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: v0.2.0 on crates.io — 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, stats, and bulk re-embed.

Purpose

Use cel-memory-sqlite when you want a local, embeddable MemoryProvider backend without running a separate database or vector service. It is designed for agents, CLIs, desktop apps, local servers, and test harnesses that need durable memory in one SQLite file.

What's Included

• SqliteMemoryProvider — MemoryProvider impl backed by SQLite (one file, no separate process).
• Embedder / MockEmbedder — re-exported from cel-memory (since 0.2.0).
• 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 service, 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 --example basic

Features

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

Upgrading from 0.1.x

Depends on cel-memory 0.2.0; import Embedder from cel_memory or keep using the sqlite re-export. See the 0.2 migration guide.

License

Apache-2.0