Memory that survives the session.

The problem

AI agents forget everything between sessions. Every conversation starts from scratch. Developers compensate with massive configuration files, copy-pasted context, and fragile prompt engineering. The longer the session, the worse the output gets.

Perlith gives agents a structured memory that lives outside the context window. Facts are stored as plain files. Changes are git commits. Retrieval is fast and precise. Nothing is lost when a session ends.

Quick start

const perlith = require('perlith')

// Initialize an agent
await perlith.initAgent('./memory', 'my-agent')

// Store a memory
await perlith.addMemory('./memory', 'my-agent', {
  layer: 'L1',
  body: 'User prefers dark mode and uses VS Code.',
  tags: ['preferences', 'editor'],
})

// Retrieve relevant memories
const results = await perlith.retrieve(
  './memory', 'my-agent', 'editor preferences'
)

Works with Claude Code, Cursor, and any MCP client

Perlith ships an MCP server. One line in your config, five tools available to your agent: init, store, retrieve, search, and list.

// claude_desktop_config.json or .claude.json
{
  "mcpServers": {
    "perlith": {
      "command": "npx",
      "args": ["perlith-mcp"],
      "env": { "PERLITH_BASE_DIR": "./memory" }
    }
  }
}

Or connect to the hosted endpoint at perlith.dev/mcp for quick experimentation.

Full audit trail

Every decision your agent makes is traceable. No opaque vector stores, no hidden state.

When was this fact learned? How has it changed?

What changed in the last memory consolidation?

Which agent authored each line of this memory?

Architecture

Perlith is modeled on human memory consolidation. Raw experiences (L1) are clustered overnight into durable facts (L2). Repeated patterns are elevated to procedures (L3). A decay function ensures retrieval quality stays high by letting stale memories fade.

There is no vector database. There is no infrastructure to manage. It runs wherever Node runs, stores data wherever files live, and versions history wherever git works.