Blocknative alternatives

Blocknative publishes a probability-of-inclusion gas oracle that emits EIP-1559 tiered predictions (70, 80, 90, 95, 99 percent confidence) for Ethereum and Polygon, served from a no-key endpoint `?chainid=<N>`. The architecture is deliberate: an inclusion-confidence oracle over-predicts to guarantee landing, while a percentile tracker built on `eth_feeHistory` hugs the realized number by construction. Both choices have implications for a wallet or swap router picking the value to suggest to a user, which is what this benchmark surfaces. The harness polls each oracle at its tier-tolerant cadence (Blocknative every 12 seconds per chain), buffers the predicted priority fee with the predicted block height, and when that block is mined pulls the full block via `eth_getBlockByNumber(.., true)` on the chain's PublicNode RPC. Realized percentiles are computed from actual `maxPriorityFeePerGas` values across every included transaction, and the absolute error per (oracle, tier, chain) lands on both a gauge and a histogram. The table ranks on the p99 gap over 24 hours (the worst 1 percent of blocks) because at current fee levels the typical-minute gaps are fractions of a micro-gwei apart, while gas spikes are where wrong predictions actually cost money. A covered-rate column shows the share of time each prediction sat at or above the realized p50, the inclusion-side risk an absolute gap cannot show. Coverage is Ethereum and Polygon. Avalanche C-Chain was dropped because its auto-tuning fee market drives priority to zero across all oracles; BNB and OP-Stack L2s are excluded for structural reasons. The cohort competing with Blocknative includes PublicNode `eth_feeHistory`, Owlracle (multi-oracle aggregator on a 60-second free quota) and Etherscan v2's free tier.