Google Tasks MCP

Overview

Google Tasks MCP is a local Python MCP server that lets compatible AI agents read and manage the authenticated user's Google Tasks. It uses Google's official Tasks API, OAuth 2.0 Desktop App credentials, and the MCP Python SDK over stdio.

This repository is one component of the Google Services MCP collection.

The Git repository is named google-task-mcp (singular), while the Python distribution and console commands are named google-tasks-mcp (plural). The paths and commands below preserve those names.

The package is currently classified as Alpha in pyproject.toml.

Related MCP server: Google Tasks MCP Server

Features

• List, inspect, create, rename, and delete task lists.

• List and filter tasks with API pagination.

• Create, edit, complete, reopen, move, reorder, and delete tasks.

• Create and move subtasks using parent and previous.

• Hide completed tasks through Google Tasks' clear operation.

• Preserve the distinction between an omitted update field and explicit null used to clear notes or due.

• Publish MCP safety annotations and require explicit confirmation for destructive operations.

• Store the OAuth refresh token outside the repository with owner-only permissions.

• Run entirely on Python; Node.js is not required.

MCP tools

Google Tasks stores only the date portion of a due timestamp; the API discards a supplied time-of-day. Task titles are limited to 1,024 characters and notes to 8,192 characters.

All input objects reject unknown fields. IDs and other required strings must be non-empty. The complete input contract is:

The five list_tasks time filters must be RFC 3339 timestamps with a timezone. A due value may instead be YYYY-MM-DD; the server validates calendar dates and normalizes due values to UTC before calling Google. To see tasks completed in Google's first-party clients, set both show_completed and show_hidden to true.

For update_task, omit fields that should remain unchanged and use explicit null only to clear notes or due. Explicit null for title or status is rejected before any Google API call.

List operations return task_lists or tasks plus next_page_token. Other successful operations return Google's resource object, except deletes and clear, which return a small acknowledgement. Results are JSON in MCP text content. Validation, authentication, and Google API failures are returned as MCP tool errors. clear_completed_tasks uses Google Tasks' clear operation, which hides completed tasks; it does not permanently delete each task.

Requirements

• Python 3.11 or newer, matching requires-python = ">=3.11" in pyproject.toml. The examples below use Python 3.12 where an explicit interpreter is useful.

• uv or another Python package installer.

• A Google account.

• A Google Cloud project with the Google Tasks API enabled.

• A local MCP client that supports stdio servers.

Installation

Clone the repository and install the development environment:

git clone https://github.com/phamviet86/google-task-mcp
cd google-task-mcp
uv sync --extra dev

To build wheel and source distributions:

uv build

For an immutable deployment, install a specific Git commit into a dedicated virtual environment:

uv venv --python /usr/bin/python3.12 /opt/google-tasks-mcp/venv
uv pip install \
  --python /opt/google-tasks-mcp/venv/bin/python \
  "git+https://github.com/phamviet86/google-task-mcp@<commit>"

The installed server entry point is /opt/google-tasks-mcp/venv/bin/google-tasks-mcp.

Google Cloud and OAuth setup

1. Open Google Cloud Console.

2. Create or select a project.

3. Enable Google Tasks API under APIs & Services → Library.

4. Configure the OAuth consent screen.

5. Under APIs & Services → Credentials, create an OAuth client ID with application type Desktop app.

6. Download the OAuth Desktop client JSON as client_secret.json and keep it protected outside this repository.

Authorize from a desktop that can open the browser consent flow:

uv run google-tasks-mcp-auth \
  --client-secret /secure/google/client_secret.json

The command accepts only a Google OAuth Desktop client JSON containing the top-level installed object. It requests the full https://www.googleapis.com/auth/tasks scope because this server exposes read and write operations. The token defaults to:

~/.config/google-tasks-mcp/token.json

Later runs refresh expired credentials automatically. Refresh is guarded in-process so concurrent tool calls do not refresh the same token repeatedly; the refreshed authorized-user token is atomically persisted with owner-only permissions before the service is built. The same OAuth Desktop client definition may be used to authorize another local application, but each service should keep its own token with its exact scope. Do not reuse a broader Google Workspace token as this service's token.

Environment variables

~ is expanded in GOOGLE_TOKEN_FILE. A relative token override remains relative to the MCP subprocess's working directory, so use an absolute path in client configuration. The retry value is passed to every Google request as execute(num_retries=...); the SDK applies randomized exponential backoff. The default 3 means one initial attempt plus at most three retries. Set it to 0 to disable retries.

For example, authorize and store the token at an explicit protected path:

GOOGLE_TOKEN_FILE=/secure/google/tasks-token.json \
uv run google-tasks-mcp-auth \
  --client-secret /secure/google/client_secret.json

Pass the same GOOGLE_TOKEN_FILE value to the MCP server. Never commit the OAuth client JSON or generated token.

Running the server

From the development checkout:

uv run google-tasks-mcp

google-tasks-mcp accepts no command-line arguments. The authorization helper accepts one required argument, --client-secret PATH; use google-tasks-mcp-auth --help for its generated CLI help.

An MCP client normally launches the virtual-environment console script directly:

/absolute/path/google-task-mcp/.venv/bin/google-tasks-mcp

The server always communicates over stdio and does not open a network port.

MCP client configuration

Use absolute paths and restart the MCP client after changing its configuration.

Codex

Add the server to ~/.codex/config.toml or a trusted project .codex/config.toml:

[mcp_servers.google_tasks]
command = "/absolute/path/google-task-mcp/.venv/bin/google-tasks-mcp"

[mcp_servers.google_tasks.env]
GOOGLE_TOKEN_FILE = "/Users/you/.config/google-tasks-mcp/token.json"
GOOGLE_API_NUM_RETRIES = "3"

See the official Codex MCP guide for current client configuration details.

Hermes Agent

Hermes reads MCP servers from ~/.hermes/config.yaml:

mcp_servers:
  google_tasks:
    command: "/absolute/path/google-task-mcp/.venv/bin/google-tasks-mcp"
    args: []
    env:
      GOOGLE_TOKEN_FILE: "/Users/you/.config/google-tasks-mcp/token.json"
      GOOGLE_API_NUM_RETRIES: "3"
    timeout: 120
    connect_timeout: 30

Use the absolute token path directly in the server's env mapping. Do not enable supports_parallel_tool_calls for the complete tool set because it includes writes to shared task lists. See the official Hermes MCP guide.

Generic MCP clients

For clients that use JSON configuration, the equivalent transport settings are:

{
  "mcpServers": {
    "google_tasks": {
      "command": "/absolute/path/google-task-mcp/.venv/bin/google-tasks-mcp",
      "env": {
        "GOOGLE_TOKEN_FILE": "/secure/google/tasks-token.json",
        "GOOGLE_API_NUM_RETRIES": "3"
      }
    }
  }
}

Configuration syntax is client-specific; use the client's native MCP adapter rather than assuming that every client accepts the same JSON shape.

Usage and examples

A typical safe workflow is:

1. Call list_task_lists to resolve a human-readable list name to its ID.

2. Call list_tasks or get_task before modifying an existing task.

3. Use a write tool such as create_task, update_task, or move_task.

4. Obtain explicit user confirmation before calling delete_task_list, delete_task, or clear_completed_tasks with confirm: true.

The Python implementation preserves the previous TypeScript tool names, arguments, pagination defaults, safety annotations, date normalization, and omitted-versus-null update behavior.

There is no local task database, cache, index, background synchronization job, webhook, or network listener. Each tool call accesses Google Tasks API v1 through the official Python client. The only persistent local state managed by this package is the OAuth authorized-user token.

Each MCP tool call builds a fresh Google Tasks service and executes the complete operation in one worker thread. No googleapiclient service or httplib2 transport is shared across threads. This follows the Google client library's thread-safety guidance while still allowing independent MCP calls to run concurrently. The service is closed in that same worker thread after every call, including when request execution fails, so its underlying sockets are not retained.

Troubleshooting

• Authentication error: run google-tasks-mcp-auth again and confirm that the MCP subprocess receives the same GOOGLE_TOKEN_FILE value.

• Token path looks correct but is not found: use an absolute GOOGLE_TOKEN_FILE; relative paths are evaluated from the MCP subprocess's working directory.

• Retry configuration error: set GOOGLE_API_NUM_RETRIES to an integer from 0 through 10.

• No refresh token was returned: revoke the application's existing Google account grant, then run the authorization helper again as directed by its error message.

• Expired token has no refresh token: run the authorization helper again; the server refuses to build a service from credentials that cannot be refreshed.

• Browser flow cannot open: authorize on a desktop that can complete the installed-app OAuth flow, then protect and transfer the generated service-specific token if needed.

• Tools are missing: restart the MCP client and verify the absolute command path. A fresh MCP client should discover exactly 14 tools.

• Due time is missing: Google Tasks retains only the date portion of a due timestamp.

• Migrating from the TypeScript release: preserve the protected token, install the Python package separately, point the client at google-tasks-mcp, verify all 14 tools with live read/write/cleanup checks, and only then remove the old Node.js checkout.

Security

Report vulnerabilities privately according to the security policy. Never include credentials or real task data in a public issue.

• Keep client_secret.json and OAuth tokens outside source control and restrict their filesystem permissions.

• Use a dedicated token directory: authorization sets its directory to mode 0700 and writes the token atomically with mode 0600 on POSIX systems.

• Grant only the Google Tasks scope used by this service and keep separate tokens for other Google services.

• Treat create, update, move, clear, and delete operations as writes. Destructive tools require explicit confirmation, but the local account and MCP client still control access to the server.

• For one user on one workstation or VPS, stdio plus a protected local token is the simplest deployment. A multi-user hosted service requires per-user OAuth sessions, encrypted server-side token storage, and an appropriate network transport; never share one refresh token among users.

Development and contributing

Read CONTRIBUTING.md before opening a pull request. Participation is governed by the Contributor Covenant Code of Conduct.

Run all configured checks before submitting a change:

uv run ruff format --check .
uv run ruff check .
uv run mypy
uv run pytest

The regression suite dispatches all 14 tools against a fake Google Tasks client, verifies destructive confirmation, and tests omitted-versus-null update behavior.

For non-security bugs and feature requests, use the repository's structured issue templates.

License

MIT

References

• Google Tasks API REST reference

• Google Tasks resource fields

• Google Tasks ordering

• Google OAuth 2.0

• MCP Python SDK

• Google API Python client thread safety

• Google API Python client request execution and retries