Agent commerce
x402
An open standard for paying for APIs and content directly over HTTP using the 402 Payment Required status code.
- Status
- Stable, protocol v2; foundation launched July 2026
- Governance
- x402 Foundation (Linux Foundation), contributed by Coinbase
- Sources
- Project siteSpecification
- Latest release (checked daily)
- 2.25.0 on 2026-09-29 · PyPI x402 · all releases
What to know
- A server answers an unpaid request with HTTP 402 and payment terms; the client pays and retries, with no account or API key.
- The Linux Foundation announced the operational launch of the x402 Foundation on 2026-07-14, after Coinbase completed the contribution.
- Premier members include AWS, Cloudflare, Coinbase, Google, Mastercard, Shopify, Stripe and Visa.
- It supports several payment schemes (exact, upto, batch settlement) and extensions such as Bazaar discovery and Sign-In-With-X.
- It is network-neutral and is used for both stablecoin and card-based flows.
When to use it
Use it when agents or programs need to pay per request for an API, data or content without signing up or managing keys.
Related standards
MCP · Model Context ProtocolA2A · Agent2Agent ProtocolSKILL.md · Agent SkillsAGENTS.md · AGENTS.mdACP · Agent Client ProtocolPAP · Personal Agent ProtocolAG-UI · Agent User Interaction Protocol (AG-UI)A2UI · A2UIMCP Apps · MCP AppsTAP · Trusted Agent ProtocolPACT · Personal Agent Consent & Trust Protocol (PACT)ANP · Agent Network ProtocolOASF · Open Agentic Schema FrameworkWebMCP · WebMCPllms.txt · llms.txtAgent Spec · Open Agent Specification
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Reviewed Oct 7, 2026. Spotted something out of date? Email hello@agentatlas.dev.