Payments & Protocols
Every paid PayWeave endpoint accepts two payment protocols on the same URL: MPP (the Machine Payment Protocol) and x402 (Coinbase's open HTTP-402 standard). An agent pays with whichever it supports. You don't pick a rail per endpoint, and you don't maintain two integrations.
One URL, a dual 402
When an agent hits a paid endpoint without payment, PayWeave returns a single 402 Payment Required that advertises both protocols at once: the MPP challenge in a WWW-Authenticate: Payment header, and the x402 requirements in the response body's accepts[] array. MPP clients read the header and ignore the body; x402 clients read the body and ignore the header. Both settle to the same merchant wallet.
MPP: Machine Payment Protocol
Tempo's payment standard. The client signs a stablecoin transfer, PayWeave settles it, and the receipt returns in a Payment-Receipt header, all in one retry. Runs on Tempo and Solana. Clients include mppx, @solana/mpp, the Tempo wallet CLI, and Solana Foundation's pay.
x402
Coinbase's open HTTP-402 standard. The payer signs a gasless USDC authorization (EIP-3009 on Base, a co-signed SPL transfer on Solana) and a hosted facilitator (Coinbase CDP) verifies and settles it on-chain, so the payer pays no gas and funds go direct to the merchant. Runs on Base and Solana. Clients include x402-fetch, x402-axios, Coinbase AgentKit / CDP wallets, and AgentCash.
Chains & tokens
| Protocol | Chains | Token |
|---|---|---|
| MPP | Tempo, Solana | USDC (USDC.e on Tempo) |
| x402 | Base, Solana | USDC |
USDC is the common settlement currency. Solana endpoints accept both protocols, so a Solana agent can pay via MPP or x402; Base is x402-only; Tempo is MPP-only.
Fees
The platform fee is an on-chain split baked into MPP charges. Because x402's exact scheme is a single transfer to one recipient, x402 payments settle the full amount direct to the merchant with no on-chain platform cut. See Pricing for details.