Expense Tracker MCP Server

Instructions

Implementation Reference

• main.py:150-166 (handler)

  The add_credit function is decorated with @mcp.tool() and handles adding credit to a user's account in the database.

  @mcp.tool()
  def add_credit(amount, user_name="default"):
      """
      Add credit to the user's account. By default updates 'default' user.
      Returns new credit amount.
      """
      try:
          with sqlite3.connect(DB_PATH) as conn:
              cursor = conn.cursor()
              # ensure user exists
              cursor.execute("INSERT OR IGNORE INTO users (name, credit) VALUES (?, ?)", (user_name, 0.0))
              cursor.execute("UPDATE users SET credit = credit + ? WHERE name = ?", (float(amount), user_name))
              cursor.execute("SELECT credit FROM users WHERE name = ?", (user_name,))
              new_credit = cursor.fetchone()[0]
              return {"status": "ok", "credit": new_credit}
      except Exception as e:
          return {"status": "error", "error": str(e)}