Background AI Chat Server

MCP server that drives chat.sakana.ai via headless Chrome — persistent sessions for AI assistant use.

Installation

Via npx (recommended — no install needed)

npx background-ai-chat

Via npm global install

npm install -g background-ai-chat
background-ai-chat

From source (for development)

git clone https://github.com/misternay/mcp-sakana-chat.git
cd mcp-sakana-chat
npm install && npm run build && npm start

Claude Desktop Config

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or equivalent:

{
  "mcpServers": {
    "sakana-chat": {
      "command": "npx",
      "args": ["-y", "background-ai-chat"]
    }
  }
}

Why -y flag: Skips npm's install confirmation prompt, required for non-interactive usage.

Alternative (if globally installed):

{
  "mcpServers": {
    "sakana-chat": {
      "command": "background-ai-chat"
    }
  }
}

Environment Variables

Variable	Default	Description
BAC_TRANSPORT	stdio	stdio or http-sse
BAC_AUTH_KEY	""	Bearer token for HTTP/SSE
BAC_PORT	3456	HTTP/SSE port
BAC_BROWSER_HEADLESS	true	Run Chrome headless
BAC_MAX_SESSIONS	5	Max concurrent sessions
BAC_DATA_DIR	~/.background-ai-chat	Root data directory

MCP Tools

• session_open — Open a persistent chat session. Input: { login?, headless?, tosAccepted? } → Output: { sessionId, conversationId, mode, rateLimit, tosSummary }
• chat_send — Send a message with streaming token events. Input: { sessionId, message } → Output: { reply, tokens[] }
• chat_interrupt — Abort an in-flight message. Input: { sessionId } → Output: { interrupted: true }
• session_close — Close a session and release its browser. Input: { sessionId, keepHistory? } → Output: { closed, messagesExchanged }
• session_list — List all known sessions. Input: {} → Output: { sessions[] }

First call requires tosAccepted: true. Subsequent calls reuse the machine-wide ack.

Guardrails

• ToS gate — machine-wide acknowledgment of Sakana Terms 5.8/5.9
• Cookie isolation — separate browser context per session
• No message logging — only metadata (sessionId, event, ms) to stderr
• Personal/internal use only — not a competing product

Development

npm run build       # compile TypeScript
npm test            # run tests
npm run test:watch  # watch mode