2D-Filtermaps in Reth

Duration: NaN:NaN:NaN

Speaker: Rangrej Ayush

Type: CLS - EPF Talk

Expertise: Some familiarity with the topic

Event: Devcon

Date: Nov 2026

eth_getLogs becomes increasingly expensive as chain history grows, and client-side indexing is one way execution clients can reduce the amount of history scanned for log queries. Geth already ships FilterMaps, a 2-D probabilistic log index, but reproducing it in another client requires matching much more than just the high-level data structure. This presentation will cover the design of bringing that approach to Reth. Matching Geth's value-index space, storing filter-map rows efficiently in MDBX, building the index incrementally through a background service, handling reorgs and bounded history, and integrating it with the existing RPC path while falling back to bloom scans for unindexed ranges.