Meridian

Claude Code has no memory between sessions. Meridian fixes that.

Open-source MCP server for persistent AI session memory — shared task log, pinned decisions, human-in-the-loop queue, and tiered handoffs. Works with Claude Code, Cursor, Cline, Claude Desktop, or any MCP client.

Why Meridian

Every AI coding session boots blind. You re-explain the architecture, re-describe the constraints, re-list what's been tried. When context fills up mid-task, everything is lost. This is context debt — and it compounds.

Meridian gives your sessions shared memory. They see the same task log, the same pinned decisions, the same goal state. When context fills up, a new session resumes from a compressed handoff in seconds. No copy-paste, no re-explaining from scratch.

Related MCP server: Mnehmos Synch

What it is, in 30 seconds

A local MCP server every AI session connects to. They share goal state, see each other's task log, and resume from a compressed handoff when context fills up.

Two ways to run Meridian:

• Self-host — free forever, any team size. Clone and run in 2 commands.

• Hosted at usemeridian.us — 30 days free (no card), then $20/mo Standard.

Quickstart — from source

Linux / macOS:

git clone https://github.com/meridianmcp/Meridian
cd Meridian
./install.sh
pixi run start

Windows (PowerShell):

git clone https://github.com/meridianmcp/Meridian
cd Meridian
.\install.ps1
pixi run start

Dashboard opens at http://localhost:7878. Data persists in ./data/meridian.db.

Wire it into your AI client

Claude Code

Drop a .mcp.json at your project root.

Hosted (no install) — generate an API key at usemeridian.us/settings:

{
  "mcpServers": {
    "meridian": {
      "type": "http",
      "url": "https://usemeridian.us/mcp",
      "headers": { "Authorization": "Bearer sk_meridian_YOUR_KEY_HERE" }
    }
  }
}

Self-host (from source):

{
  "mcpServers": {
    "meridian": {
      "command": "pixi",
      "args": ["run", "python", "-m", "meridian", "--mcp"],
      "cwd": "/absolute/path/to/Meridian"
    }
  }
}

Cursor / Windsurf

Same JSON snippet — both clients read .mcp.json from the project root.

Claude Desktop

Add the same mcpServers block to:

• Windows: %APPDATA%\Claude\claude_desktop_config.json

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

Restart Claude Desktop. New chats have Meridian tools.

claude.ai web (recommended for planning chat)

Use dnakov/claude-mcp — included as a submodule — to bridge claude.ai to your local Meridian server:

git clone --recurse-submodules https://github.com/meridianmcp/Meridian

1. Open chrome://extensions and enable Developer mode

2. Click Load unpacked and select extensions/claude-mcp

3. Click the extension icon and set the URL to http://localhost:7878/mcp

All 54+ Meridian tools (checkpoint, log_task, pin_decision, etc.) are now available directly in claude.ai planning chat. No copy-pasting session output.

Hosted tier (no install)

Sign in at usemeridian.us → Settings → MCP client setup → Generate API key → Copy config.

Or manually:

{"mcpServers":{"meridian":{"type":"http","url":"https://usemeridian.us/mcp","headers":{"Authorization":"Bearer sk_meridian_YOUR_KEY_HERE"}}}}

claude.ai (browser) users: install the dnakov/claude-mcp Chrome extension, then visit usemeridian.us/install-mcp for a step-by-step setup guide with one-click copy buttons.

Get your API key at usemeridian.us/settings after sign-in. Free tier: 30 days, no card, full features.

What you get

• Dashboard at http://localhost:7878 — sessions, tasks, sprint board, swimlane timeline, HITL queue, pinned decisions.

• MCP tools — start_session, log_task, claim_task, set_decision, pin_decision, request_hitl, generate_handoff, and ~50 more.

• Symbol-level parallel safety — claim_file can claim a single class or function (parsed with ast / tree-sitter) so two sessions edit the same file safely; an overlapping claim is blocked with the free symbols listed.

• Live work queue — planners inject sprint items mid-run; executors pick them up at the next item boundary via a board_change signal, no interruption.

• HITL recommended option — request_hitl can flag a safe-default option the dashboard highlights; Enter submits it, number keys pick others.

• GitHub hub (hosted) — connect your repo once in Settings; sessions get read_file, list_files, search_code, git_log, get_commit injected automatically. No extra install.

• Tiered handoffs — L0/L1/L2 compression so a fresh session can resume in seconds.

• Webhook intake — push events from LangGraph / Autogen / custom agents into the same dashboard.

• Works everywhere — Claude Code, Claude Desktop, Cursor, Windsurf, LangGraph, custom.

How it works

> start_session(project_id="meridian", session_name="feature-x")
  ✓ session registered · sprint loaded · 12 active tasks

> get_tasks(project_id="meridian", limit=5)
  [DONE]    backend / wire decisions_pinned table
  [PENDING] frontend / add notes vtab (claimed by session-2)

> claim_task(task_id="a1f3...")
  ✓ claimed — other sessions skip this one

State lives in data/meridian.db (SQLite) or a Postgres URL via MERIDIAN_DB_URL. No cloud required for local use.

Team coordination

Point MERIDIAN_DB_URL at a shared Postgres (Neon free tier works great). Every teammate runs their own local Meridian against the same DB — instant shared sessions, no Meridian server in the cloud.

Auto-checkpoint with hooks

One command wires Claude Code and Codex to Meridian. Every session start injects your project context automatically. Every session end snapshots completed work and writes a delta handoff.

Mac/Linux:

curl -fsSL https://usemeridian.us/hooks.sh | bash

Windows:

irm https://usemeridian.us/hooks.ps1 | iex

Prompts for your Meridian server URL (default http://localhost:7878), then opens your browser to connect this machine — no project ID or API token to paste. Writes to ~/.claude/settings.json (Claude Code) or ~/.codex/config.toml (Codex). After setup, every session automatically:

1. On start — calls POST /hooks/session-start → injects goal, sprint items, recent tasks, and pinned decisions into the session context via additionalContext.

2. On stop — calls POST /hooks/stop → runs auto_capture and writes a delta handoff so the next session resumes from where this one ended.

No more manual start_session() calls. No lost work when context fills.

Hosted tier

30-day free trial · no card required

License

MSL-1.0 — free for local and internal use at any team size. Paid license required if you host Meridian as a service for others. Converts to MIT after 6 years.

For licensing questions: hello@usemeridian.us

Contributors

Built by @ajc3xc