Claude Code

Add persistent memory to Claude Code and Claude Cowork with the Mem0 plugin — MCP server, lifecycle hooks, and SDK skill.

Add persistent memory to Claude Code (CLI) and Claude Cowork (desktop app) with the Mem0 plugin. Your agent forgets everything between sessions — this plugin fixes that by connecting to Mem0’s cloud memory layer via MCP, automatically capturing learnings at key lifecycle points, and retrieving relevant context before every response.

Prerequisites

Before setting up Mem0 with Claude Code, ensure you have:

1. A Mem0 Platform account and API key:

   • Sign up at app.mem0.ai
   • Get your API key (starts with m0-)

2. Claude Code CLI or Claude Cowork desktop app installed

3. Your API key added to your shell profile (persists across sessions):

zsh

echo 'export MEM0_API_KEY="m0-your-api-key"' >> ~/.zshrc
source ~/.zshrc

Confirm it’s set:

echo $MEM0_API_KEY
# Should print: m0-your-api-key

Installation

Option A — Plugin Marketplace (Recommended)

Install the full plugin including MCP server, lifecycle hooks, and SDK skill.

1. Add the Mem0 marketplace:

   /plugin marketplace add mem0ai/mem0
   

2. Install the plugin:

   /plugin install mem0@mem0-plugins
   

Claude Cowork desktop app: Open the Cowork tab, click Customize in the sidebar, click Browse plugins, and install Mem0.

Option B — MCP Only

Add the Mem0 MCP server directly with a single command:

npx mcp-add \
  --name mem0-mcp \
  --type http \
  --url "https://mcp.mem0.ai/mcp" \
  --clients "claude code"

This gives you the MCP tools but not the lifecycle hooks or SDK skill.

Option C — Manual MCP Configuration

Add to your Claude Code MCP config (.mcp.json):

{
  "mcpServers": {
    "mem0": {
      "type": "http",
      "url": "https://mcp.mem0.ai/mcp/",
      "headers": {
        "Authorization": "Token ${MEM0_API_KEY}"
      }
    }
  }
}

Start a new session and ask: “List my mem0 entities” or “Search my memories for hello”. If the mem0 tools appear and respond, you’re all set.

Post-Installation: Run /mem0:onboard

After installing the plugin, start a new Claude Code session and run:

/mem0:onboard

This runs the setup wizard which:

1. Verifies your API key and MCP connection
2. Detects and imports project files (CLAUDE.md, AGENTS.md, .cursorrules)
3. Installs coding-optimized memory categories
4. Shows your identity (user ID, project scope, branch)

The onboarding is idempotent — safe to re-run anytime. It auto-triggers on first session in a new project, but you can always invoke it manually.

What’s Included

Component	Plugin Install	MCP Only
MCP Server (9 memory tools)	Yes	Yes
Lifecycle Hooks	Yes	No
Mem0 SDK Skill	Yes	No

Available MCP Tools

Once installed, the following tools are available in every Claude Code session:

Tool	Description
add_memory	Save text or conversation history for a user/agent
search_memories	Semantic search across memories with filters
get_memories	List memories with filters and pagination
get_memory	Retrieve a specific memory by ID
update_memory	Overwrite a memory’s text by ID
delete_memory	Delete a single memory by ID
delete_all_memories	Bulk delete all memories in scope
delete_entities	Delete a user/agent/app/run entity and its memories
list_entities	List users/agents/apps/runs stored in Mem0

Lifecycle Hooks

When installed via the plugin marketplace, Mem0 hooks into Claude Code’s lifecycle to automatically manage memory:

Hook	Event	What it does
Session start	SessionStart	Loads prior memories and displays status banner
User prompt	UserPromptSubmit	Searches relevant memories before each message; skips short prompts
Pre-tool	PreToolUse	Blocks MEMORY.md writes, enforces user_id/app_id on mem0 tool calls
Post-tool	PostToolUse	Tracks stats, scans bash errors for related memories
Pre-compact	PreCompact	Stores a session summary before context compaction

Example Workflow

# Session 1: Working on a feature
You: Let's refactor the auth module to use JWT tokens instead of sessions.

# Claude searches memories, finds nothing relevant, proceeds with the work.
# After completing the task, Mem0 stores:
#   - Decision: "Migrated auth from sessions to JWT tokens"
#   - Files modified: auth/middleware.ts, auth/token.ts
#   - User preference: "Prefers TypeScript, uses ESLint"

# Session 2 (days later): Related work
You: Add refresh token rotation to the auth system.

# Claude searches memories, retrieves the JWT migration context.
# Knows the file structure, decisions made, and user preferences.
# Continues seamlessly without re-explaining the codebase.

Troubleshooting

• “Connection failed” — Verify MEM0_API_KEY is set in your shell: echo $MEM0_API_KEY. If empty, add it to your shell profile (see Prerequisites)
• No tools appearing — Restart your Claude Code session after installation
• Memories not being captured — Ensure you installed via the plugin marketplace (Option A) for lifecycle hooks. MCP-only installs require manual memory operations
• “Mem0 Inactive” banner every session — Your API key isn’t persisting. Add export MEM0_API_KEY="m0-..." to your ~/.zshrc (or ~/.bashrc) and run source ~/.zshrc

Mem0 MCP Setup

Detailed MCP configuration for all clients

Codex Integration

Add Mem0 memory to OpenAI Codex workflows