x402 vs Universal Commerce Protocol (UCP)
They sit at the same step and overlap in purpose; the fields above are the basis for choosing.
| x402 | Universal Commerce Protocol UCP | |
|---|---|---|
| Lifecycle step | 7 Pay: Settle the bill | 7 Pay: Settle the bill |
| Answers | How can an HTTP client pay per-request or per-resource, in stablecoins, without accounts, API keys, or signup? | Can an agent discover a business's commerce capabilities, build a cart, and check out interoperably across shopping, lodging, and food ordering? |
| Governed by | x402 Foundation, a Series of LF Projects, LLC (Linux Foundation); operational launch announced 2026-07-14; Executive Director Michael Hursta from 2026-10-01; 50+ members | Domain Tech Councils (DTC) per vertical — Shopping Tech Council and Food Tech Council seated — under an overall Governing Council (GC); DTC seats held by Google, Shopify, Etsy, Meta, Amazon, Microsoft, Target, Stripe, Salesforce, Wayfair, Square, Toast, DoorDash, Uber Eats |
| Status (issuer's words) | Open, neutral standard for internet-native payments | Open standard; specification expanding beyond Shopping into Lodging and Food |
| Version | x402 protocol specification v2, transports-v2/http.md | v2026-08-25 (2026-08-25) |
| Form / transport | HTTP header | well-known file |
| Found at | none — signalled per-request via the 402 status code, not a fixed well-known path | /.well-known/ucp |
| Implementation | multi-implementation — x402 Foundation (x402.org live dashboard) | multi-implementation — UCP project (ucp.dev launch-partner list) |
| Evidence | 5 verified | 5 verified, 1 reported |
| Primary use case | Accept payments from agents | Let agents buy on behalf of a person |
| Last verified | 2026-10-23 (current) | 2026-10-23 (current) |
| Specification | https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md | https://ucp.dev/documentation/core-concepts/ |
When to use which
- Choose x402 when your question is “How can an HTTP client pay per-request or per-resource, in stablecoins, without accounts, API keys, or signup?” and you accept its maturity: status "Open, neutral standard for internet-native payments", implementation multi-implementation (x402 Foundation (x402.org live dashboard)).
- Choose Universal Commerce Protocol when your question is “Can an agent discover a business's commerce capabilities, build a cart, and check out interoperably across shopping, lodging, and food ordering?” and you accept its maturity: status "Open standard; specification expanding beyond Shopping into Lodging and Food", implementation multi-implementation (UCP project (ucp.dev launch-partner list)).
Read the full articles
- x402: How can an HTTP client pay per-request or per-resource, in stablecoins, without accounts, API keys, or signup?
- Universal Commerce Protocol: Can an agent discover a business's commerce capabilities, build a cart, and check out interoperably across shopping, lodging, and food ordering?