What’s new (and why it matters)

• Apps in ChatGPT + Apps SDK (preview). You can design UI that lives in ChatGPT (cards, carousels, fullscreen) and connect it to your systems via MCP. OpenAI plans to open submissions later this year.
• Agentic Commerce Protocol (ACP). An open, Apache-licensed spec—co-developed by OpenAI and Stripe—that standardizes how agents and merchants transact. The first product on ACP is Instant Checkout in ChatGPT.
• Merchants keep their stack. With ACP, you remain merchant of record; payments flow through your existing PSP (e.g., via Stripe’s Shared Payment Token), and you own fulfillment, taxes, refunds, and chargebacks.

How the pieces fit (architecture at a glance)

1. ChatGPT UI (Apps SDK)
   • Your app renders native components (lists, product tiles, checkout review) in an iframe and communicates with ChatGPT via window.openai.
2. Your MCP server
   • Exposes tool contracts for catalog search, inventory, pricing, shipping estimates, and order creation; returns structured results that hydrate the UI.
3. ACP checkout
   • When the user buys, ChatGPT drives Instant Checkout using ACP. OpenAI is not the merchant of record; your PSP processes the payment (e.g., via a Shared Payment Token issued by Stripe).

Guided shopping patterns that work in ChatGPT

1) Search → Compare → Configure
Return a ranked list (price, availability, delivery ETA) with a single primary action (“Review & Checkout”). Keep the composer visible so users can refine naturally. (Design guidelines favor compact, task-focused components; use fullscreen sparingly.)

2) Bundles & assistants
Expose tools like suggest_bundle(sku, budget) and render a compact configurator. Your UI should mirror your tool schemas—no extra fields beyond what the tool needs.

3) Checkout review → Instant Checkout
Show line items, shipping, taxes, and policies; on confirm, hand off to ACP. Instant Checkout runs in OpenAI’s UI, but payment, risk, tax, and acceptance remain on your systems/PSP.

Implementing ACP (practical guide for merchants)

• Start with concepts & specs. Read ACP Get started, Key concepts, and Production readiness; review Agentic Checkout, Delegated Payment, and Product Feed specs.
• Payments model. ACP’s Delegated Payment lets OpenAI request a constrained, single-use payment; your PSP returns a token that you charge. Stripe’s Shared Payment Token is the first implementation; more PSPs are coming.
• Availability. Instant Checkout in ChatGPT is currently restricted to approved partners. You can apply while building ACP support.

Security, privacy, and compliance (what your reviewers need)

• Write-action confirmations & least privilege. In Apps SDK, label any tool that changes state (e.g., create_order) as a write action so ChatGPT can insert human confirmation prompts. Keep scopes minimal; assume injection attempts; validate all inputs server-side.
• Data minimization & retention. Send only what the current prompt requires; redact PII in logs; publish retention policy prior to submission.
• Payments & PCI. ACP keeps merchants on their existing PSP. For PSPs/Level-1 merchants integrating Delegated Payment directly, understand PCI scope; otherwise, use a PSP implementation (e.g., Stripe’s Shared Payment Token).

Build plan (source-aligned)

Phase 1 — POC in Developer Mode (2–3 weeks)

• Stand up an MCP server with tools: search_products, get_price, estimate_shipping, create_order.
• Ship minimal Apps SDK components (list + detail + review). Test end-to-end in Developer Mode.

Phase 2 — ACP integration (2–4 weeks)

• Implement Agentic Checkout flows and wire Delegated Payment to your PSP (or Stripe’s Shared Payment Token). Prepare a Product Feed for discovery.

Phase 3 — Hardening & submission prep

• Apply Security & Privacy guidance; verify write-action confirmations; finalize privacy policy. Apps SDK is in preview; submissions open later this year.

KPIs you can instrument on day one

• Discovery precision/recall for shopping prompts (driven by your app metadata).
• Add-to-review rate from product lists; confirmation rate on write actions.
• Checkout completion time and decline reasons (from your PSP).

Common pitfalls (and how to avoid them)

• Rebuilding your entire storefront in fullscreen. OpenAI’s design guidance favors lightweight, conversational components; reserve fullscreen for focused steps (review, policies).
• Skipping write-action labeling. Without it, ChatGPT can’t gate risky operations with confirmations—a policy and UX miss.
• Misunderstanding Instant Checkout availability. It exists, but only for approved partners right now; build ACP support while you apply.

Why this channel is strategic now

OpenAI is explicitly positioning apps in ChatGPT and ACP to enable shopping where discovery happens—inside conversations. You get distribution (app suggestions + upcoming directory) and conversion (Instant Checkout) without abandoning your existing payments stack or merchant-of-record status.

How we can help

We design contract-first MCP tools, Apps SDK UI that converts, and ACP integrations (including Stripe Shared Payment Token). Our build plan and controls map 1-to-1 to OpenAI’s Apps SDK, Security & Privacy, and Agentic Commerce docs—so your app is both delightful and review-ready.