Crate leviathan 

Leviathan: deep memory for agents over large datasets.

Index JSONL, JSON, CSV or SQLite records into a single SQLite/FTS5 file, then answer questions with a few ranked, cited cards instead of the raw data. A small field mapping (leviathan.toml, CLI flags, or inference) says which fields are the id, title, searchable text, group, date and filters. Use it from the CLI, as an MCP server, or as a library:

use leviathan::{card::CardOptions, query::{SearchRequest, Store}};

let store = Store::open("leviathan.db".as_ref(), CardOptions::default())?;
let hits = store.search(&SearchRequest {
    group: Some("acme".into()),
    query: "login loops after password reset".into(),
    filters: vec![("status".into(), "closed".into())],
    limit: 5,
    fallback: true,
    ..Default::default()
})?;
println!("{}", leviathan::render::search(&hits));

Modules

card

Result cards: the compact, citable view of one record.

config

The field mapping: which parts of a record are its id, title, searchable text, group, date, filters and display fields.

fields

Field paths into JSON records, and the compiled Mapping that turns a record into what the index stores.

index

Build and update the on-disk index.

infer

leviathan init: profile a sample of the data and propose a mapping.

mcp

Minimal Model Context Protocol server over stdio (JSON-RPC 2.0, one message per line). Read-only: every tool is a fixed query shape over the index; there is no SQL passthrough, no file access and no write path. stdout carries protocol messages only; diagnostics go to stderr.

query

Read-only query layer over the index.

render

Compact text rendering. This is what agents read by default, so every line is spent deliberately: scope and counts in the header, one short block per record, and an explicit statement when nothing was found.

source

Record sources: JSONL / NDJSON, JSON arrays, CSV / TSV (each optionally gzip), SQLite tables or queries, and stdin. Every source yields JSON objects; line-oriented formats stream, so inputs far larger than memory are fine.

text

Text helpers shared by the indexer and the query layer.

wrap

leviathan wrap <agent>: print the configuration snippet that registers Leviathan with an agent. It prints; it never edits anyone’s config.

Functions

now_rfc3339

Current UTC time as RFC 3339, without a date-time dependency.