Harvest MCP Server

Instructions

Args:
    is_active: Pass true to only return active clients and false to return inactive clients

Implementation Reference

• harvest-mcp-server.py:205-217 (handler)

  The handler function that implements the list_clients tool. It constructs parameters based on the is_active filter and calls the shared harvest_request helper to fetch clients from the Harvest API, returning the JSON response.

  async def list_clients(is_active: bool = None):
      """List clients with optional filtering.
  
      Args:
          is_active: Pass true to only return active clients and false to return inactive clients
      """
      params = {}
      if is_active is not None:
          params["is_active"] = "true" if is_active else "false"
  
      response = await harvest_request("clients", params)
      return json.dumps(response, indent=2)

• harvest-mcp-server.py:204-204 (registration)

  The @mcp.tool() decorator registers the list_clients function as an MCP tool.

  @mcp.tool()

• harvest-mcp-server.py:21-43 (helper)

  Shared helper function used by list_clients (and other tools) to make authenticated HTTP requests to the Harvest API.

  async def harvest_request(path, params=None, method="GET"):
      headers = {
          "Harvest-Account-Id": HARVEST_ACCOUNT_ID,
          "Authorization": f"Bearer {HARVEST_API_KEY}",
          "User-Agent": "Harvest MCP Server",
          "Content-Type": "application/json",
      }
  
      url = f"https://api.harvestapp.com/v2/{path}"
  
      async with httpx.AsyncClient() as client:
          if method == "GET":
              response = await client.get(url, headers=headers, params=params)
          else:
              response = await client.request(method, url, headers=headers, json=params)
  
          if response.status_code != 200:
              raise Exception(
                  f"Harvest API Error: {response.status_code} {response.text}"
              )
  
          return response.json()