# @kuns/claude-mailbox

Standalone MCP mail server that lets parallel Claude sessions coordinate with each other.

## Install

One-time per machine:

```sh
npm config set @kuns:registry=https://git.kuns.dev/api/packages/releases/npm/
npm install -g @kuns/claude-mailbox
```

Then:

```sh
claude-mailbox install-autostart   # registers per-OS autostart, no admin needed by default
```

See the [repository README](https://git.kuns.dev/releases/ClaudeMailbox/src/branch/main/README.md) for the full architecture, MCP tool reference, and `.mcp.json` snippet.

## Claude Code hook (auto-check inbox)

Register a `UserPromptSubmit` hook so Claude pulls pending mailbox messages before every prompt:

```sh
claude-mailbox install-hook --name alice            # patches ~/.claude/settings.json
claude-mailbox install-hook --name alice --project  # patches <cwd>/.claude/settings.json
claude-mailbox uninstall-hook                       # remove again
```

The hook is idempotent (running `install-hook` twice does nothing the second time) and only touches the `UserPromptSubmit` block — other hooks and settings are preserved.

Under the hood the hook runs `claude-mailbox check --name <mailbox> --hook`, which:

- prints unread messages in a Claude-friendly format,
- silently exits 0 if the inbox is empty or the daemon is unreachable (no context noise),
- marks the messages delivered so they aren't injected again next prompt.

Cost: one local HTTP round-trip plus Node coldstart per prompt (~100ms on Windows).

## Troubleshooting

`npm install` returns `401 Unauthorized`
:   The Gitea registry usually serves the `releases` scope publicly, but if your instance requires auth you'll need a read token:

    ```sh
    npm config set //git.kuns.dev/api/packages/releases/npm/:_authToken=<token>
    ```

`Cannot find module 'node:sqlite'` or similar
:   claude-mailbox uses Node's built-in `node:sqlite`, stable since Node 24. On Node 22.5–23.x it works only with `--experimental-sqlite`. Upgrade to Node 24 LTS or newer: `nvm install 24 && nvm use 24` (or `winget install OpenJS.NodeJS.LTS` on Windows).