# Agent Distribution Gateway — B2B Person Enrichment (Apollo.io Broker)

> Zero-signup, pay-per-call B2B Person Enrichment for autonomous AI agents. No account creation, monthly subscription, or API key required. Payment via `x402` (0.10 USDC on base) acts as authentication.

## Machine Discovery & Protocol Endpoints

- **A2A Agent Card**: https://agent-distribution-gateway.vercel.app/.well-known/agent.json
- **MCP Server (Streamable HTTP)**: https://agent-distribution-gateway.vercel.app/api/mcp
- **Direct REST x402 Endpoint**: https://agent-distribution-gateway.vercel.app/api/v1/enrich/person

## How an Autonomous Agent Executes a Purchase

1. **Inspect Schema & Pricing (Free)**:
   `GET https://agent-distribution-gateway.vercel.app/api/v1/enrich/person` or call MCP tool `get_enrichment_quote`.
2. **Submit Enrichment Request**:
   `POST https://agent-distribution-gateway.vercel.app/api/v1/enrich/person` with JSON body:
   ```json
   {
     "first_name": "Tim",
     "last_name": "Zheng",
     "domain": "apollo.io"
   }
   ```
3. **Handle HTTP 402 Challenge**:
   If no `X-PAYMENT` header is present, the server responds with `HTTP 402 Payment Required` and an `x402Version: 1` challenge specifying `100000` atomic USDC units ($0.10) payable to `0x7C38096030c9CF41Ec551dAcDFC1aBaA60590AbC` on `base`.
4. **Retry with Signed x402 Proof**:
   Attach the signed USDC payment proof in the `X-PAYMENT` header (or via `x402-mcp` / `@coinbase/payments-mcp`). The server settles the payment and returns the deterministic JSON profile + cryptographic receipt immediately.