## Documentation Index

Fetch the complete documentation index at: [/llms.txt](https://docs.mem0.ai/llms.txt)

Use this file to discover all available pages before exploring further.

Add persistent memory to [**Google Antigravity**](https://antigravity.google/) (`agy` CLI and Desktop IDE) with the Mem0 plugin. Your agent forgets everything between sessions. Mem0 fixes that by storing decisions, preferences, and learnings so they carry over automatically.

## Prerequisites

1. A Mem0 API key (starts with `m0-`):   - [Get your API key](https://app.mem0.ai/dashboard/api-keys?utm_source=oss&utm_medium=integration-antigravity) (free sign-up at [app.mem0.ai](https://app.mem0.ai/?utm_source=oss&utm_medium=integration-antigravity))
2. Add it to your shell profile so it persists across sessions:

**zsh**
   
   ```
echo 'export MEM0_API_KEY="m0-your-api-key"' >> ~/.zshrc && source ~/.zshrc
```  
   
   **bash**
   
   ```
echo 'export MEM0_API_KEY="m0-your-api-key"' >> ~/.bashrc && source ~/.bashrc
```

## Installation

**Option A: degit** (recommended):

```bash
# Install the plugin (MCP server, hooks, scripts)
npx degit mem0ai/mem0/integrations/mem0-plugin ~/.gemini/config/plugins/mem0
```

This installs the MCP server, lifecycle hooks, and shared scripts.

## What’s Included

| Component | Included |
| --- | --- |
| MCP Server (9 memory tools) | Yes |
| Lifecycle Hooks | Yes |
| 16 Slash Commands | Yes |

## Available MCP Tools

| 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

The plugin uses the same shell scripts as Claude Code, Cursor, and Codex: hooks bridge environment variables using `${extensionPath}` (Antigravity’s plugin-root token).

| Hook | Event | What it does |
| --- | --- | --- |
| **Session start** | `SessionStart` | Loads prior memories and displays status banner |
| **User prompt** | `UserPromptSubmit` | Searches relevant memories before each message |
| **Pre-tool** | `PreToolUse` | Blocks MEMORY.md writes, enforces `user_id`/`app_id` on mem0 tools |
| **Post-tool** | `PostToolUse` | Tracks stats, scans bash errors for related memories |
| **Stop** | `Stop` | Stores a session summary at the end of every assistant turn (not just at session end) |

What you type is stored as yours. What the agent produces — session summaries and compaction summaries — is stored as the assistant’s, so its suggestions never become your stated preferences.

## Troubleshooting

- **No tools appearing**: Restart your Antigravity session after installation
- **“Connection failed”**: Verify your key is set: `echo $MEM0_API_KEY`
- **MCP 401 Unauthorized**: If `${MEM0_API_KEY}` interpolation doesn’t work in your `agy` version, replace with your literal key in `mcp_config.json`