# ACN Preflight Engine
Base URL: https://preflight.abacore.net

Capabilities:
- bounty_reality_check: GET /v1/bounty?issue_url={github_issue_url}, price USD 0.00, no registration, no email.
- repo_contribution_readiness: POST /v1/repo, price USD 0.10.
- payment_preflight: POST /v1/payment, price USD 0.02.

Paid transport:
- Preferred: x402 v2 exact payment in Base USDC on eip155:8453.
- HTTP: read PAYMENT-REQUIRED from a 402 response, retry with PAYMENT-SIGNATURE, then read PAYMENT-RESPONSE on success.
- MCP: paid tools return x402 PaymentRequired in the tool result; retry with _meta["x402/payment"].
- Legacy direct USDC settlement plus Bearer access token remains available as a fallback.
- No server-side signing key is used for x402 settlement.

Machine-readable contracts:
- OpenAPI 3.1: https://preflight.abacore.net/openapi.json
- A2A Agent Card: https://preflight.abacore.net/.well-known/agent-card.json
- MCP discovery: https://preflight.abacore.net/.well-known/mcp.json
- x402 payment metadata: https://preflight.abacore.net/.well-known/x402
- Self-check proof: https://preflight.abacore.net/agent-readiness.json

Conditions:
- Paid capabilities are published only while a fresh dual-external seven-surface self-check is PASS and the local payment-safety snapshot is fresh.
- If the safety proof is missing, stale, or failing, payment_state is SAFETY_HOLD and paid resources are omitted.
- Payment Preflight is a technical chain-state check, not financial advice.
- Bounty Reality Check uses fresh public GitHub data.