cel-memory-postgres

PostgreSQL + pgvector memory backend for AI agents. Implements cel-memory's MemoryProvider trait with hybrid vector + full-text retrieval.

Status: v0.1.0 starter — Phase 0–1: connect/migrate, write/get, hybrid retrieve, sessions, stats. Summarization, aging, export, and bulk mutations return NotImplemented until later phases (see BACKENDS.md).

Purpose

Use cel-memory-postgres when you need durable agent memory in a shared PostgreSQL deployment — multi-tenant services, team backends, or production hosts that already run Postgres. Swap it in wherever code holds Arc<dyn MemoryProvider> today (e.g. beside cel-memory-sqlite).

Requirements

• PostgreSQL 14+ with the pgvector extension
• Embedding width 384 (matches MockEmbedder / bge-small)

Example

use std::sync::Arc;
use cel_memory_postgres::{MockEmbedder, PostgresMemoryProvider};

let provider = PostgresMemoryProvider::connect(
    "postgres://postgres:postgres@localhost:5432/cel_memory",
    Arc::new(MockEmbedder::new()),
).await?;
// Use as cel_memory::MemoryProvider — same trait as BasicMemoryProvider.

Run the complete example (requires CEL_MEMORY_POSTGRES_URL):

CEL_MEMORY_POSTGRES_URL=postgres://postgres:postgres@localhost:5432/cel_memory \
  cargo run --example basic

Testing

Integration tests use the same URL:

docker run -d --name cel-pg-test \
  -e POSTGRES_PASSWORD=postgres \
  -e POSTGRES_DB=cel_memory_test \
  -p 54329:5432 \
  pgvector/pgvector:pg16

export CEL_MEMORY_POSTGRES_URL=postgres://postgres:postgres@localhost:54329/cel_memory_test
cargo test

What's included (Phase 0–1)

• PostgresMemoryProvider::connect — pool + sqlx migrations
• write / get / write_batch
• Hybrid retrieve — pgvector cosine distance + tsvector FTS, fused with RRF
• Session lifecycle — open_session, close_session, rename_session, get_session, list_sessions
• stats

Roadmap

License

Apache-2.0