Agent payment protocols, compared
The signature artifact of this reference: a side-by-side matrix of the protocols the registry tracks. Sort by any column; filter to narrow the set.
Legendstrong strongmoderate moderateweak weak— not applicableunverified unverified draft
13 of 13 protocols
| A2A | communication | framework | — | — | — | live | 2026-09-02 |
|---|---|---|---|---|---|---|---|
| ACP | execution | framework | — | strong | moderate | unverified | 2026-09-23 |
| AMP | execution | hybrid | yes | strong | moderate | live | 2026-09-14 |
| AP2 | authorization | framework | — | strong | moderate | live | 2026-09-03 |
| AP4M | execution | card-rail | yes | moderate | strong | live | 2026-09-14 |
| ERC-4337 | custody | primitive | — | — | — | live | 2026-09-02 |
| MPP | execution | hybrid | yes | moderate | strong | beta | 2026-09-03 |
| P3P | execution | hybrid | yes | strong | moderate | live | 2026-09-03 |
| TAP | authorization | card-rail | — | strong | moderate | live | 2026-09-14 |
| UAP | authorization | framework | — | strong | weak | unverified | 2026-09-14 |
| UCP | communication | framework | — | strong | moderate | unverified | 2026-09-23 |
| a402 | execution | onchain | no | weak | moderate | proposed | 2026-09-02 |
| x402 | execution | onchain | no | moderate | strong | live | 2026-09-03 |
How to read this
Rows are protocols; columns are comparable attributes. Fit chips show suitability for direct-to-consumer (D2C) and business-to-business (B2B) agent payments. A muted em-dash — means the attribute does not apply to that protocol's layer — for example, a communication or authorization layer neither settles value nor has a meaningful "reversible" property. Click a column header to sort. Draft rows are flagged unverified and are excluded from the structured-data claims exposed to machines.