mempill-sqlite

SQLite persistence adapter for mempill (topology-a).

See the repository README for the full architecture, quick start, and invariants.

What this crate provides

SqlitePersistenceStore — impl PersistencePort backed by a single rusqlite connection.
DefaultEngine — type alias for EngineHandle<SqlitePersistenceStore, NoOpOracle, NoOpVector>.
open_default(path) — open a file-backed engine at the given path.
open_default_in_memory() — open an ephemeral in-memory engine (tests, MCP sessions).

Usage

use mempill_sqlite::open_default_in_memory;
use mempill_core::application::{IngestClaimRequest, QueryMemoryRequest};
use mempill_types::{AgentId, Cardinality, Confidence, Criticality, ExternalKind, ProvenanceLabel};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let engine = open_default_in_memory()?;
    let agent = AgentId("my-agent".into());

    let resp = engine.ingest_claim(IngestClaimRequest {
        agent_id: agent.clone(),
        subject: "user".into(),
        predicate: "city".into(),
        value: serde_json::json!("Berlin"),
        provenance: ProvenanceLabel::External(ExternalKind::UserAsserted),
        cardinality: Cardinality::Functional,
        valid_time: None,
        confidence: Confidence { value_confidence: 0.95, valid_time_confidence: 0.0 },
        criticality: Criticality::Medium,
        derived_from: vec![],
    }).await?;

    println!("{:?}", resp.disposition);
    Ok(())
}

PRAGMA contract

Applied at connection open, before any DML:

PRAGMA journal_mode = WAL;
PRAGMA synchronous  = FULL;   -- mandatory: WAL+NORMAL can lose writes on power loss
PRAGMA foreign_keys = ON;

When to use SQLite vs PostgreSQL

Single-agent deployment, embedded library, tests, MCP sessions → SQLite (this crate)
Multi-agent shared database, production service → mempill-postgres

Both adapters implement the same PersistencePort trait and are proven behaviorally identical by the shared conformance harness.

License