reach the Next Phase of Agentic Commerce","url":"https://www.visa.co.uk/about-visa/newsroom/press-releases.3457328.html","publisher":"Visa","date":"2026-07-02"}],"lastVerified":"2026-09-14"},{"slug":"mc-ap4m","name":"AP4M","fullName":"Mastercard Agent Pay for Machines (AP4M)","layer":"payment-execution","category":"card-rail","status":"live","createdBy":["Mastercard"],"launched":"2026-06","rails":["cards","bank accounts","stablecoins"],"settlement":"Multi-rail settlement across cards, bank accounts, and stablecoins via Mastercard's global network.","reversible":true,"humanInLoop":"optional","d2cFit":"moderate","b2bFit":"strong","specUrl":"https://www.mastercard.com/us/en/news-and-trends/press/2026/june/mastercard-launches-agent-pay-for-machines.html","summary":"A Mastercard network service for high-frequency, low-latency machine-to-machine payments. Builds on the Agent Pay program (2025) with credentialing via Verifiable Intent, programmable permissioning, and multi-rail settlement. Launched June 2026 with 30+ partners including Stripe, Adyen, Coinbase, and Cloudflare.","howItWorks":"AP4M extends Mastercard's **Agent Pay** program (2025) from human-delegated agent transactions to **fully autonomous machine-to-machine commerce** — payments that run continuously in the background with no human in the transaction loop.\n\n- **Credentialing.** Every agent is credentialed on Mastercard's network. **Verifiable Intent** (co-developed with Google and donated to FIDO alongside AP2) provides a tamper-proof record of what the agent is authorized to do, so counterparties can cryptographically verify an agent's identity and mandate.\n- **Permissioning.** Organizations set authorization rules and spending limits that are **programmatically enforced** — per-transaction caps, per-period budgets, and allowed merchant categories — ensuring transactions stay within defined parameters without per-transaction human approval.\n- **Transacting.** Verified agents connect and transact across providers and systems, enabling continuous, high-frequency automated commerce. Mastercard's network handles routing and orchestration at machine speed.\n- **Settling.** Multi-rail settlement supports **cards, bank accounts, and stablecoins**. Recipients receive payouts in their preferred currency, and the settlement layer provides the guarantee and finality that machine-speed commerce requires.\n\nAP4M is positioned for use cases like an AI agent autonomously purchasing compute, hosting, and checkout infrastructure, or a logistics agent paying freight and monitoring fees — transactions that are high-frequency, low-value, and fully automated.","tradeoffs":["Operates within Mastercard's centralised network and credentialing model, which is a trust advantage for regulated commerce but limits permissionless participation.","Primary Mastercard documentation URLs return 403 to automated fetchers; details here are verified against the investor relations announcement and third-party coverage.","As a newly launched service (June 2026), production-scale transaction volumes and edge cases are still being validated with the 30+ launch partners.","Multi-rail settlement (cards + accounts + stablecoins) adds flexibility but also complexity in reconciliation and dispute handling across different rails."],"securityNotes":["Agent credentialing and Verifiable Intent are load-bearing trust primitives; a compromised credential could authorize unauthorized machine-speed spending.","Programmatic spending limits must be enforced atomically and in real time to prevent race conditions or burst-spending exploits at machine speed.","The multi-rail settlement model means security properties differ per rail — card disputes, bank reversals, and stablecoin finality each have different risk profiles."],"interopsWith":["ap2","x402"],"sources":[{"title":"Mastercard launches AP4M for AI-led transactions","url":"https://www.electronicpaymentsinternational.com/news/mastercard-launches-ap4m-for-ai-led-transactions/","publisher":"Electronic Payments International","date":"2026-06-11"},{"title":"Mastercard launches Agent Connect for agentic commerce","url":"https://thepaypers.com/payments/news/mastercard-launches-agent-connect-for-agentic-commerce","publisher":"The Paypers","date":"2026-09-10"}],"lastVerified":"2026-09-14"},{"slug":"a402","name":"a402","fullName":"A402 (Atomic Service Channels)","layer":"payment-execution","category":"onchain","status":"proposed","createdBy":["Li et al. (academic research)"],"rails":["Ethereum","Bitcoin"],"settlement":"Off-chain Atomic Service Channels, aggregated and settled on-chain via a TEE-based liquidity vault.","reversible":false,"humanInLoop":"none","d2cFit":"weak","b2bFit":"moderate","specUrl":"https://arxiv.org/abs/2603.01179","summary":"A research-stage payment architecture (arXiv, Mar 2026) that binds crypto payments to verifiable service execution for machine-to-machine commerce. It is positioned explicitly as addressing x402's lack of end-to-end atomicity across execution, payment, and delivery.","howItWorks":"A402 is a **trust-minimized payment architecture** proposed to fix a specific gap the authors identify in x402: x402 sequences payment, service execution, and response delivery through a facilitator but does **not enforce end-to-end atomicity** across the three.\n\n- **Atomic Service Channels (ASCs).** A402 extends payment channels so that each payment is explicitly bound to a service request and its result delivery, offloading on-chain payments into off-chain channels for real-time, high-frequency micropayments.\n- **Exec–Pay–Deliver invariant.** Within an ASC, an atomic exchange protocol built on **TEE-assisted adaptor signatures** guarantees a payment is finalized *if and only if* the request is correctly executed and the result is delivered.\n- **TEE Liquidity Vault.** A trusted-execution-environment vault privately manages ASC lifecycles and aggregates many settlements into a single on-chain transaction that reveals only aggregated balances.\n\nThe authors report an implementation evaluated against x402 on both Bitcoin and Ethereum, claiming order-of-magnitude performance and on-chain-cost improvements. This entry is marked **proposed**: it is a published research design, not a production deployment, and its claims should be read as the paper's rather than as settled ecosystem fact.","tradeoffs":["Research-stage: a published architecture with a prototype, not a production system with real deployments.","Security guarantees depend on trusted execution environments (TEEs) and remote attestation — a hardware-trust assumption x402 does not require.","Meaningfully more complex than a plain HTTP-402 flow, trading simplicity for atomicity and privacy.","Reported performance and cost advantages are the authors' own measurements and are not yet independently corroborated at scale."],"securityNotes":["The Exec–Pay–Deliver guarantee rests on TEE integrity; a TEE compromise or attestation failure undermines the atomicity claim.","Correctness of the adaptor-signature construction is load-bearing for the atomic exchange.","As with any channel protocol, force-close and dispute paths must be sound to prevent fund lock-up or theft."],"interopsWith":["x402"],"sources":[{"title":"A402: Binding Cryptocurrency Payments to Service Execution for Agentic Commerce","url":"https://arxiv.org/abs/2603.01179","publisher":"arXiv (Li et al.)","date":"2026-03"},{"title":"A402 (DOI)","url":"https://doi.org/10.48550/arXiv.2603.01179","publisher":"arXiv","date":"2026-03"}],"lastVerified":"2026-09-02"},{"slug":"ant-amp","name":"AMP","fullName":"Agentic Mobile Protocol (AMP)","layer":"payment-execution","category":"hybrid","status":"live","createdBy":["Ant International"],"launched":"2026-04","rails":["mobile wallets","QR networks"],"settlement":"Settles through participating digital wallet and acquirer infrastructure in the Alipay+ ecosystem; includes a nano-grade agent-to-agent settlement mechanism for sub-cent transactions.","reversible":true,"humanInLoop":"optional","d2cFit":"strong","b2bFit":"moderate","summary":"An open-source payment protocol from Ant International for mobile interfaces — digital wallets, super apps, smart devices, and wearables — enabling AI agents to execute payments through existing mobile payment rails. Launched April 2026; global rollout across the Alipay+ ecosystem (10 wallets, 7 acquirers) announced September 2026. Ant International, Mastercard, and Visa are collaborating on a Know-Your-Agent (KYA) interoperability framework through BuildFin.ai (MAS).","howItWorks":"AMP is an **open payment protocol** designed for **mobile interfaces** — digital wallets, super apps, smart devices, and wearables — so AI agents can execute payments through the channels consumers already use, with no need to switch apps or change payment habits.\n\n- **Task authorization.** Consumers authorize a specific task and budget, not hand over their account. Real-time visibility and control let users see what agents are doing and revoke access at any time.\n- **Know-Your-Agent (KYA) Framework.** Establishes each agent's digital identity and certifies its authorized capabilities. The **Agent Trust Rating** is a dynamic risk-management mechanism that determines whether an agent is trustworthy and controls the level of autonomy it receives.\n- **AgentSafePay.** Provides a money-back guarantee for merchants against agentic-specific risks, giving merchant-side trust alongside consumer-side controls.\n- **Agent-to-agent (A2A) settlement.** A high-frequency nano-grade settlement mechanism enables automated transactions as small as $0.000001 between AI agents, with real-time accounting and clearing — addressing sub-cent machine-speed transactions that traditional payment rails cannot support.\n- **Open-source and multi-rail.** AMP is open-sourced on GitHub and designed to work across digital wallets, QR networks, and acquirer infrastructure. Phase I integration covers 10 Alipay+ wallets serving 1.5 billion user accounts and 7 global acquirers (Adyen, Allinpay, Checkout.com, Fiserv, Global Payments, Nuvei, Worldline).\n\nAnt International, Mastercard, and Visa are collaborating on a **KYA interoperability framework** through BuildFin.ai (convened by the Monetary Authority of Singapore) to standardize agent onboarding and identification across payment networks, building on the Safeguards for Agentic Finance at Runtime (SAFR) framework.","tradeoffs":["Primarily deployed within the Alipay+ ecosystem, which limits initial reach outside markets where Alipay+ wallets are prevalent (APAC-centric in Phase I).","Agent Trust Rating and KYA are Ant International constructs; cross-network interoperability depends on the Mastercard/Visa KYA collaboration delivering common standards.","AgentSafePay's money-back guarantee shifts risk from merchants to the protocol operator; the economics at scale (for nano-transactions) are unproven.","The claimed GitHub open-sourcing could not be independently verified via a specific repository URL at time of writing; the press release states it is available."],"securityNotes":["Agent Trust Rating is the gating mechanism for autonomy; manipulation of the rating or its inputs could elevate an untrusted agent's spending authority.","The nano-grade A2A settlement mechanism handles sub-cent transactions at machine speed, so rate-limiting and per-agent spending controls are load-bearing safety features.","KYA identity is established per agent; identity spoofing or credential sharing across agents could bypass per-agent controls."],"interopsWith":[],"sources":[{"title":"Ant International's Agentic Mobile Protocol Rolls Out Globally with Wallets and Acquirers","url":"https://www.ant-intl.com/en/news/detail/?hideNext=1&id=ant-internationals-agentic-mobile-protocol-rolls-out-globally-with-wallets-acquirers-initiating-collaboration-on-kya-interoperability-framework-with-mastercard-and-visa&tag=AMP","publisher":"Ant International","date":"2026-09"},{"title":"Ant International's Agentic Mobile protocol rolls out globally","url":"https://thepaypers.com/payments/news/ant-internationals-agentic-mobile-protocol-rolls-out-globally","publisher":"The Paypers","date":"2026-09-11"}],"lastVerified":"2026-09-14"},{"slug":"acp","name":"ACP","fullName":"Agentic Commerce Protocol (ACP)","layer":"payment-execution","category":"framework","status":"draft","createdBy":["OpenAI","Stripe"],"launched":"2025-09","rails":["cards","stablecoins"],"settlement":"Delegates settlement to existing payment providers (Stripe PaymentIntents, Shared Payment Tokens, or merchant-side processors); ACP governs the checkout session lifecycle.","reversible":null,"humanInLoop":"required","d2cFit":"strong","b2bFit":"moderate","specUrl":"https://github.com/agentic-commerce-protocol/agentic-commerce-protocol","summary":"An open interaction model and standard for AI agent–driven consumer purchases, co-developed by OpenAI and Stripe. Defines a checkout session lifecycle (create, update, complete, cancel) so agents can discover products, manage carts, and complete purchases on behalf of consumers with human approval at payment. Powers ChatGPT's Instant Checkout and is adopted by merchants including Etsy, Target, and Sephora. Still in beta as of September 2026.","howItWorks":"","tradeoffs":[],"securityNotes":[],"interopsWith":[],"sources":[],"lastVerified":"2026-09-23"},{"slug":"ucp","name":"UCP","fullName":"Universal Commerce Protocol (UCP)","layer":"agent-communication","category":"framework","status":"draft","createdBy":["Google"],"launched":"2026-01","rails":[],"settlement":"Delegates payment to pluggable payment handlers (Google Pay, Shop Pay, card processors); UCP standardizes the commerce session, not settlement.","reversible":null,"humanInLoop":"optional","d2cFit":"strong","b2bFit":"moderate","specUrl":"https://github.com/Universal-Commerce-Protocol","summary":"An open-source standard from Google for agentic commerce across the full shopping journey — discovery, cart, checkout, and post-purchase support. Co-developed with Shopify, Etsy, Wayfair, Target, and Walmart, and endorsed by 20+ ecosystem partners including Adyen, Mastercard, Stripe, and Visa. Compatible with A2A, AP2, and MCP. Powers checkout on Google AI Mode in Search and Gemini. Live since January 2026; expanded globally with cart, catalog, and identity-linking capabilities.","howItWorks":"","tradeoffs":[],"securityNotes":[],"interopsWith":[],"sources":[],"lastVerified":"2026-09-23"},{"slug":"npci-uap","name":"UAP","fullName":"NPCI Unified Agent Protocol (UAP)","layer":"payment-authorization","category":"framework","status":"draft","createdBy":["NPCI"],"rails":["UPI"],"settlement":"Delegates settlement to UPI's existing infrastructure (UPI Circle delegation and Reserve Pay fund blocks).","reversible":null,"humanInLoop":"optional","d2cFit":"strong","b2bFit":"weak","summary":"A reported national framework from India's NPCI to let AI agents execute small-ticket UPI payments using UPI Circle (delegated authority) and Reserve Pay (pre-blocked funds), with spending limits, identity checks, and audit trails. NPCI deferred the expected launch at Global Fintech Fest (September 8–11, 2026) pending regulatory review. At GFF on September 10, NPCI's chairman publicly described the protocol work for the first time, stating that AI agents may read intent but authentication and settlement must remain deterministic and auditable. No public specification has been released.","howItWorks":"","tradeoffs":[],"securityNotes":[],"interopsWith":[],"sources":[],"lastVerified":"2026-09-14"}],"deployments":[{"slug":"coingecko-x402","name":"CoinGecko x402 Endpoints","operator":"CoinGecko","protocolSlug":"x402","status":"live","useCase":"Market-data endpoints (token prices, on-chain data) exposed as pay-per-request: a flat $0.01 USDC per call, no account or API key required.","chains":["Base","Solana"],"target":"both","launched":"2026-03","url":"https://www.coingecko.com/","sources":[{"title":"Stripe adds x402 integration for USDC agent payments on Base (CoinGecko launch)","url":"https://www.theblock.co/post/389352/stripe-adds-x402-integration-usdc-agent-payments","publisher":"The Block","date":"2026-03"},{"title":"Pay-per-Call APIs for AI Agents (CoinGecko as canonical example)","url":"https://eco.com/support/en/articles/14846274-pay-per-call-apis-for-ai-agents","publisher":"eco.com (explainer)"}],"lastVerified":"2026-09-02"},{"slug":"coinbase-agent-market","name":"Coinbase Agent.market","operator":"Coinbase","protocolSlug":"x402","status":"live","useCase":"An x402-native marketplace / app-store for agent services: an operator publishes an endpoint and sets a price, and any x402-aware agent can discover and pay for it with no contract or onboarding.","chains":["Base"],"target":"both","url":"https://docs.cdp.coinbase.com/x402","sources":[{"title":"Pay-per-Call APIs for AI Agents (Agent.market as an x402 app store)","url":"https://eco.com/support/en/articles/14846274-pay-per-call-apis-for-ai-agents","publisher":"eco.com (explainer)"}],"lastVerified":"2026-09-02"},{"slug":"cloudflare-agents-x402","name":"Cloudflare Agents SDK + Monetization Gateway","operator":"Cloudflare","protocolSlug":"x402","status":"live","useCase":"x402 integrated into Cloudflare Workers: an Agents SDK example gates routes behind a price, and an x402-proxy Worker template sits in front of any origin to charge agents (and crawlers) per request.","chains":["Base","Base Sepolia"],"target":"both","url":"https://developers.cloudflare.com/agents/tools/payments/x402/charge-for-http-content/","sources":[{"title":"x402 HTTP Payments example (Cloudflare Agents SDK)","url":"https://github.com/cloudflare/agents/blob/main/examples/x402/README.md","publisher":"Cloudflare"},{"title":"Charge for HTTP content (x402-proxy Worker template)","url":"https://developers.cloudflare.com/agents/tools/payments/x402/charge-for-http-content/","publisher":"Cloudflare"}],"lastVerified":"2026-09-02"},{"slug":"stripe-machine-payments","name":"Stripe Machine Payments","operator":"Stripe","protocolSlug":"stripe-mpp","status":"live","useCase":"Stripe's production machine-payments surface: accepts agent payments via MPP (card + stablecoin, one-shot through recurring/streaming) and also supports x402 for stablecoin-only flows, settling through Stripe PaymentIntents.","chains":["Tempo","Base"],"target":"B2B","launched":"2026-03","url":"https://docs.stripe.com/payments/machine","sources":[{"title":"Machine payments — Overview","url":"https://docs.stripe.com/payments/machine","publisher":"Stripe"},{"title":"MPP payments — Machine Payments Protocol","url":"https://docs.stripe.com/payments/machine/mpp","publisher":"Stripe"}],"lastVerified":"2026-09-02"},{"slug":"circle-wallets-x402","name":"Circle Wallets + x402 Reference Workflow","operator":"Circle","protocolSlug":"x402","status":"live","useCase":"A reference workflow for autonomous agents: provision a Circle MPC developer wallet, fund it with USDC, and clear x402 paywalls via the Circle Signing API (EIP-3009 transferWithAuthorization).","chains":["Base"],"target":"both","url":"https://www.circle.com/","sources":[{"title":"x402 Protocol Explained (Circle Wallets + USDC reference workflow)","url":"https://eco.com/support/en/articles/14839402-x402-protocol-explained","publisher":"eco.com (explainer)"}],"lastVerified":"2026-09-02"},{"slug":"ap2-paypal-pilot","name":"AP2 via PayPal","operator":"PayPal (with Google)","protocolSlug":"ap2","status":"pilot","useCase":"An early production pilot of AP2's mandate flow: PayPal acts as the credential provider while a merchant runs a Google Cloud shopping agent, exercising Intent/Cart/Payment mandates end-to-end.","chains":[],"target":"D2C","launched":"2025-09","url":"https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol","sources":[{"title":"Powering AI commerce with the new Agent Payments Protocol (AP2)","url":"https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol","publisher":"Google Cloud","date":"2025-09-16"},{"title":"AP2 (Agent Payments Protocol) Explained (PayPal pilot, v0.x status)","url":"https://eco.com/support/en/articles/14845479-ap2-agent-payments-protocol-explained","publisher":"eco.com (explainer)"}],"lastVerified":"2026-09-02"},{"slug":"zeroclick","name":"ZeroClick","operator":"ZeroClick","protocolSlug":"x402","status":"live","useCase":"A storefront and paid-proxy layer that turns any API into an agent-purchasable service: agents discover a seller's machine-readable pay URL, pay per request or by plan over x402 (Stripe's MPP is also supported), and ZeroClick verifies payment, signs the call, and forwards it to the origin — settling revenue to the seller's Stripe account in USDC or fiat.","chains":["Base","Tempo"],"target":"both","url":"https://zeroclick.ai/","sources":[{"title":"What is ZeroClick? — documentation","url":"https://docs.zeroclick.ai/","publisher":"ZeroClick"},{"title":"ZeroClick — Sell Your Product to AI Agents","url":"https://zeroclick.ai/","publisher":"ZeroClick"}],"lastVerified":"2026-09-02"},{"slug":"polygon-x402","name":"Polygon x402 Facilitators","operator":"Polygon","protocolSlug":"x402","status":"live","useCase":"x402 v2 facilitators on Polygon mainnet and Amoy testnet: sellers accept USDC micropayments for APIs and agent services with sub-2-second settlement, low fees, and gas sponsorship via the Coinbase CDP facilitator.","chains":["Polygon"],"target":"both","launched":"2026-03","url":"https://docs.polygon.technology/payment-services/agentic-payments/x402/intro","sources":[{"title":"Coinbase's x402 Facilitator Launches on Polygon","url":"https://www.coinbase.com/developer-platform/discover/launches/x402facilitator-polygon","publisher":"Coinbase","date":"2026-03-11"},{"title":"x402 protocol: agentic payments over HTTP — Polygon documentation","url":"https://docs.polygon.technology/payment-services/agentic-payments/x402/intro","publisher":"Polygon"}],"lastVerified":"2026-09-07"},{"slug":"xpay-x402","name":"X Pay x402 Gateway","operator":"X-Pay Technologies","protocolSlug":"x402","status":"live","useCase":"An x402 payment gateway on Base mainnet: any HTTP endpoint can name a price, take payment in USDC, and serve its response in a single request — with no account, API key, or subscription. Includes session keys with spending limits, merchant dashboards, and 1% of settled volume pricing.","chains":["Base"],"target":"both","launched":"2026-09","sources":[{"title":"X Pay is live on mainnet (GlobeNewsWire press release)","url":"https://columbus.newsnetmedia.com/story/438585/x-pay-is-live-on-mainnet/","publisher":"X-Pay Technologies (via GlobeNewsWire)","date":"2026-09-11"}],"lastVerified":"2026-09-14"},{"slug":"mc-agent-connect","name":"Mastercard Agent Connect","operator":"Mastercard","protocolSlug":"mc-ap4m","status":"live","useCase":"A single-integration merchant solution that links AI agents, commerce services, and payment providers: agents discover product catalogues, confirm pricing and fulfilment, and complete transactions using secure payment credentials (secured via Agent Pay and Verifiable Intent). Launching first in the US with Samsung, Trip.com, Global Payments, Nexi, Worldline, and others.","chains":[],"target":"both","launched":"2026-09","url":"https://thepaypers.com/payments/news/mastercard-launches-agent-connect-for-agentic-commerce","sources":[{"title":"Mastercard launches Agent Connect for agentic commerce","url":"https://thepaypers.com/payments/news/mastercard-launches-agent-connect-for-agentic-commerce","publisher":"The Paypers","date":"2026-09-10"}],"lastVerified":"2026-09-14"},{"slug":"circle-arc-x402","name":"Circle x402 Facilitator Service on Arc","operator":"Circle","protocolSlug":"x402","status":"live","useCase":"A hosted x402 facilitator that lets sellers accept USDC payments from AI agents across Arc, Base, and Polygon through a single integration — no relayer keys, gas wallets, or per-chain settlement infrastructure required. Circle verifies buyer-signed EIP-3009 authorizations, screens both parties, and settles on-chain. Launched with Arc mainnet (September 16, 2026); agentic payments announced live September 19.","chains":["Arc","Base","Polygon"],"target":"both","launched":"2026-09","url":"https://www.circle.com/pressroom/circle-launches-arc-mainnet-an-economic-operating-system-for-the-internet","sources":[{"title":"Circle Launches Arc Mainnet, an Economic Operating System for the Internet","url":"https://www.circle.com/pressroom/circle-launches-arc-mainnet-an-economic-operating-system-for-the-internet","publisher":"Circle","date":"2026-09-16"},{"title":"Arc Launches Agentic Payments with USDC Across 3 Chains, Removing Gas Wallet Hassles","url":"https://www.cryptoninjas.net/news/arc-launches-agentic-payments-with-usdc-across-3-chains-removing-gas-wallet-hassles/","publisher":"CryptoNinjas","date":"2026-09-20"}],"lastVerified":"2026-09-23"},{"slug":"alchemy-agentcard-mc","name":"Alchemy AgentCard + Mastercard Agent Pay","operator":"Alchemy","protocolSlug":"mc-ap4m","status":"live","useCase":"A unified agent identity and payment product: developers provision an agent in under a minute via CLI with a dedicated email, phone number, stablecoin wallet, and one-time-use tokenized Mastercard credentials linked to a user's existing card. Supports Mastercard Agent Pay and Verifiable Intent, with issuer-enforced spending limits, merchant-category restrictions, and geographic controls. Agents can transact anywhere Mastercard is accepted online.","chains":[],"target":"D2C","launched":"2026-09","url":"https://agentcard.ai/","sources":[{"title":"Alchemy Unlocks AI Agent Purchases Anywhere Mastercard is Accepted Online via AgentCard","url":"https://www.prnewswire.com/news-releases/alchemy-unlocks-ai-agent-purchases-anywhere-mastercard-is-accepted-online-via-agentcard-302882149.html","publisher":"Alchemy (via PR Newswire)","date":"2026-09-17"},{"title":"Alchemy adds Mastercard Agent Pay to AgentCard","url":"https://thepaypers.com/payments/news/alchemy-adds-mastercard-agent-pay-to-agentcard","publisher":"The Paypers","date":"2026-09-21"}],"lastVerified":"2026-09-23"}],"changelog":[{"date":"2026-09-23","kind":"note","title":"2026-W39 market review — 2 new draft protocols, 2 new deployments","body":"Weekly automated review. Changes this run:\n\n- **ACP** (new, draft): OpenAI & Stripe's Agentic Commerce Protocol — an open checkout-session standard for AI agent–driven consumer purchases. Powers ChatGPT Instant Checkout; adopted by Etsy, Target, Sephora, and others. Beta since September 2025. Added as draft pending full human review of protocol details.\n- **UCP** (new, draft): Google's Universal Commerce Protocol — an open standard for agentic commerce across the full shopping journey (discovery, cart, checkout, post-purchase). Co-developed with Shopify, Target, Walmart, and endorsed by 20+ partners. Live since January 2026. Added as draft pending full human review.\n- **Circle x402 Facilitator on Arc** (new deployment, live): Circle's hosted x402 Facilitator Service launched with Arc mainnet on September 16, enabling USDC agent payments across Arc, Base, and Polygon through a single integration with no relayer keys or gas wallets.\n- **Alchemy AgentCard + Mastercard** (new deployment, live): Alchemy integrated Mastercard Agent Pay into AgentCard on September 17, letting AI agents make purchases anywhere Mastercard is accepted using one-time-use tokenized credentials with Verifiable Intent support.\n\nAlso noted: Coinbase x402 facilitator on Solana shipped three improvements on Sep 17 — upto payment scheme now live, verify latency cut 66% to 75 ms, settle latency down 20% to 900 ms, and automatic SDK retry for pending settlements.","refs":["acp","ucp","circle-arc-x402","alchemy-agentcard-mc"],"sources":[{"title":"Agentic Commerce Protocol — GitHub repository","url":"https://github.com/agentic-commerce-protocol/agentic-commerce-protocol","publisher":"OpenAI & Stripe (GitHub)"},{"title":"New tech and tools for retailers to succeed in an agentic shopping era (UCP launch)","url":"https://blog.google/products/ads-commerce/agentic-commerce-ai-tools-protocol-retailers-platforms/","publisher":"Google","date":"2026-01-11"},{"title":"Circle Launches Arc Mainnet, an Economic Operating System for the Internet","url":"https://www.circle.com/pressroom/circle-launches-arc-mainnet-an-economic-operating-system-for-the-internet","publisher":"Circle","date":"2026-09-16"},{"title":"Alchemy Unlocks AI Agent Purchases Anywhere Mastercard is Accepted Online via AgentCard","url":"https://www.prnewswire.com/news-releases/alchemy-unlocks-ai-agent-purchases-anywhere-mastercard-is-accepted-online-via-agentcard-302882149.html","publisher":"Alchemy (via PR Newswire)","date":"2026-09-17"},{"title":"Coinbase Upgrades x402 Facilitator on Solana: Upto Scheme Live, Verify Latency Cut 66%","url":"https://solanacompass.com/news/coinbase-upgrades-x402-facilitator-on-solana-upto-scheme-live-verify-latency-cut-66","publisher":"Solana Compass","date":"2026-09-18"}]},{"date":"2026-09-14","kind":"note","title":"2026-W38 market review — 1 new protocol, 2 new deployments, 1 draft update","body":"Weekly automated review. Changes this run:\n\n- **AMP** (new, live): Ant International's Agentic Mobile Protocol — an open-source payment protocol for mobile interfaces (wallets, super apps, wearables). Launched April 2026; global rollout across 10 Alipay+ wallets (1.5B user accounts) and 7 acquirers (Adyen, Checkout.com, Fiserv, Global Payments, Nuvei, Worldline) announced September 11. Features KYA agent identity, Agent Trust Rating, AgentSafePay merchant guarantee, and nano-grade A2A settlement. Ant International, Mastercard, and Visa began KYA interoperability collaboration through BuildFin.ai (MAS).\n- **X Pay** (new deployment, live): X-Pay Technologies' x402 gateway went live on Base mainnet September 11, settling real USDC per-request with no account or API key required.\n- **Mastercard Agent Connect** (new deployment, live): A single-integration merchant solution launched September 9, linking AI agents to product catalogues and secure checkout via Agent Pay / Verifiable Intent. Launching first in the US with Samsung, Trip.com, Global Payments, Nexi, Worldline, and others.\n- **NPCI UAP** (draft updated): NPCI deferred the expected UAP launch at Global Fintech Fest (Sep 8–11) pending regulatory review. NPCI's chairman publicly described the protocol work for the first time at GFF on Sep 10, stating agents may read intent but authentication and settlement must remain deterministic.\n- **Visa TAP** re-verified: added Visa EU July 2 press release confirming live agent-executed transactions with 31 named European issuers and 4 merchants.\n- **Mastercard AP4M** re-verified: Agent Connect confirms AP4M expansion; added The Paypers source.","refs":["ant-amp","xpay-x402","mc-agent-connect","npci-uap","visa-tap","mc-ap4m"],"sources":[{"title":"Ant International's Agentic Mobile Protocol Rolls Out Globally with Wallets and Acquirers","url":"https://www.ant-intl.com/en/news/detail/?hideNext=1&id=ant-internationals-agentic-mobile-protocol-rolls-out-globally-with-wallets-acquirers-initiating-collaboration-on-kya-interoperability-framework-with-mastercard-and-visa&tag=AMP","publisher":"Ant International","date":"2026-09"},{"title":"X Pay is live on mainnet","url":"https://columbus.newsnetmedia.com/story/438585/x-pay-is-live-on-mainnet/","publisher":"X-Pay Technologies (via GlobeNewsWire)","date":"2026-09-11"},{"title":"Mastercard launches Agent Connect for agentic commerce","url":"https://thepaypers.com/payments/news/mastercard-launches-agent-connect-for-agentic-commerce","publisher":"The Paypers","date":"2026-09-10"},{"title":"NPCI Says AI Shouldn't Approve UPI Payments at GFF 2026","url":"https://www.medianama.com/2026/09/223-npci-ai-agents-upi-payments/","publisher":"MediaNama","date":"2026-09-10"}]},{"date":"2026-09-07","kind":"note","title":"2026-W37 market review — 1 new protocol, 1 upgrade, 1 new deployment, 1 draft","body":"Weekly automated review. Changes this run:\n\n- **Visa TAP** (new, live): Visa's Trusted Agent Protocol — a cryptographic trust framework (RFC 9421 HTTP Message Signatures) for agentic commerce on the Visa network. Announced October 2025 with Cloudflare; live in Europe with 30+ issuers since July 2026. Developer docs and GitHub samples verified.\n- **AP4M** (upgraded, draft → live): Mastercard Agent Pay for Machines — fleshed out from draft with howItWorks, tradeoffs, security notes, and a verified third-party source. Primary Mastercard URLs still block automated fetchers; verified via Electronic Payments International.\n- **Polygon x402** (new deployment, live): Polygon x402 v2 facilitators on mainnet and Amoy testnet, with Coinbase CDP gas sponsorship. Live since March 2026.\n- **NPCI UAP** (new, draft): NPCI's Unified Agent Protocol — a reported national framework for agentic UPI payments, expected at Global Fintech Fest (Sep 8–11, 2026). Added as draft pending official confirmation.","refs":["visa-tap","mc-ap4m","polygon-x402","npci-uap"],"sources":[{"title":"Visa Introduces Trusted Agent Protocol: An Ecosystem-Led Framework for AI Commerce","url":"https://usa.visa.com/about-visa/newsroom/press-releases.releaseId.21716.html","publisher":"Visa","date":"2025-10-14"},{"title":"Mastercard launches AP4M for AI-led transactions","url":"https://www.electronicpaymentsinternational.com/news/mastercard-launches-ap4m-for-ai-led-transactions/","publisher":"Electronic Payments International","date":"2026-06-11"},{"title":"Coinbase's x402 Facilitator Launches on Polygon","url":"https://www.coinbase.com/developer-platform/discover/launches/x402facilitator-polygon","publisher":"Coinbase","date":"2026-03-11"}]},{"date":"2026-09-03","kind":"note","title":"2026-W36 market review — 1 new protocol, 1 draft, 3 status updates","body":"Weekly automated review. Changes this run:\n\n- **x402**: governance transferred to the vendor-neutral **x402 Foundation** under the Linux Foundation (announced April 2026, operationally active July 2026 with 40 members). Protocol V2 introduced CAIP-2 network identifiers, scoped packages, and new header names. Sources and summary updated.\n- **AP2**: v0.2 released April 2026 with Human-Not-Present autonomous payment flows. Google donated AP2 and the Verifiable Intent framework (co-developed with Mastercard) to the **FIDO Alliance**. Mandate model reorganized from three types to two (Checkout + Payment, each Open or Closed). Sources updated.\n- **MPP**: corrected co-authorship to Stripe **and Tempo**; added open spec at mpp.dev and Stripe blog announcement. Still early access/beta.\n- **P3P** (new, live): Pine Labs Payment Protocol — India's first agentic payment protocol on UPI. Uses HTTP 402, UPI mandate infrastructure, and a Grantex identity layer. Live with Gullak since June 2026.\n- **AP4M** (new, draft): Mastercard Agent Pay for Machines — machine-to-machine payment service launched June 2026 with 30+ partners. Added as draft because the primary Mastercard source URLs could not be confirmed to return HTTP 200 from automated fetchers.","refs":["x402","ap2","stripe-mpp","p3p","mc-ap4m"],"sources":[{"title":"Linux Foundation Announces Operational Launch of x402 Foundation","url":"https://www.linuxfoundation.org/press/linux-foundation-announces-operational-launch-of-x402-foundation-to-standardize-internet-native-payments-for-ai-agents-and-applications","publisher":"Linux Foundation","date":"2026-07-14"},{"title":"Google donates Agent Payments Protocol to FIDO Alliance","url":"https://blog.google/products-and-platforms/platforms/google-pay/agent-payments-protocol-fido-alliance/","publisher":"Google","date":"2026-04-28"},{"title":"Pine Labs Launches P3P — India's First Agentic Payment Protocol Built on UPI","url":"https://www.pinelabs.com/media-analyst/the-ai-agent-can-now-pay-pine-labs-launches-p3p-indias-first-agentic-payment-protocol-built-on-upi","publisher":"Pine Labs","date":"2026-06-11"}]},{"date":"2026-09-02","kind":"note","title":"Registry seeded and verified","body":"Initial registry published with **x402**, **A2A**, **AP2**, and **Stripe MPP** as verified entries, plus draft scaffolds pending verification. All non-draft claims carry sources and a verification date.","refs":["x402","a2a","ap2","stripe-mpp"]},{"date":"2026-09-02","kind":"status-change","title":"Verified ERC-4337 and A402; added ZeroClick deployment","body":"Verified two former drafts against primary sources: **ERC-4337** (account-abstraction custody primitive, now live) and **A402** (a research-stage architecture, now proposed). **ZeroClick** was reclassified from a draft protocol to a real deployment, since it is a storefront/proxy built on x402 and MPP rather than a new rail.","refs":["erc-4337","a402","zeroclick"],"sources":[{"title":"ERC-4337: Account Abstraction Using Alt Mempool","url":"https://eips.ethereum.org/EIPS/eip-4337","publisher":"Ethereum Improvement Proposals"},{"title":"A402: Binding Cryptocurrency Payments to Service Execution for Agentic Commerce","url":"https://arxiv.org/abs/2603.01179","publisher":"arXiv (Li et al.)","date":"2026-03"}]},{"date":"2026-03-01","kind":"new-deployment","title":"Stripe Machine Payments and CoinGecko x402 endpoints added","body":"Recorded Stripe's machine-payments surface (MPP, with x402 support) and CoinGecko's pay-per-call market-data endpoints priced in USDC.","refs":["stripe-mpp","stripe-machine-payments","coingecko-x402"],"sources":[{"title":"Machine payments — Overview","url":"https://docs.stripe.com/payments/machine","publisher":"Stripe"}]},{"date":"2025-09-16","kind":"new-protocol","title":"Added AP2 with the A2A layer distinction","body":"Added the **Agent Payments Protocol (AP2)** as a payment-*authorization* layer and clarified that **A2A** is agent-*communication* only — payments ride on top via other protocols. Logged the PayPal-with-Google AP2 pilot.","refs":["ap2","a2a","ap2-paypal-pilot"],"sources":[{"title":"Powering AI commerce with the new Agent Payments Protocol (AP2)","url":"https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol","publisher":"Google Cloud","date":"2025-09-16"}]},{"date":"2025-05-01","kind":"new-protocol","title":"Added x402 with its first deployments","body":"Seeded **x402** (HTTP-402 stablecoin payments) as a live payment-execution protocol, along with Coinbase Agent.market, Cloudflare's Agents SDK gateway, and the Circle Wallets reference workflow.","refs":["x402","coinbase-agent-market","cloudflare-agents-x402","circle-wallets-x402"],"sources":[{"title":"x402 — official protocol site","url":"https://www.x402.org/","publisher":"x402 Foundation"}]}]}