cel-memory-sqlite

SQLite-backed local memory for AI agents. Implements cel-memory's MemoryProvider trait with single-file storage, FTS, and vector search through sqlite-vec.

Status: v0.1 — implements the full MemoryProvider surface: writes, sessions, hybrid (vector + FTS + recency) retrieval fronted by a TTL+LRU cache, summarization and daily/rule-week rollups (via an injected summarizer), aging sweeps, export, and stats. re_embed_all is the one method still unimplemented.

What's in this crate

SqliteMemoryProvider — MemoryProvider impl backed by SQLite (one file, no separate process).
Embedder trait + MockEmbedder (always available).
FastEmbedEmbedder behind the fastembed feature — local ONNX runtime + bge-small-en-v1.5 (~130 MB model download).
Schema migrations for memory_chunks, memory_vec (sqlite-vec virtual table), memory_fts (FTS5), sessions, access log, eviction log.
sqlite-vec extension loaded at connection open; the memory_vec virtual table is available without extra setup.

Design

Single SQLite file. One file to back up, encrypt, ship to compliance. No separate vector daemon, no second process to manage.
Brute-force vector scan up to ~1M chunks per user. sqlite-vec is fast on Apple Silicon (5–30 ms at typical personal-memory scale). HNSW is a drop-in upgrade when sqlite-vec ships it.
Hybrid retrieval: vector + FTS + recency, weighted per RetrievalProfile, fused with reciprocal-rank fusion and fronted by a short-TTL LRU cache.
Governance-first. Every write consults the optional MemoryWriteHook from cel-memory — a rule engine can redact or veto.

Example

use std::sync::Arc;
use cel_memory_sqlite::{MockEmbedder, SqliteMemoryProvider};

let provider = SqliteMemoryProvider::open(
    "memory.sqlite",
    Arc::new(MockEmbedder::new()),
).await?;
// Use as cel_memory::MemoryProvider — same trait as BasicMemoryProvider.

Run the complete example:

cargo run -p cel-memory-sqlite --example basic

Features

fastembed — enables FastEmbedEmbedder for local embeddings. Off by default to avoid the 130 MB model download in dev workflows.

License