2026-W39 market review — 2 new draft protocols, 2 new deployments

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.