# MPP: which products take Machine Payments from AI agents 2 of 151 products we drove offer MPP. What the protocol is, which products take it, and how to let agents pay you by card or stablecoin. Source: https://agentdrives.com/standards/mpp · Updated 2026-10-24 · as data: https://agentdrives.com/standards/mpp.json · licence CC BY 4.0 The Machine Payments Protocol is an open standard for agentic commerce: a product asks for payment with a 402 and takes it by card or stablecoin, request by request. ## The numbers From our drives of 151 products, 1–24 Oct 2026 (https://agentdrives.com/data/facts?via=md): - Offer MPP: 2 of 151 (https://agentdrives.com/data/facts?via=md#pay.mpp) - Offer any agent payment: 26 of 151 (https://agentdrives.com/data/facts?via=md#pay.offers_rail) ## What it is MPP's core is an IETF draft, draft-httpauth-payment-01 (2026-09-09, active) [1]. A server asks for payment with a 402 and a `WWW-Authenticate: Payment` header; [2] the agent sends a payment credential, and a successful answer carries a `Payment-Receipt` [2] header. Stripe takes MPP (cards and stablecoins), x402 (stablecoins) [3]. [3] The agent pays, and Stripe settles to the seller's balance. [3] ## How many products offer it 2 of 151 products we drove offer MPP, seen or paid. 26 of 151 offer at least one way for an agent to pay. ## How to add it 1. **Answer paid routes with a payment challenge.** A 402 with `WWW-Authenticate: Payment`. [2] Stripe's machine payments do the challenge and the settling for you. [3] 2. **Publish your prices.** MPP discovery reads your OpenAPI document at `/openapi.json`, [4] with `x-payment-info` on each paid operation. [4] Each paid operation also lists its 402. [5] 3. **Return a receipt.** Send `Payment-Receipt` with each paid answer, so the agent can keep it. [2] [The pay-per-call guide](https://agentdrives.com/fixes/let-agents-pay-per-call) has the rest. ## Check it yourself 1. **Call a paid route without paying.** You want a 402 with a `WWW-Authenticate: Payment` header. ``` curl -si https://example.com/api/paid-route | grep -i -E "^HTTP|www-authenticate" ``` 2. **Check your discovery document.** It should list the paid routes with their price. ``` curl -s https://example.com/openapi.json | grep -c x-payment-info ``` ## Products that offer MPP - [Exa](https://agentdrives.com/tools/exa.md?via=md): L2 Gets in - [Parallel](https://agentdrives.com/tools/parallel.md?via=md): L4 Runs on its own ## Questions **How is MPP different from x402?** Both answer with a 402. MPP uses the HTTP authentication headers and takes cards as well as stablecoins; x402 uses its own headers and stablecoins. **Do I need my own wallet?** Not with Stripe: it settles the payments to your Stripe balance. ## Sources 1. [IETF draft](https://datatracker.ietf.org/api/v1/doc/document/draft-httpauth-payment/) 2. [The Payment HTTP authentication scheme (MPP)](https://www.ietf.org/archive/id/draft-httpauth-payment-01.txt) 3. [Machine payments](https://docs.stripe.com/payments/machine) 4. [MPP payment discovery](https://paymentauth.org/draft-payment-discovery-01) 5. [MPP: discovery](https://mpp.dev/advanced/discovery) ## More standards - [MCP](https://agentdrives.com/standards/mcp.md): A server that turns a product's actions into tools an agent can call. - [llms.txt](https://agentdrives.com/standards/llms-txt.md): A Markdown map of a product's docs, written for language models. - [OpenAPI](https://agentdrives.com/standards/openapi.md): A machine-readable description of every route of an API. - [Web Bot Auth](https://agentdrives.com/standards/web-bot-auth.md): An agent signs each request; a site's bot check can verify who sent it. - [Signed agents](https://agentdrives.com/standards/signed-agents.md): Agents a bot-check vendor has verified, which a site can let through. - [robots.txt for AI agents](https://agentdrives.com/standards/robots-txt-ai.md): The file that tells crawlers and agents which pages to leave alone. - [x402](https://agentdrives.com/standards/x402.md): A 402 answer an agent pays in a stablecoin, request by request.