Backend: Memory

The default in-process store backend.

The memory backend is the default for all five store traits. It stores everything in HashMaps behind RwLocks, with no persistence across restarts. It is used in tests and as the default for Extensions::default().

Implementations

Type	Trait	Storage
MemorySessionStore	SessionStore	HashMap<Uuid, Session> + Vec<MessageRecord>
MemoryEmbeddingStore	EmbeddingStore	Vec<EmbeddingRecord> (brute-force search)
MemoryExecutionStore	ExecutionStore	HashMap<Uuid, Vec<ToolExecution>>
MemoryArtifactStore	ArtifactStore	HashMap<Uuid, Artifact>
MemoryRunStore	RunStore	HashMap<RunId, RunRecord> + Vec<RunEventRecord>

Characteristics

• No persistence — data is lost on restart.
• No network — no connection strings, no auth, no TLS.
• Brute-force search — MemoryEmbeddingStore::search computes cosine similarity against every stored vector. Fine for <10k vectors.
• Single Mutex per store — MemoryRunStore uses a single Mutex for atomic event append + projection update.

When to use

• Tests and examples.
• Local development.
• Single-process deployments where persistence is handled externally (e.g. the caller serialises sessions).

When not to use

• Multi-process deployments.
• Production with durability requirements.
• More than ~10k embedding vectors (use Qdrant).

See also

• Storage Overview — the full matrix.