OSA MCP Server

OSA Agent Trust Oracle

A working MVP for choosing and verifying agent/API endpoints before purchase.

What it does

• GET /best — ranks matching endpoints by TrustScore, optional intent and max_price.
• GET /score — performs live verification and returns TrustScore + confidence + reason codes.
• GET /history — returns historical snapshots for an endpoint.
• Snapshot persistence instead of only keeping latest state.
• TrustScore includes uptime, latency, price drift, schema drift, payment changes, and transaction evidence.
• Unified ingestion for manual records, MCP Registry-shaped records, and x402/Bazaar-shaped resources.
• Optional x402 v2 payment protection for /best and /score using USDC.
• Bazaar discovery extension metadata when x402 is enabled.

Quick start

npm install
npm test
npm start

Then ingest an endpoint:

curl -X POST http://localhost:4021/ingest \
  -H 'content-type: application/json' \
  -d '{"url":"https://example.com/api","intent":"search","priceUsd":0.01,"transactionEvidence":12}'

Find the best endpoint:

curl 'http://localhost:4021/best?intent=search&max_price=0.05'

x402

Payments are disabled by default so local development is frictionless. To enable them:

cp .env.example .env
export OSA_PAY_TO=0xYOUR_WALLET
export OSA_NETWORK=eip155:84532
export OSA_FACILITATOR_URL=https://x402.org/facilitator
npm start

Use Base Sepolia for testing first. When enabled, /best and /score are protected through the official x402 server packages and expose Bazaar discovery metadata.

TrustScore

Current MVP weights:

• uptime 30%
• latency 20%
• price stability 15%
• schema stability 15%
• payment stability 10%
• transaction evidence 10%

The API also returns confidence separately so a high score with weak evidence is distinguishable from a well-proven endpoint.

Production next steps

Replace JSON persistence with Postgres/Supabase, add scheduled source crawlers, and deploy behind a stable HTTPS origin before turning on mainnet payments.