This gist lists known "chain indexers" and related tools and technologies, eg. software components that are able to "follow the chain" and possibly index current or historical data.
- Oura (less of an indexer and more a building block) (Rust) https://github.com/txpipe/oura
- Scrolls (Rust) https://github.com/txpipe/scrolls
- Ogmios (also not really an indexer and more a node-interface) (Haskell, REST) https://ogmios.dev/
- Carp (builds on Oura, TS, Postgres) https://github.com/dcSpark/carp
- Marconi (Haskell) https://github.com/input-output-hk/marconi
- DB-Sync (Haskell, Postgres) https://github.com/input-output-hk/cardano-db-sync
- Kupo (Haskell, sqlite) https://cardanosolutions.github.io/kupo/#section/Overview
- marlowe-chain-sync (Haskell) https://github.com/input-output-hk/marlowe-cardano/tree/main/marlowe-chain-sync A specialised indexer for use with Marlowe runtime
- probably supersedes Marlowe-ici (Haskell) https://github.com/bwbush/marlowe-ici Has not had a commit in 10 months, probably stale?