🔏 HTTP-402 Facilitator

https://latinum.ai Latinum Tutorial

This project provides two stateless validators ("facilitators") for processing cryptographically verifiable payments used by Multi-Agent Commerce Protocol (MCP) tools:

1. Solana Facilitator – validates signed Solana transactions
2. Base Facilitator – validates signed Ethereum L2 (Base) transactions

Both facilitators are exposed via a unified endpoint: /api/facilitator.

If you have questions or need help, contact us at dennj@latinum.ai.

📦 Prerequisites

• Node.js ^18.x or higher (nvm recommended)
• npm or pnpm

🚀 Install & Run

1. Install dependencies

npx npm-check-updates -u
npm install
# or
pnpm install

2. Start the server

npx nitro dev

Server runs at: http://localhost:3000/

🔀 Unified Facilitator Endpoint

🔁 POST /api/facilitator

The payload must include a chain field set to either solana or base, and corresponding transaction metadata.

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🌉 Base Facilitator (Ethereum L2: Base)

🧾 Request Payload

{
  "chain": "base",
  "signedTransactionHex": "<hex string>",
  "expectedRecipient": "0xRecipientAddress",
  "expectedAmountWei": "50000000000000000"
}

✅ Response

{
  "allowed": true,
  "txHash": "0x...",
  "type": "eth" | "token"
}

🧪 Example (cURL)

curl -X POST http://localhost:3000/api/facilitator \
  -H "Content-Type: application/json" \
  -d '{
    "chain": "base",
    "signedTransactionHex": "0xABC123...",
    "expectedRecipient": "0x123abc...",
    "expectedAmountWei": "50000000000000000"
  }'

⚙️ Solana Facilitator

🧾 Request Payload

{
  "chain": "solana",
  "signedTransactionB64": "<base64 string>",
  "expectedRecipient": "RecipientSolanaAddress",
  "expectedAmountLamports": 50000
}

✅ Response

{
  "allowed": true,
  "txid": "3Xyz..."
}

🧪 Example (cURL – Localhost)

curl -X POST http://localhost:3000/api/facilitator \
  -H "Content-Type: application/json" \
  -d '{
    "chain": "solana",
    "signedTransactionB64": "ABC123...",
    "expectedRecipient": "3BMEwjrn9gBfSetARPrAK1nPTXMRsvQzZLN1n4CYjpcU",
    "expectedAmountLamports": 50000
  }'

🌐 Example (cURL – Remote Host)

curl -X POST https://facilitator.latinum.ai/api/facilitator \
  -H "Content-Type: application/json" \
  -d '{
    "chain": "solana",
    "signedTransactionB64": "ABC123...",
    "expectedRecipient": "3BMEwjrn9gBfSetARPrAK1nPTXMRsvQzZLN1n4CYjpcU",
    "expectedAmountLamports": 50000
  }'

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Let us know if you'd like to contribute, suggest improvements, or report issues.

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