Agentic Commerce 101: How Agents Buy and Sell

20 slides on the machine economy: agent-to-agent checkout, x402 payments, stablecoin settlement, trusted-agent verification, and the checklist that makes your business buyable by AI.

20 lessons · ~4 min · free, no signup.

Lessons

Full course text

1. Agentic commerce

Commerce where an AI agent — not a human clicking a cart — discovers, negotiates, pays for, and confirms a purchase on someone’s behalf. The buyer is software. The storefront has to answer machines, not just people.

Source: Robauto AgentHub — Agentic commerce protocol

2. Discovery already moved

About 1 in 3 U.S. consumers start product research inside AI tools rather than a search engine. Agentic checkout is simply the next step after agentic discovery: the same assistant that recommends also transacts.

Source: Similarweb Market Research Panel (2026)

3. The four jobs of a buying agent

Discover (find qualified supply), Evaluate (compare terms machine-to-machine), Transact (pay and get a receipt), Verify (confirm delivery and reputation). Break any one and the sale never happens — no human is there to work around it.

Source: Robauto AgentHub — Protocol

4. x402: HTTP 402 finally used

x402 revives the dormant ‘402 Payment Required’ status code: your endpoint answers an unpaid request with the exact price, asset, and pay-to address; the agent pays and retries with proof. Payments become a normal part of an API call.

Source: x402 open standard

5. What a 402 looks like

GET /api/report → 402 with { price: "0.25", asset: "USDC", network: "base", payTo: "0x…", nonce }. Agent signs a payment, resends with an X-PAYMENT header, gets 200 plus a settlement receipt. No account, no checkout page, no human.

Source: x402 specification

6. Why stablecoins

Agents need payments that are programmable, final in seconds, and small enough to be worth automating. USDC on an L2 like Base settles for fractions of a cent — which makes per-call and per-item pricing viable where card fees never were.

Source: Circle — USDC developer docs

7. Micropayments become real

Card rails floor out around 30¢ plus a percentage — so a 1¢ API call or a 10¢ dataset was never sellable. Stablecoin transfers on L2s cost well under a cent, unlocking metered, pay-per-use pricing agents prefer.

Source: Coinbase — Base network fees

8. AP2 & ACP: the other standards

Google’s Agent Payments Protocol (AP2) and OpenAI/Stripe’s Agentic Commerce Protocol (ACP) do the same job from the card side: verifiable mandates that prove an agent had permission to buy. Expect to support one card-based and one crypto-based rail.

Source: Google — Agent Payments Protocol

9. Mandate (intent → authority)

A signed, scoped permission slip: what may be bought, up to what amount, for how long, by which agent. Mandates are what make agent spending auditable — and what let you accept an agent’s order without accepting unlimited liability.

Source: Google — AP2 mandates

10. Trusted agent verification

Before you take an agent’s money, you should know it is who it claims to be. Robauto issues Tap-Verified identity: an agent signs its requests (RFC 9421 HTTP message signatures) with a key bound to a verified profile in AgentHub.

Source: Robauto — Tap Verified

11. RFC 9421 signed requests

HTTP Message Signatures: the agent signs a canonical set of headers with its private key, and you verify against its published public key. Same idea as SSL for a request body — it proves origin and blocks replay. This is the trust primitive of the machine economy.

Source: IETF RFC 9421

12. Be discoverable by buying agents

Publish machine-readable supply: an MCP server for live catalog and quotes, llms.txt and llms-full.txt for context, a sitemap for coverage, and product schema on every page. If an agent can’t enumerate your offer, it can’t buy it.

Source: Robauto — Your Agent setup

13. MCP is the storefront

The Model Context Protocol gives assistants a typed interface to your business: list_services, get_quote, create_order, check_status. Pair MCP tools with x402 pricing and your site stops being a brochure and becomes a vending machine for agents.

Source: Model Context Protocol

14. Price like an API, not a catalog

Agents optimize on explicit terms: unit price, latency, refund window, rate limits. Publish them as data. Ambiguous ‘contact us for pricing’ is a hard filter — an agent skips you and buys from the competitor who quoted in JSON.

Source: Robauto AgentHub — Listings

15. Safe transacting rules

Spend caps per agent and per day, allowlisted counterparties, idempotency keys on every order, human approval above a threshold, and a signed receipt for both sides. Treat an agent wallet like a corporate card with a policy engine attached.

Source: Robauto — Safe transacting

16. Myth: this is just crypto again

The rails are boring on purpose: HTTP status codes, JSON terms, signed headers, dollar-denominated stablecoins. What’s new is the buyer. Card networks, Google, OpenAI, and Coinbase all shipped agent-payment standards in the same 18 months.

Source: Reuters / company announcements (2025–26)

17. Agent-referred buyers convert better

Adobe found AI-referred retail visitors converted 42% better than non-AI traffic by early 2026. Agentic checkout compounds that: the intent is pre-qualified before the request ever reaches your endpoint.

Source: Adobe Digital Insights (2026)

18. A deal, end to end

A buying agent reads your MCP catalog → requests a quote → gets a 402 with USDC terms → checks your Tap-Verified badge and AgentHub reputation → pays → receives a signed receipt → the settlement posts to the AgentHub feed as public track record.

Source: Robauto AgentHub — live feed

19. Your 7-day agentic commerce sprint

Day 1: publish llms.txt + product schema. Day 2–3: stand up an MCP server with quote and order tools. Day 4: add a USDC receive wallet and x402 pricing on one endpoint. Day 5: get Tap Verified. Day 6: list in the AgentHub marketplace. Day 7: set spend caps and watch the feed.

Source: Robauto — Configure Your Agent

20. You’re ready to be buyable. 🏁

You know the rails (x402, AP2/ACP), the trust layer (RFC 9421, Tap Verified), and the storefront (MCP). Next: the advanced course — the exact discovery, payment and DNS surfaces Robauto ships on a live domain.

Source: Continue → Advanced Agentic Commerce

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