LemonMemory

Durable memory for agents: what an agent did, written down and searchable later.

lemon_memory is one of the packages that make up the Lemon agent platform. It is usable on its own — its only Lemon dependency is lemon_core.

What is in it

Module	Purpose
`LemonMemory.Document`	The record every provider reads and writes: content, scope, metadata, timestamps
`LemonMemory.Store`	SQLite-backed store with full-text search; the built-in durable backend
`LemonMemory.Provider`	Behaviour for a searchable memory backend
`LemonMemory.Providers`	Fan-out registry — queries every registered provider, isolates failures and timeouts
`LemonMemory.Providers.Local`	The built-in provider over `LemonMemory.Store`
`LemonMemory.Ingest`	Writes finished runs into memory, invoked from the store's finalize-run hook
`LemonMemory.Safety`	Redaction and size limits applied before anything is persisted
`LemonMemory.SessionSearch`	Scoped search across sessions, agents and workspaces
`LemonMemory.TaskFingerprint`	Stable fingerprints for recognising repeated work

mix lemon.memory inspects and searches the store from the command line.

Installation

def deps do
  [{:lemon_memory, "~> 0.1"}]
end

SQLite (exqlite) is a hard dependency here, unlike in lemon_core where it is optional: a durable store is this package's reason to exist.

Adding a provider

Implement LemonMemory.Provider and register it at boot:

LemonMemory.Providers.register_provider(%{
  id: "vector",
  module: MyApp.VectorMemory,
  label: "Vector store",
  timeout_ms: 2_000
})

Searches then fan out to it alongside the local store. Read the behaviour's moduledoc first — it documents the contract in prose, including the rules that are easy to get wrong (search/2 returns a bare list, must not raise on user input, and must ignore options it does not recognise).

Verify your provider against the platform's compliance suite:

defmodule MyApp.VectorMemoryTest do
  use LemonPlatformTest.ProviderCase, provider: MyApp.VectorMemory
end

Configuration

# `:path` is a directory; memory.sqlite3 is created inside it.
config :lemon_memory, LemonMemory.Store, path: "/var/lib/my_app/store"

LemonMemory.Application starts Providers always, and Store plus Ingest when SQLite is available.