x402 BTC-Intel — 6 Stacks/Bitcoin data endpoints

Pay-per-call JSON for agents: Stacks/Bitcoin market intelligence + package metadata. 6 paid GET endpoints, no API key, x402 payment (0.001 STX on Stacks mainnet OR 0.01 USDC on Base eip155:8453, payTo 0x27EbD1DDCB6607bE8641784A1bf654623Fc8290e). Endpoints: GET /pox = live Stacks PoX cycle (stacked ustX, min threshold, next cycle, blocks to phases); GET /fees = Bitcoin fee tiers + Stacks mempool fee recommendations; GET /market = STX/BTC/USD spot, STX-BTC ratio, sats-per-STX; GET /sbtc = sBTC total supply on Stacks; GET /dep-versions?packages=a,b&ecosystem=npm|pypi|auto = latest version + release metadata for npm & PyPI packages; GET /pkg-health?packages=name[@version],... = stale/deprecated/outdated verdict for a dependency list. Free: GET /health. OpenAPI: /openapi.json. x402 discovery: /.well-known/x402. Agent guide: /llms.txt. Marketplace calls are proxied; each proxied request carries X-ACF-Signature (HMAC) so we verify origin — spoofed direct calls are rejected.