Add Walrus Memory to Antigravity so the agent recalls context and saves durable facts. Install it as a **plugin** (adds automatic-memory hooks) or as **MCP-only** (just the tools).

- [x] Node.js 20+
- [x] A Walrus Memory account. The first memory tool call opens a browser sign-in (`memwal_login`).

## Installation

Deploy the plugin (MCP server + lifecycle hooks) into Antigravity's plugin directory:
    ```bash
    npx degit MystenLabs/MemWal/packages/mcp/plugin ~/.gemini/config/plugins/memwal
    ```
    Restart Antigravity, then ask the agent to run `memwal_login` on first use.

## What the plugin includes

| Component | Plugin | MCP-only |
|---|:-:|:-:|
| Walrus Memory MCP (memory tools) | ✓ | ✓ |
| Lifecycle hooks (automatic recall/save) | ✓ | ✗ |

## Lifecycle hooks (plugin only)

| Hook | Event | What it does |
|------|-------|--------------|
| Session start | `SessionStart` | Announces that memory is active and reminds the agent to use the `memwal_*` tools. |
| User prompt | `UserPromptSubmit` | Injects a decision rubric so the agent chooses recall vs save from meaning (any language or spelling). |
| Post-tool | `PostToolUse` (Bash) | When a command errors, reminds the agent to recall prior fixes and save the resolution. |

## Available tools

| Tool | Description |
|------|-------------|
| `memwal_remember` | Save a durable fact (preference, decision, constraint, identity). |
| `memwal_remember_bulk` | Save several distinct facts in one call. |
| `memwal_recall` | Semantic search across stored memories for relevant context. |
| `memwal_analyze` | Extract and save multiple facts from a passage of text. |
| `memwal_restore` | Rebuild the search index from Walrus (recovery). |
| `memwal_health` | Fast connectivity check. |
| `memwal_login` / `memwal_logout` | Connect or disconnect this client. |

The tool descriptions tell the agent to save and recall proactively. See [Reference](/walrus-memory/mcp/reference) for full parameters.

## Verify

Ask the agent what MCP tools it has available. You should see the `memwal_*` tools. State a durable fact and confirm the agent saves it with `memwal_remember`.

## Troubleshooting

- **Tools missing**: restart Antigravity after installation.
- **Not signed in**: ask the agent to run `memwal_login`, approve in the browser, then retry.
- **`memwal_recall` returns nothing although you saved before**: run `memwal_restore <namespace>` to rebuild the index from Walrus.