AgentAnswers v3.6.0-realx402 — APIs agents pay for (x402)

Endpoints (POST JSON):
- /extract  $0.005 — {"url": "https://..."} → title, prices, text
- /verify   $0.20  — {"claim": "...", "url": "https://..."} → verdict + evidence
- /research $0.50  — {"question": "...", "depth": "quick|deep"} → cited report
- /backtest $1.00  — {"symbol": "BTCUSDT|ETHUSDT|SOLUSDT", "strategy": "sma_20_50|macd_8_21_5|core70_trend50"} → honest backtest
- /dashboard — public live stats + pricing + backtest table (HTML, for humans + agents)

x402:
- Free tier: per-IP (FREE_PER_IP env, default 50/day; set 10 in production). No key needed.
- After free tier, server returns 402 with x402 v2 requirements (USDC on Base).
- Send header PAYMENT-SIGNATURE: <base64 v2 PaymentPayload> with signed EIP-3009 authorization.
- REAL mainnet: payments verified + settled via CDP facilitator (USDC on Base, payTo set).

Discovery: GET /llms.txt, /.well-known/agent-card.json, /openapi.json, /health, /dashboard
MCP: POST /mcp (JSON-RPC: initialize, tools/list, tools/call), GET /sse, POST /messages
Free tier: per-IP (FREE_PER_IP env, default 50/day). Real x402: set FACILITATOR_URL + PAY_TO + CDP_API_KEY_ID + CDP_API_KEY_SECRET env.
Example: curl -X POST http://localhost:8000/extract -H 'content-type: application/json' -d '{"url":"https://example.com"}'