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Documentation Index

Fetch the complete documentation index at: https://docs.prudra.dev/llms.txt

Use this file to discover all available pages before exploring further.

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MPP payments

MPP (Monetization Payment Protocol) is an IETF Internet Draft that uses standard HTTP authentication headers to carry payment credentials. Unlike x402, where the agent signs off-chain and the server settles, MPP requires the agent to send a real on-chain transaction first, then prove it by passing the transaction hash to the server. MPP settles on the Tempo blockchain using USDC.e. It uses the standard WWW-Authenticate and Authorization HTTP headers, making it compatible with standard HTTP authentication libraries.

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The challenge and response headers

Challenge (in 402 response): 
WWW-Authenticate: Payment
  id="ch_abc123",
  realm="your-api.com",
  method="tempo",
  intent="charge",
  request="eyJhbW91bnQiOiIxMDAwMCI..."
The request field is a base64url-encoded JSON object containing payment details (amount, recipient address, chain ID). The id field is an HMAC-SHA256 of all challenge parameters — used to verify the challenge wasn’t tampered with. Agent response (in re-submission): 
Authorization: Payment eyJpZCI6ImNoX2FiYzEyMyIsInR4SGFzaCI6IjB4YWJjLi4uIiwiZnJvbSI6IjB4QWdlbnQuLi4iLCJjaGFpbklkIjo0MjE3fQ==
The Authorization header value is a base64url-encoded JSON credential: 
{
  "id": "ch_abc123",
  "txHash": "0xabc...",
  "from": "0xAgentWallet...",
  "chainId": 4217
}

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When to use MPP

ScenarioRecommendation
Agents on Tempo using USDC.eMPP or dual-protocol
Multi-step workflows (sessions)MPP (session payments are MPP-only)
Maximum compatibilityDual-protocol (both x402 and MPP)
Base + USDC agentsx402 instead
MPP is required for session payments. If you need one payment to cover a multi-step workflow, use MPP.

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Tokens and chains

MPP currently supports:
TokenChainChain ID
USDC.eTempo4217
USDC.eTempo testnetSee testnet config

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Session payments

MPP supports session payments — one payment covers an entire multi-step workflow. After the first payment, the server issues a session ID. Subsequent requests include the session ID and skip payment verification, all accumulating results in the same vault. See Session payments for the full setup.

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Tempo chain specifics

Tempo uses Simplex Consensus — no block reorganisations. Prudra requires only 1 confirmation before considering a Tempo transaction settled. This means MPP payment latency is typically under 2 seconds from the agent’s transaction to the server’s 200 response.