MCP Graylog

MCP Graylog is a Model Context Protocol server for querying Graylog 6+ from AI assistants. The default transport is Codex stdio. Streamable HTTP is available only when you explicitly opt in for a remote, shared, or containerized runtime. The server uses MCP Python SDK 2.x and supports its current and legacy protocol revisions.

Install Dependencies

Use Python 3.11 or newer. If you are new to Python projects, the safest setup is to keep this server in its own virtual environment.

1. Install Python 3.11+ and uv.

   On macOS with Homebrew:

   brew install python@3.11 uv
   

   If Python is already installed, you can install uv with pip:

   python3 -m pip install --user uv
   

2. Create and activate a virtual environment from the repository root:

   uv venv venv --python 3.11
   source venv/bin/activate
   

3. Install the server dependencies:

   uv pip install -e .
   

   For development, tests, linting, and type checks, install the dev extras:

   uv pip install -e ".[dev]"
   

4. Check that the command is available:

   uv run mcp-graylog --help
   

5. If you installed the dev extras, run the test suite:

   uv run pytest -q
   

Quick Start: Codex Stdio

Install the project dependencies, then add this server to your Codex config:

[mcp_servers.graylog]
command = "uv"
args = ["run", "mcp-graylog"]

[mcp_servers.graylog.env]
GRAYLOG_ENDPOINT = "https://graylog.example.com"
GRAYLOG_TOKEN = "gl2-your-token"
MCP_SERVER_TRANSPORT = "stdio"

Run the command from this repository when Codex starts the MCP server:

uv run mcp-graylog

Token authentication with GRAYLOG_TOKEN is preferred. Legacy basic credentials are still supported by the runtime for older installations, but new setups should use a Graylog access token.

MCP Client Configuration Examples

All local client examples use stdio. Run them from this repository checkout, or replace uv with an absolute command that can start mcp-graylog in your environment.

Codex

Add this to ~/.codex/config.toml:

[mcp_servers.graylog]
command = "uv"
args = ["run", "mcp-graylog"]

[mcp_servers.graylog.env]
GRAYLOG_ENDPOINT = "https://graylog.example.com"
GRAYLOG_TOKEN = "gl2-your-token"
MCP_SERVER_TRANSPORT = "stdio"

Claude Code

For a project-shared server, add .mcp.json at the repository root:

{
  "mcpServers": {
    "graylog": {
      "type": "stdio",
      "command": "uv",
      "args": ["run", "mcp-graylog"],
      "env": {
        "GRAYLOG_ENDPOINT": "https://graylog.example.com",
        "GRAYLOG_TOKEN": "gl2-your-token",
        "MCP_SERVER_TRANSPORT": "stdio"
      }
    }
  }
}

Equivalent CLI setup:

claude mcp add-json graylog '{"type":"stdio","command":"uv","args":["run","mcp-graylog"],"env":{"GRAYLOG_ENDPOINT":"https://graylog.example.com","GRAYLOG_TOKEN":"gl2-your-token","MCP_SERVER_TRANSPORT":"stdio"}}'

Cursor

Add .cursor/mcp.json in the project, or ~/.cursor/mcp.json globally:

{
  "mcpServers": {
    "graylog": {
      "type": "stdio",
      "command": "uv",
      "args": ["run", "mcp-graylog"],
      "env": {
        "GRAYLOG_ENDPOINT": "https://graylog.example.com",
        "GRAYLOG_TOKEN": "gl2-your-token",
        "MCP_SERVER_TRANSPORT": "stdio"
      }
    }
  }
}

OpenCode

Add this to opencode.jsonc:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "graylog": {
      "type": "local",
      "command": ["uv", "run", "mcp-graylog"],
      "environment": {
        "GRAYLOG_ENDPOINT": "https://graylog.example.com",
        "GRAYLOG_TOKEN": "gl2-your-token",
        "MCP_SERVER_TRANSPORT": "stdio"
      },
      "enabled": true
    }
  }
}

Hermes

Add this to ~/.hermes/config.yaml:

mcp_servers:
  graylog:
    command: "uv"
    args: ["run", "mcp-graylog"]
    env:
      GRAYLOG_ENDPOINT: "https://graylog.example.com"
      GRAYLOG_TOKEN: "gl2-your-token"
      MCP_SERVER_TRANSPORT: "stdio"

Run /reload-mcp in Hermes after changing the file.

OpenClaw

Add this to ~/.openclaw/openclaw.json under mcp.servers, or use openclaw mcp set graylog '<json>' with the same server object:

{
  "mcp": {
    "servers": {
      "graylog": {
        "command": "uv",
        "args": ["run", "mcp-graylog"],
        "env": {
          "GRAYLOG_ENDPOINT": "https://graylog.example.com",
          "GRAYLOG_TOKEN": "gl2-your-token",
          "MCP_SERVER_TRANSPORT": "stdio"
        }
      }
    }
  }
}

Streamable HTTP

Use Streamable HTTP only when the server must be reachable from another process or host:

GRAYLOG_ENDPOINT="https://graylog.example.com" \
GRAYLOG_TOKEN="gl2-your-token" \
MCP_SERVER_ALLOWED_HOSTS="mcp.example.com,mcp.example.com:*" \
uv run mcp-graylog --transport streamable-http --host 0.0.0.0 --port 8000 --path /mcp

The equivalent environment setting is:

MCP_SERVER_TRANSPORT=streamable-http
MCP_SERVER_HOST=0.0.0.0
MCP_SERVER_PORT=8000
MCP_SERVER_PATH=/mcp
MCP_SERVER_DNS_REBINDING_PROTECTION=true
MCP_SERVER_ALLOWED_HOSTS=mcp.example.com,mcp.example.com:*
MCP_SERVER_ALLOWED_ORIGINS=https://app.example.com

MCP_SERVER_ALLOWED_HOSTS contains the exact hostnames accepted by the HTTP transport. Add both the bare hostname and hostname:* when clients may use an explicit port. For a direct IP deployment, use a value such as 192.0.2.10:*. Configure MCP_SERVER_ALLOWED_ORIGINS only for browser clients. To accept requests for any host behind a trusted reverse proxy, set MCP_SERVER_DNS_REBINDING_PROTECTION=false. This disables both Host and Origin validation and should not be used when the server is exposed directly.

Configuration

Graylog 6+ API Compatibility

The server uses the current Graylog Search Scripting and system APIs:

• POST /api/search/messages
• POST /api/search/aggregate
• GET /api/streams
• GET /api/streams/{stream_id}
• GET /api/system

It does not use the legacy universal search API. Search payloads use query, timerange, streams, fields, size, and from.

MCP Tools

• search_logs(search) searches messages with a typed MessageSearchInput.
• search_stream_logs(stream_id, search) searches messages in one stream.
• aggregate_logs(aggregation) runs grouped aggregations with AggregateLogsInput.
• list_streams() returns available Graylog streams.
• get_stream_info(stream_id) returns one stream definition.
• search_streams_by_name(stream_name) filters streams locally by title.
• get_system_info() returns Graylog system information.
• get_error_logs(hours=1, limit=100) searches recent error and critical logs.
• get_log_count_by_level(hours=1) aggregates recent logs by level.

Tool Input Examples

{
  "query": "level:ERROR",
  "timerange": {"value": 1, "unit": "h"},
  "streams": [],
  "fields": ["timestamp", "source", "level", "message"],
  "limit": 50,
  "offset": 0
}

{
  "query": "*",
  "timerange": {"keyword": "Last 24 hours"},
  "field": "source",
  "metric": "count",
  "limit": 10
}

{
  "stream_id": "000000000000000000000001",
  "search": {
    "query": "source:api",
    "timerange": {"value": 24, "unit": "h"},
    "fields": ["timestamp", "source", "message"],
    "limit": 25,
    "offset": 0
  }
}

Development

uv sync --extra dev
uv run pytest
uv run ruff check .

The package entrypoint is mcp-graylog, provided by mcp_graylog.cli:main.