Paid services on Base matching “osrm”

OSRM driving route (keyless). POST {coordinates|from+to}. Unpaid empty → 402; after settle empty/invalid → 400 charged:false. Soft disclose mbta-routes / tfl-line-status (transit adjacency only).

Current chain tip block height via eth_blockNumber. Returns decimal block number and hex. Works on Base (default) or Ethereum via ?network=eth. Deterministic on-chain read via public RPC.