Any AI agent can buy a SimFuse eSIM

Plain HTTP, no SDK to install, no sandbox to apply for. Start with the discovery document and follow the links.

What answers today

Four ways in, one checkout engine behind all of them. There is no second catalog, no separate price list and no agent-only inventory: an agent buys the same plan at the same live price a traveller does.

• Agentic Commerce Protocol. The full seller API: create a checkout session, update it, complete it. We implement ACP directly rather than through a payment platform's suite, which is what lets us declare our own settlement handler. /.well-known/acp.json
• Universal Commerce Protocol. A shopping service at the same checkout engine, for clients that speak UCP instead. We declare only the checkout capability, because checkout is all we route. /.well-known/ucp
• Product feed. Every plan we sell, priced, with data allowance, validity and destination as structured attributes. Keyless on purpose: a catalog that needs a key to read is a catalog nobody crawls. /agentic/feeds/products
• OpenAPI and Machine Payment Protocol. The machine-readable description of the API, with pricing attached to the operations you can pay for. This is the document to hand a client that discovers services rather than being pointed at them. /openapi.json
• x402 on-chain purchase. One request buys one plan. Ask for a plan, get a 402 quoting the amount in USDC, sign the authorization, retry. Settlement is synchronous, so there is no pending window and nothing to poll. /agentic/x402/purchase/{id}
• Agent registration. How to get a credential, written for a reader that is not a person. Post your agent's name, receive a key, start buying. It is also reachable by following the WWW-Authenticate header on any 401 from us. /auth.md

Buying a plan, start to finish

Four requests. The first two need no credential at all, and the third is where you get one.

1. Discover. Read the discovery document at our primary domain. It names the API base, the protocol version, the payment handlers we accept and where to register.
2. Read the catalog. Page the product feed, or fetch a single plan's price. Ids in the feed are the ids checkout expects, so nothing has to be resolved in between.
3. Register yourself. Post a name and get a key back. No form, no review, no waiting. The key lasts a year and is shown exactly once, so store it before you close the response.
4. Buy. Create a session with the plans you want, complete it, and the eSIM is provisioned. Prices are frozen for the life of the session, so the total you were quoted is the total you settle.

# 1. Find us. Everything else is linked from here.
curl https://simfuse.app/.well-known/acp.json

# 2. Read the catalog. No credential needed.
curl "https://api.simfuse.app/agentic/feeds/products?per_page=5"

# 3. Register your agent. No human in the loop.
curl -X POST https://api.simfuse.app/agentic/keys \
  -H "Content-Type: application/json" \
  -d '{"agent_name":"my-assistant","contact_email":"you@example.com"}'

# 4. Buy a plan, using an id straight from the feed.
curl -X POST https://api.simfuse.app/agentic/checkout_sessions \
  -H "Authorization: Bearer $SIMFUSE_AGENT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"items":[{"id":"<package id from the feed>","quantity":1}],"currency":"EUR"}'

Completing the session returns payment instructions for the handler you chose. The full request and response shapes are in the OpenAPI description. https://simfuse.app/openapi.json

Why this works here and stalls elsewhere

Most catalogs are technically reachable by an agent and practically unbuyable. Four things are usually in the way, and none of them is in the way here.

• The product is digital. There is no address to collect, no shipping to quote and no delivery window to promise. An eSIM is provisioned the moment payment settles, which removes most of what makes an agent purchase risky for a seller.
• The credential is self-serve. Registration is an endpoint, not an email thread. That is only safe because the self-serve scope settles prepaid, so there is nothing to charge back and no reason to vet anyone before letting them buy.
• The price is frozen, not guessed. Retail is live and multi-currency, so a quote that drifts between reading and paying is a real failure. Every session locks its prices, and the total is rebuilt from our catalog at settlement rather than read from what the client sent.
• The catalog is open. The feed needs no key, publishes structured attributes rather than prose, and every page on this site is also available as Markdown. An agent comparing options does not have to scrape a storefront to do it.

What your user actually receives

A working eSIM, not a voucher to redeem later. The order returns an activation profile the phone installs in a tap, plus a QR code for devices that prefer scanning. It works on the same networks and carries the same coverage as a plan bought on this site, because it is the same plan. Data usage stays checkable afterwards, and a plan can be topped up without changing the eSIM.

What we are building next

Stated plainly, because a roadmap that reads like a feature list is how you end up trusting a page that was describing an intention. None of the following has shipped.

• A public MCP server for buyers. The Model Context Protocol server we run today is internal, scoped to support staff. The buyer-facing one, browse plans, price a trip, purchase and check usage, is the foundation everything below sits on, so it is first.
• A SimFuse app in ChatGPT. Apps in ChatGPT are built on an MCP server and submitted for review, so this follows the server rather than replacing it. It is the reason the MCP work is prioritised over adding a fifth protocol.
• A Claude connector. The same MCP server, listed as a connector, so a user can add SimFuse to their assistant and buy a plan mid-conversation. One server, two front doors.
• Card settlement for approved platforms. Self-serve keys settle in cryptocurrency, which is what makes issuing them without review defensible. Vetted platforms that need card settlement can already ask, and the handler is declared for the day the rails open to us.

Here for a phone, not an API

Then none of the above matters. Pick a destination, pay, and the eSIM installs before you have finished packing. Browse plans by country