Harvest MCP Server

A Model Context Protocol (MCP) server that integrates with the Harvest time tracking API. This server enables AI assistants like Claude to interact with your Harvest account to check projects, tasks, and log time entries.

Features

• Verify credentials and retrieve authenticated user information
• List active projects with their associated tasks
• Retrieve time entries for any date or date range with optional project/user filtering
• Log time entries for specific projects and tasks
• Start/stop/restart timers to track time in real-time
• Delete time entries when needed
• Flexible authentication: Supports both environment variables and per-call credentials

Prerequisites

• Node.js (v16 or higher recommended)
• A Harvest account with API access
• Harvest Personal Access Token and Account ID

Getting Harvest Credentials

1. Log in to your Harvest account
2. Go to Settings → Developers
3. Create a new Personal Access Token
4. Note your Account ID (visible in the URL or the token creation page)

Installation

1. Clone this repository:

git clone <repository-url>
cd harvest-mcp

1. Install dependencies:

npm install

1. Build the TypeScript code:

npm run build

Configuration

Option 1: Environment Variables (Recommended for MCP)

Configure the server in your MCP client (e.g., Claude Desktop):

Claude Desktop (~/.claude.json or %APPDATA%/Claude/config.json on Windows):

{
  "mcpServers": {
    "harvest": {
      "command": "node",
      "args": ["/absolute/path/to/harvest-mcp/build/index.js"],
      "env": {
        "HARVEST_ACCESS_TOKEN": "your-token-here",
        "HARVEST_ACCOUNT_ID": "your-account-id"
      }
    }
  }
}

Important:

• Use the absolute path to build/index.js
• Restart Claude Desktop after modifying the config
• Rebuild the project (npm run build) after any code changes

Option 2: Per-Call Credentials (Stateless Mode)

If you prefer not to use environment variables, you can pass credentials with each tool invocation:

{
  "access_token": "your-token-here",
  "account_id": "your-account-id"
}

Available Tools

get_my_profile

Verify credentials and retrieve information about the authenticated user.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID

Example Response: `` Authenticated as: John Doe ``

get_time_entries

Retrieve time entries for a specific date or date range. Supports filtering by project and user.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID
• from (optional): Start date in YYYY-MM-DD format (defaults to today)
• to (optional): End date in YYYY-MM-DD format (defaults to the from date)
• project_id (optional): Filter entries for a specific project
• user_id (optional): Filter entries for a specific user (defaults to current user)

Example Usage:

Get today's entries: ``json {} ``

Get entries for a specific date: ``json { "from": "2026-02-01" } ``

Get entries for a date range: ``json { "from": "2026-02-01", "to": "2026-02-05" } ``

Get this week's entries for a specific project: ``json { "from": "2026-02-03", "to": "2026-02-07", "project_id": 67890 } ``

Example Response: ``` Found 3 time entries for 2026-02-04:

Total hours: 6.50

[ { "id": 123456789, "spent_date": "2026-02-04", "hours": 2.5, "notes": "Implemented user authentication", "project": { "id": 67890, "name": "My Project" }, "task": { "id": 222, "name": "Development" } }, ... ] ```

list_active_projects

List all active projects assigned to the authenticated user, including their associated tasks. Returns a concise, readable format by default to minimize context usage.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID
• format (optional): Output format - 'compact' (default) for concise view or 'full' for complete JSON

Example Response (Compact Format - Default): ``` Client: Acme Corp → Website Redesign (project_id: 14308070) Tasks: Design (8083367), Development (8083368), Testing (8083369)

Client: 123 Industries → Online Store - Phase 1 (project_id: 14308069) Tasks: Graphic Design (8083365), Programming (8083366) ```

Example Response (Full Format): ``json [ { "id": 12345, "project": { "id": 67890, "name": "My Project", "code": "PROJ" }, "task_assignments": [ { "id": 111, "task": { "id": 222, "name": "Development" } } ], "is_project_manager": false, "budget": null, ... } ] ``

log_time

Create a time entry for a specific project and task.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID
• project_id (required): Project ID
• task_id (required): Task ID
• hours (required): Number of hours to log
• spent_date (optional): Date in YYYY-MM-DD format (defaults to today)
• notes (optional): Description of the work performed

Example Usage: ``json { "project_id": 67890, "task_id": 222, "hours": 2.5, "spent_date": "2026-02-04", "notes": "Implemented user authentication" } ``

Example Response: `` Success! Time entry created with ID: 123456789 ``

start_timer

Start a running timer for a specific project and task. The timer will track time until stopped.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID
• project_id (required): Project ID
• task_id (required): Task ID
• spent_date (optional): Date in YYYY-MM-DD format or relative date (defaults to today)
• notes (optional): Description of the work being performed

Example Usage: ``json { "project_id": 67890, "task_id": 222, "notes": "Working on user authentication" } ``

Example Response: `` Success! Timer started with ID: 123456789 ``

stop_timer

Stop a running timer. This uses Harvest's dedicated /stop endpoint to calculate hours based on elapsed time.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID
• time_entry_id (required): The ID of the running timer to stop

Example Usage: ``json { "time_entry_id": 123456789 } ``

Example Response: ``` Success! Timer stopped.

Project: My Project Task: Development Total time logged: 2.5 hours Date: 2026-02-12 ```

restart_timer

Restart a previously stopped timer. This uses Harvest's dedicated /restart endpoint to resume tracking.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID
• time_entry_id (required): The ID of the stopped timer to restart

Example Usage: ``json { "time_entry_id": 123456789 } ``

Example Response: ``` Success! Timer restarted.

ID: 123456789 Project: My Project Task: Development Date: 2026-02-12 ```

get_running_timer

Check if there's a timer currently running and see elapsed time.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID

Example Response: ``` Timer is running:

ID: 123456789 Project: My Project Task: Development Notes: Working on user authentication Elapsed: 1h 23m

[detailed JSON data] ```

delete_time_entry

Delete a specific time entry.

Parameters:

• access_token (optional): Harvest Personal Access Token
• account_id (optional): Harvest Account ID
• time_entry_id (required): The ID of the time entry to delete

Example Usage: ``json { "time_entry_id": 123456789 } ``

Example Response: `` Success! Time entry 123456789 has been deleted. ``

Development

Build the project

npm run build

Run in development mode (with ts-node)

npm run dev

Type checking only

npx tsc --noEmit

Project Structure

harvest-mcp/
├── index.ts          # Main server implementation
├── build/            # Compiled JavaScript output
│   └── index.js      # Entry point for MCP clients
├── package.json      # Dependencies and scripts
├── tsconfig.json     # TypeScript configuration
└── README.md         # This file

Usage with Claude Desktop

Once configured, you can use natural language to interact with Harvest:

Example interactions:

• "What projects am I assigned to in Harvest?"
• "Show me my time entries for today"
• "How many hours have I logged today?"
• "Show me my time entries for last Monday" (2026-02-03)
• "Get all time entries from February 1st to February 5th"
• "Show me time entries for project 67890 this week"
• "Log 3 hours to project 12345, task 222 with notes 'Fixed authentication bug'"
• "Start a timer for project 67890, task 222"
• "Is a timer running?"
• "Stop my current timer"
• "Restart timer 123456789"
• "Delete time entry 123456789"
• "Show me my Harvest profile"

Troubleshooting

Server not connecting

• Ensure the build step completed successfully (npm run build)
• Verify the absolute path in your MCP config points to build/index.js
• Restart your MCP client after configuration changes

Authentication errors

• Double-check your Personal Access Token and Account ID
• Ensure credentials are correctly set in environment variables or passed with tool calls
• Verify your Harvest account has API access enabled

Missing projects or tasks

• Ensure you're assigned to the projects in Harvest
• Only active projects are returned by list_active_projects
• Check that your user has the necessary permissions

API Reference

This server uses the Harvest API v2. Key endpoints:

• GET /users/me - Current user information
• GET /users/me/project_assignments - User's project assignments
• GET /time_entries - Retrieve time entries
• POST /time_entries - Create a time entry or start a timer
• PATCH /time_entries/{id}/stop - Stop a running timer
• PATCH /time_entries/{id}/restart - Restart a stopped timer
• DELETE /time_entries/{id} - Delete a time entry

License

ISC

Author

Sebastiaan Pfennigwerth

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.