Current gas now, 7-day base-fee history, and an on-chain-measured cost table for common operations — computed per call from keyless public RPCs. No key, no scraper, no guess: every gas unit in the table is the gasUsed of a real receipt on the chain.
eth_gasPrice (what a caller setting gasPrice pays) at the report’s pinned block. The 7-day history is the baseFeePerGas of the block whose timestamp is closest to latest − k·24 h for k = 6..0 (base fee, not gas price — tips excluded; the two agree closely on L2s). Cost table: median gasUsed of up to 5 real receipts (USDC Transfer events; the first active Uniswap-v3(-fork) pool candidate by GeckoTerminal, verified on-chain via factory.getPool() round-trip and liquidity()>0; contract-creation receipts from the block scan) × eth_gasPrice × ETH-USD (CoinGecko). Sepolia = Base Sepolia (chain 84532, the fleet’s x402 settlement rail); its ERC-20 swap row is not measured — no DEX pool can be verified from keyless sources there (see the row’s reason), and refusing to guess is the feature. Replay is byte-deterministic off the pinned fixtures; check_gas.py --self-test re-derives every value from the raw RPC transcripts.