MPP

MPP challenges are usually expressed through WWW-Authenticate and retried with an authorization credential.

Agent summary

• mpp charge challenges map to a single paid retry.
• mpp-session challenges map to capped repeated-call authorization.
• Pay selects compatible Solana charge challenges based on wallet and network.
• Do not parse or construct MPP credentials manually in docs examples.

Charge flow

pay --sandbox curl https://payment-debugger.vercel.app/mpp/quote/AAPL

Session language

Use "session payments" or "capped repeated calls" for MPP sessions. Avoid "streamed payments" unless the API and payment contract actually stream value or usage state.