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ClaudeMailbox/node
Mika Kuns ee0b72f43b
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feat: change default port from 47822 to 37849 (v1.2.0)
47822 collided with ClaudeDo.Worker.exe on at least one user's machine.
37849 is high, registered to nobody, and avoids the prior conflict.
Both the Node port and the .NET port move together (still
wire-compatible). Defaults change only — if a user has a custom port
in mailbox.json, that stays.
2026-05-19 14:07:56 +02:00
..

@kuns/claude-mailbox

Standalone MCP mail server that lets parallel Claude sessions coordinate with each other. TypeScript / Node port of the .NET claude-mailbox daemon — wire-compatible (same port, same X-Mailbox header, same MCP tool names, same SQLite schema).

Install

One-time per machine:

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

Then:

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

See the repository README 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:

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:
npm config set //git.kuns.dev/api/packages/releases/npm/:_authToken=<token>
gyp ERR! find VS on Windows during install
better-sqlite3 ships prebuilt binaries for current Node LTS versions. If yours isn't covered, npm falls back to building from source and needs the Visual Studio Build Tools. Either install them or pin to a Node version with a matching prebuild.