zulipmcp

Run AI agents in Zulip as @mentionable bots — or wire into any MCP client. Also works as a Python library.

Quickstart

1. Install the package:

   bash

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   uv add zulipmcp --git https://github.com/windborne/zulipmcp.git
   

2. Add a .zuliprc file to your project root with your Zulip bot credentials. See Add a bot or integration for instructions on making a bot. The bot type must be "generic."

3. Add the MCP server to your .mcp.json:

   config.json

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   {
     "mcpServers": {
       "zulip": {
         "command": "uv",
         "args": ["run", "python", "-m", "zulipmcp.mcp"]
       }
     }
   }
   

4. Restart your MCP client. The Zulip tools should now be available.

Requirements

• Python >=3.10, managed with uv
• A .zuliprc file for Zulip API auth (see Quickstart)
• For listener mode: the selected backend CLI installed and authenticated (claude by default, codex with --backend codex, or opencode with --backend opencode)

Entry Points

Library Usage

zulipmcp can also be imported directly as a Python library:

import zulipmcp

# Fetch and format recent messages
messages = zulipmcp.get_messages(hours_back=24, channels=["engineering"])
print(zulipmcp.format_messages(messages))

# Send a message
zulipmcp.send_message("engineering", "general", "Hello from Python!")

# Configure MCP hooks before starting the server
zulipmcp.configure(
    message_prefix=lambda: "[bot] ",
    on_session_end=lambda session: print(f"Session ended in #{session.stream}"),
)

Hermes Gateway

Hermes uses the native hermes_plugin/zulip gateway adapter instead of the subprocess listener. Each stream/topic maps to its own persistent Hermes session, while zulipmcp remains available as the explicit Zulip API tool layer.

• Mention the bot once to activate a topic; follow-ups do not need a mention.
• Each user message is a fresh Hermes turn with a fresh iteration budget.
• Typing, normal response delivery, status reactions, approval reactions, and :stop_sign: interruption are handled by the adapter.
• Only same-topic history is added on first activation.
• After a gateway restart, mention once to reactivate the topic; Hermes resumes the same stored session.

See the plugin README for installation, configuration, access controls, and verification.

Direct launch (no listener)

An existing coordinator can start one Claude Code or Codex session directly. The coding agent uses its configured zulip MCP server to initialize the target topic, reply there, and wait for follow-ups:

python -m zulipmcp.launch_agent \
  --backend claude \
  --agent-command /path/to/claude \
  --stream engineering \
  --topic "large coding task" \
  --working-dir /path/to/project

python -m zulipmcp.launch_agent \
  --backend codex \
  --agent-command /path/to/codex \
  --stream engineering \
  --topic "large coding task" \
  --working-dir /path/to/project

The launcher does not watch Zulip or spawn on mentions. It starts exactly one foreground coding-agent process and reuses the bundled session instructions. Run it as a background process when the coordinator should continue working. By default the agent listens in renewable two-hour intervals and does not exit merely because an interval timed out. Use --trigger-message-id and --session-user-email when that metadata is available. Pass --zuliprc or --mcp-config only when the agent should not use its existing global MCP configuration. An explicit Claude MCP config is loaded strictly so a project-local server with the same name cannot shadow it.

Listener

The optional zulipmcp.listener module watches Zulip for @mentions and spawns one headless agent session per (stream, topic). It supports Claude Code by default, Codex with --backend codex, and OpenCode with --backend opencode. It's the glue between Zulip events and the agent backend -- the MCP server handles all the Zulip tools, the listener just handles lifecycle.

# Minimal -- uses ./.zuliprc, ./.mcp.json (if present), and the bundled default prompt
uv run python -m zulipmcp.listener

# Full -- override MCP config and system prompt
uv run python -m zulipmcp.listener \
    --mcp-config .mcp.json \
    --system-prompt agent.md \
    --log-dir ./logs

# Recommended: Claude Code with Opus 4.6
uv run python -m zulipmcp.listener -- --model claude-opus-4-6

# Recommended: Codex with GPT-5.5 and medium reasoning
uv run python -m zulipmcp.listener --backend codex -- \
    --model gpt-5.5 \
    -c 'model_reasoning_effort="medium"'

# Recommended: OpenCode with any provider (Qwen, Llama, Gemini, etc.)
uv run python -m zulipmcp.listener --backend opencode \
    --opencode-model anthropic/claude-sonnet-4-5

uv run python -m zulipmcp.listener --backend opencode \
    --opencode-model ollama/qwen3:235b

# Pass additional backend-specific flags after --
uv run python -m zulipmcp.listener -- --strict-mcp-config --effort medium
uv run python -m zulipmcp.listener --backend codex -- -c 'model_verbosity="low"'
uv run python -m zulipmcp.listener --backend opencode -- --verbose

Flags:

Each session gets TRIGGER_MESSAGE_ID and SESSION_USER_EMAIL set automatically so set_context() anchors to the @mention and hooks can identify the requester.

The listener intentionally does not set model or reasoning defaults. Backend CLIs and model aliases move over time, so use the backend's user config or pass flags after --. For reproducible production behavior, pin exact backend model IDs in your deployment config instead of relying on aliases.

Custom --system-prompt files are backend instructions, not the initial task. The listener still sends a short per-session bootstrap prompt with the target stream/topic and the Zulip lifecycle contract: initialize context, send visible text through reply(), then call listen() when yielding for follow-ups.

Codex sessions launch with web search enabled to match Claude Code's default web-fetch capability. For Codex, the .mcp.json adapter whitelists inherited environment variable names for translated stdio MCP servers, mirroring Claude-style subprocess inheritance without putting env values in argv. It also forwards Zulip's direct auto-init SESSION_STREAM/SESSION_TOPIC pair when present and sets tool_timeout_sec to at least 3 hours so the long-running listen() tool can wait for follow-ups. The adapter is intentionally conservative: Claude SSE config is rejected, only command and streamable HTTP url servers are translated, and environment placeholders are supported only in env/header values that can stay out of process argv.

OpenCode sessions receive the full config via OPENCODE_CONFIG_CONTENT (inline JSON). The .mcp.json adapter translates command-based servers to OpenCode's local type (merging command+args into a single array) and url-based servers to remote type, renaming env to environment. Each translated server gets a 3-hour MCP timeout so listen() can block for follow-ups; listen() sends MCP progress notifications during its long-poll loop, which OpenCode uses to reset its per-call timeout. The system prompt file path is passed via the instructions config field.