Citadel MCP server

Historical memory results and configurations

Quick Start

For semantic memory through MCP, install uv and pull the local embedder and optional cross-encoder reranker:

uvx citadeldb-mcp pull e5-large
uvx citadeldb-mcp pull ms-marco-minilm

Set CITADELKEY to your vault passphrase (export CITADELKEY="your-passphrase" on macOS/Linux or $env:CITADEL_KEY = "your-passphrase" in PowerShell), then start:

uvx citadeldb-mcp --db memory.cdl --embedder e5-large --reranker ms-marco-minilm

The server communicates over stdio. See MCP for client configuration. Model downloads do not need a vault key; serving does.

Memory (Python)

Install the published package with pip install citadeldb. See the Python source-build and semantic-memory guide. Embedders implement embedwithcancel(texts, cancel_token) and check cancellation between bounded batches. Local Candle models require the candle-embed build feature.

Memory (Rust)

Uses citadeldb and citadeldb-mem with the candle-embed feature. This example loads e5-large and a local cross-encoder reranker. Other presets or a custom Embedder are supported.

use std::sync::Arc;
use citadel::DatabaseBuilder;
use citadel_mem::{AtomInput, CandleEmbedder, CrossEncoder, MemoryEngine, RecallQuery, RerankStrategy};

// Encrypted store (per-atom keys enable cryptographic forgetting)
let db = DatabaseBuilder::new("memory.db")
    .passphrase(b"secret")
    .enable_region_keys(true)
    .create()?;
let mem = MemoryEngine::open(Arc::new(db))?;

let embedder = Arc::new(CandleEmbedder::e5_large("/path/to/e5-large")?);
mem.create_encrypted_region("chat", embedder)?;
mem.set_reranker(
    Arc::new(CrossEncoder::ms_marco_minilm_l6("/path/to/ms-marco-minilm")?),
    RerankStrategy::default(),
);

// Remember raw turns (no LLM)
mem.remember("chat", AtomInput::new("fact", "Alice's cat is named Mochi"))?;
let berlin = mem.remember("chat", AtomInput::new("fact", "Alice lives in Berlin"))?;

Shortened. The full README is on GitHub.