chronos-mcp 0.1.15

Local-first email and calendar inbox for AI agents

Chronos — agent-inbox

Local-first email and calendar inbox for AI agents. Syncs Gmail and Google Calendar into a single queryable SQLite database and exposes all data through an MCP server.

Features

• Sync multiple Gmail and Google Calendar accounts into one SQLite database
• Full-text search via FTS5 (messages and events)
• MCP server at localhost:7071/sse for agent integration
• HTTP REST API at localhost:7070 for direct queries
• Read-only SQL interface via POST /v1/query
• Optimistic event writes with provider-wins conflict resolution
• Incremental sync with historyId (Gmail) and syncToken (Calendar)
• ULID primary keys, WAL mode, no cloud dependencies at query time

Installation

pipx install chronos-mcp

Or from source:

git clone https://github.com/CourtimusPrime/chronos.git
cd chronos
pip install -e .

Setup

Prerequisites

1. Go to console.cloud.google.com and create a project
2. Enable Gmail API and Google Calendar API
3. OAuth consent screen → External:
   • Add yourself as a Test User and keep the app in Testing mode (Production requires CASA verification for the Gmail scope)
   • Under "Add or remove scopes" → filter restricted → tick https://mail.google.com/
   • Also add https://www.googleapis.com/auth/calendar
4. Credentials → Create Credentials → OAuth client ID:
   • Application type: Web application
   • Authorized redirect URI: http://localhost:9004/callback (override via oauth.callback_port in config.yml if needed)
5. Download the credentials JSON file

Desktop App credentials ("installed" JSON shape) are not supported — Chronos uses the https://mail.google.com/ restricted scope, which is only practical on a Web Application OAuth client in Testing mode.

Register an account

Run chronos --help for full Google Cloud Console setup instructions.

# Step 1: Stage your credentials (Web Application OAuth JSON from Google Cloud Console)
chronos --use /path/to/credentials.json

# Step 2: Register an account (opens browser for OAuth2 consent)
chronos --add personal

Staged credentials persist until the next --use call, so you can register multiple accounts with one credentials file:

chronos --use /path/to/credentials.json
chronos --add personal
chronos --add work

The --add step:

• Writes ~/.chronos/personal_token.json (self-contained token file)
• Creates two rows in the accounts table (gmail + google_calendar)
• Prints a confirmation summary

Start syncing

chronos --start

The daemon starts on 127.0.0.1:7070 (HTTP) and 127.0.0.1:7071 (MCP/SSE).

CLI Reference

chronos --use CREDENTIALS_PATH          # Stage a credentials JSON for --add
chronos --add ALIAS                     # Register a new account (requires prior --use)
chronos --remove ALIAS                  # Remove an account and its data
chronos --list                          # List all registered accounts
chronos --test ALIAS                    # Test account tokens
chronos --start [--http-port N] [--mcp-port N]  # Start daemon
chronos --stop                          # Stop the running daemon (preserves synced data)
chronos --status                        # Show sync status
chronos --sync [ALIAS] [--type full|incremental]  # Trigger sync

Ctrl+C vs --stop: Pressing Ctrl+C while chronos --start is running wipes synced data (emails, threads, events, calendars) but preserves accounts. Use chronos --stop from another terminal for a clean shutdown that preserves data.

Run chronos --help for Google Cloud Console setup steps.

Environment Variables

Variable	Default	Description
CHRONOS_HOME	~/.chronos	Credentials and database directory
CHRONOS_DB_PATH	$CHRONOS_HOME/chronos.db	SQLite database file
CHRONOS_HTTP_PORT	7070	HTTP API port
CHRONOS_MCP_PORT	7071	MCP server port
CHRONOS_LOG_LEVEL	INFO	Log level

Configuration

config.yml (searched in $CHRONOS_CONFIG, ./config.yml, then ~/.chronos/config.yml) exposes additional settings. The OAuth callback is one of them:

settings:
  oauth:
    callback_port: 9004     # local server bind during `chronos --add`
    callback_path: /callback # appended to the redirect URI

If you change callback_port, update the Authorized redirect URI in your Web Application OAuth client to match.

License

MIT