Component Library

Estoria orchestrates the lifecycle of aggregates, but it relies on a set of vendor-specific components to provide the underlying storage features. These components include:

Event Stores, for storing events.
Checkpoint Stores, for persisting projection progress.
Snapshot Stores, for storing snapshots of aggregate state.
Aggregate Caches, for caching aggregate state in memory or in a distributed cache.

Officially Supported Implementations

These components are maintained by the Estoria project. They are tested against each Estoria release and subject to a standard suite of acceptance tests.

Event Stores

Event Store	Driver	Global Reads	Stream Deletion	Outbox	Details
KurrentDB	KurrentDB-Client-Go	Yes	No	—	Streams map closely to Kurrent streams.
MongoDB	mongo-go-driver	Yes	Yes	Yes	A single collection for all events, or events partitioned across collections by a configurable selector.
PostgreSQL	pgx	Yes	Yes	Yes	Uses a single table for all events.
SQLite	modernc.org/sqlite	Yes	Yes	—	Uses a single table for all events; no CGO required.

Global Reads and Stream Deletion are the event store’s optional capabilities. KurrentDB’s “No” for stream deletion is deliberate: its native delete semantics cannot honestly satisfy the interface’s contract, so the store does not claim it (the rationale is in its README). Outbox links to the store’s companion transactional outbox package, where one exists.

Checkpoint Stores

Checkpoint stores persist projection progress — the global position a projection has processed through, keyed by versioned projection ID.

Checkpoint Store	Driver	Details
MongoDB	mongo-go-driver	One document per projection; reads pinned to the primary, writes must be acknowledged.
PostgreSQL	pgx	A single table, one row per projection.
SQLite	modernc.org/sqlite	A single table, one row per projection; no CGO required.

Snapshot Stores

Coming soon.

Backend	Driver

Aggregate Caches

Aggregate Cache	Type	Driver
bigcache	In-Memory	https://github.com/allegro/bigcache
freecache	In-Memory	https://github.com/coocood/freecache
Redis	Distributed	https://github.com/go-redis/redis
Valkey	Distributed	https://github.com/valkey-io/valkey-go