Changelog

Weekly automated review. Changes this run:

• 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.
• 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.
• 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.
• 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.

Also 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.

Weekly automated review. Changes this run:

• 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).
• 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.
• 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.
• 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.
• Visa TAP re-verified: added Visa EU July 2 press release confirming live agent-executed transactions with 31 named European issuers and 4 merchants.
• Mastercard AP4M re-verified: Agent Connect confirms AP4M expansion; added The Paypers source.

Weekly automated review. Changes this run:

• 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.
• 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.
• Polygon x402 (new deployment, live): Polygon x402 v2 facilitators on mainnet and Amoy testnet, with Coinbase CDP gas sponsorship. Live since March 2026.
• 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.

Weekly automated review. Changes this run:

• 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.
• 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.
• MPP: corrected co-authorship to Stripe and Tempo; added open spec at mpp.dev and Stripe blog announcement. Still early access/beta.
• 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.
• 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.

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.

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.

Recorded Stripe's machine-payments surface (MPP, with x402 support) and CoinGecko's pay-per-call market-data endpoints priced in USDC.

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.

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.