--- title: "Connect Google Calendar and Harpoon - APIANT.ai" description: "When \"Attendee Response Changed\" fires in Google Calendar, your agent runs \"Add Invoice\" in Harpoon." canonical: "https://apiant.ai/connect/google-calendar-to-harpoon" --- # Connect Google Calendar and Harpoon When **Attendee Response Changed** fires in [Google Calendar](https://apiant.ai/connections/google-calendar), your agent runs **Add Invoice** in [Harpoon](https://apiant.ai/connections/harpoon), or **New Client** in Harpoon to **Create Event** in Google Calendar. Describe the whole flow and it is built, tested on every scenario and kept running. Google Calendar **6** triggers Google Calendar **45** actions Harpoon **9** triggers Harpoon **46** actions What the catalog holds today. Ask for anything missing and your agent reads the API documentation and adds it. ## What do you want Google Calendar and Harpoon to do together? Give your AI client this address. `https://mcp.apiant.ai` One connection does both: ask your client to act in an app once, or have it build an automation that keeps running. Any client that takes a remote MCP server. Nothing to install. Create your free account, then sign in once in your browser. ### Set it up in your client ### Claude Code Run this in the directory you want to work in. `claude mcp add --transport http -s project apiant-ai https://mcp.apiant.ai` Start Claude Code there, approve the server, and sign in in the browser page it opens. [Claude Code guide (opens in a new tab)](https://apiant.ai/docs/mcp/claude-code) ### Claude, web and desktop Open Customize, then Connectors, then Add custom connector, and paste the address. On Team and Enterprise an owner adds it first. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Cursor Add the address to your MCP configuration as a server URL. Cursor signs you in in your browser. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Zed Open Settings, then AI, then MCP Servers, then Add Server, then Add Remote Server. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Codex and the ChatGPT desktop app Open Settings, then MCP servers, then Add server, and choose Streamable HTTP. From the terminal, Codex takes the address with its own add command and then signs you in. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) ### Any other MCP client Paste the address where the client asks for a remote MCP server URL, and name the server apiant-ai where it lets you. APIANT's skills reach the client over the same connection. [Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp) Example flows ## What Google Calendar and Harpoon can do together ### From Google Calendar to Harpoon - When **Attendee Response Changed** in Google Calendar then **Add Invoice** in Harpoon - When **Event Created** in Google Calendar then **Add Lead Source** in Harpoon ### From Harpoon to Google Calendar - When **New Client** in Harpoon then **Create Event** in Google Calendar - When **New Contact** in Harpoon then **Update Event** in Google Calendar Starting points drawn from the triggers and actions in the catalog today. Describe the flow you need, at any depth, and your agent builds it and tests every scenario before it ships. Everything your agent can do with Google Calendar and Harpoon ## Triggers and actions 15 triggers · 91 actions - Trigger **Attendee Response Changed** Polling trigger that fires when any attendee's RSVP changes to accepted, declined, or tentative. Returns attendee info and current status. - Trigger **Calendar Event Sync** Polling trigger that returns full event data including details, attendees, and metadata. For real-time notifications with basic info, use Calendar Event Changes (webhook). - Trigger **Event Canceled or Deleted** Triggers when a Google Calendar event is cancelled or deleted. Returns minimal data: event_id, summary (if available), and cancellation timestamp. - Trigger **Event Created** Polling trigger that fires when a new calendar event is created. Returns event ID, summary, start/end times, and organizer info. - Trigger **Event Starting Soon** Triggers when a calendar event is within a configured number of minutes from starting. Returns event details, time remaining, attendees, and join links when available. - Trigger **Event Updated** Triggers when an existing Google Calendar event is modified. Returns the event ID, change type, and the specific fields that changed with their previous and new values. - Action **Acl Delete** Deletes an access control rule from a Google Calendar. Use when you need to remove sharing permissions for a user, group, or domain. - Action **Acl Get** Retrieves a specific access control rule for a calendar. Use when you need to check permissions for a specific user, group, or domain. - Action **Acl Insert** Creates an access control rule for a calendar. Use when you need to grant sharing permissions to a user, group, or domain. - Action **Acl List** Retrieves the list of access control rules (ACLs) for a specified calendar, providing the necessary 'rule_id' values required for updating specific ACL rules. - Action **Acl Patch** Updates an existing access control rule for a calendar using patch semantics (partial update). This allows modifying specific fields without affecting other properties. IMPORTANT: The ACL rule must already exist on the calendar. This action cannot create new rules. If you receive a 404 Not Found error, the rule does not exist - use ACL insert to create it first, or use ACL list to verify available rules. Each patch request consumes three quota units. For domain-type ACL rules, if PATCH fails with 500 error, this action will automatically fallback to UPDATE method. - Action **Acl Update** Updates an access control rule for the specified calendar. - Action **Acl Watch** Tool to watch for changes to ACL resources. Use when you need to set up real-time notifications for access control list modifications on a calendar. - Action **Batch Events** Execute up to 1000 event mutations (create/patch/delete) in one Google Calendar HTTP batch request with per-item status/results. Use this to materially reduce round-trips for bulk operations like migrations, cleanup, or large-scale updates. - Action **Calendar List Delete** Tool to remove a calendar from the user's calendar list. Use when you need to unsubscribe from or hide a calendar from the user's list. - Action **Calendar List Get** Retrieves metadata for a SINGLE specific calendar from the user's calendar list by its calendar ID. This action requires a calendarId parameter and returns details about that one calendar only. NOTE: This does NOT list all calendars. To list all calendars in the user's calendar list, use GOOGLECALENDAR_CALENDAR_LIST_LIST instead. - Action **Calendar List Insert** Inserts an existing calendar into the user's calendar list. - Action **Calendar List Patch** Updates an existing calendar on the user's calendar list using patch semantics. This method allows partial updates, modifying only the specified fields. - Action **Calendar List Update** Updates an existing entry on the user\'s calendar list. - Action **Calendar List Watch** Watch for changes to CalendarList resources using push notifications. Use this to receive real-time updates when calendar list entries are modified. - Action **Calendars Delete** Deletes a secondary calendar. use calendars.clear for clearing all events on primary calendars. - Action **Calendars Update** Updates metadata for a calendar. - Action **Channels Stop** Tool to stop watching resources through a notification channel. Use when you need to discontinue push notifications for a specific channel subscription. - Action **Create Calendar** Creates a new secondary Google Calendar with the specified title and optional settings. Use this action when you need to create a new calendar for organizing events separately from the primary calendar. The authenticated user becomes the owner of the newly created calendar. Optional parameters include description, location, and timezone. - Action **Create Event** Creates an event on a google calendar, needing rfc3339 utc start/end times (end after start) and write access to the calendar. by default, adds the organizer as an attendee unless exclude organizer is set to true. - Action **Delete Event** Deletes a specified event by `event id` from a google calendar (`calendar id`); this action is idempotent and raises a 404 error if the event is not found. - Action **Duplicate Calendar** Creates a new, empty google calendar with the specified title (summary). - Action **Events Get** Retrieves a SINGLE event by its unique event_id (REQUIRED). This action does NOT list or search events - it fetches ONE specific event when you already know its ID. If you want to list events within a time range, search for events, or filter by criteria like time_min/time_max, use GOOGLECALENDAR_EVENTS_LIST instead. - Action **Events Import** Tool to import an event as a private copy to a calendar. Use when you need to add an existing event to a calendar using its iCalUID. Only events with eventType='default' can be imported. - Action **Events Instances** Returns instances of the specified recurring event. - Action **Events List** Returns events on the specified calendar. - Action **Events List All Calendars** Return a unified event list across all calendars in the user's calendar list for a given time range. Use when you need a single view of all events across multiple calendars. An inverted or incorrect time range silently returns empty results rather than an error. An empty `items` list means no events matched the filters—adjust `time_min`, `time_max`, or `q` before concluding no events exist. - Action **Events Move** Moves an event to another calendar, i.e., changes an event's organizer. - Action **Events Watch** Watch for changes to events resources. - Action **Find Event** Finds events in a specified google calendar using text query, time ranges (event start/end, last modification), and event types; ensure `timemin` is not chronologically after `timemax` if both are provided. - Action **Find Free Slots** Finds free/busy time slots in google calendars for specified calendars within a defined time range (defaults to the current day utc if `time min`/`time max` are omitted), enhancing busy intervals with event details; `time min` must precede `time max` if both are provided. - Action **Free Busy Query** Returns free/busy information for a set of calendars. - Action **Get Calendar** Retrieves a specific google calendar, identified by `calendar id`, to which the authenticated user has access. - Action **Get Current Date Time** Gets the current date and time, allowing for a specific timezone offset. - Action **List Acl Rules** Retrieves the list of access control rules (acls) for a specified calendar, providing the necessary 'rule id' values required for updating specific acl rules. - Action **List Calendars** Retrieves calendars from the user's google calendar list, with options for pagination and filtering. - Action **Patch Calendar** Partially updates (patches) an existing google calendar, modifying only the fields provided; `summary` is mandatory and cannot be an empty string, and an empty string for `description` or `location` clears them. - Action **Patch Event** Updates specified fields of an existing event in a google calendar using patch semantics (array fields like `attendees` are fully replaced if provided); ensure the `calendar id` and `event id` are valid and the user has write access to the calendar. - Action **Quick Add** Parses natural language text to quickly create a basic google calendar event with its title, date, and time, suitable for simple scheduling; does not support direct attendee addition or recurring events, and `calendar id` must be valid if not 'primary'. - Action **Remove Attendee** Removes an attendee from a specified event in a google calendar; the calendar and event must exist. - Action **Settings Get** Tool to return a single user setting for the authenticated user. Use when you need to retrieve a specific calendar setting value. - Action **Settings List** Returns all user settings for the authenticated user. - Action **Settings Watch** Watch for changes to settings resources. - Action **Sync Events** Synchronizes google calendar events, performing a full sync if no `sync token` is provided or if a 410 gone error (due to an expired token) necessitates it, otherwise performs an incremental sync for events changed since the `sync token` was issued. - Action **Update Acl Rule** Updates an access control rule for the specified calendar. - Action **Update Event** Updates an existing event by `event id` in a google calendar; this is a full put replacement, so provide all desired fields as unspecified ones may be cleared or reset. - Trigger **New Client** Triggered when a new client is created in Harpoon. - Trigger **New Contact** Triggered when a new contact is created in Harpoon. - Trigger **New Expense** Triggered when a new expense is created in your Harpoon account. - Trigger **New Expense Category** Triggered when a new expense category is created in Harpoon. - Trigger **New Invoice** Triggered when a new invoice is created in Harpoon. - Trigger **New Payment** Triggered when a new payment is recorded in your Harpoon account. - Trigger **New Project** Triggered when a new project is created in Harpoon. - Trigger **New Task Category** Triggered when a new task category is added in your Harpoon account. - Trigger **New Time Entry** Triggered when a new time entry is logged in Harpoon. - Action **Add Credit Entry** Creates a new credit entry on a client's account in Harpoon, recording an amount, a date and an optional note or originating invoice. Returns the credit entry that was created. - Action **Add Invoice** Creates a new invoice in Harpoon for a client or project, with an invoice number, issue date, and optional line items. Returns the invoice that was created. - Action **Add Lead Source** Creates a new lead source in Harpoon, so new clients can be tagged with where they came from. Returns the lead source that was created. - Action **Add Note** Adds a note to a client, project or invoice in Harpoon. Returns the note that was created. - Action **Add Team** Creates a new team in your Harpoon account. Harpoon populates the new team from your account details; the API accepts no team attributes on creation. - Action **Clone Time Entry** Creates a copy of an existing time entry in Harpoon. The copy keeps the original's project, task and description, and starts with today's date and zero hours logged. - Action **Create Contact** Creates a contact person under a Harpoon client, with their name, email address, and phone number. Returns the contact that was created. - Action **Create Expense** Records a one-off expense in Harpoon with its date, amount, and vendor, optionally attributed to a client, project, or expense category. Returns the expense that was created. - Action **Create Expense Category** Creates a new expense category in your Harpoon account so expenses can be grouped under it. - Action **Create Project** Creates a project in Harpoon for a client, with its budget, rate, and start and end dates. Returns the project that was created. - Action **Create Time Entry** Logs hours worked in Harpoon for a team member on a given date, optionally against a client or project. Returns the time entry that was created. - Action **Delete Client** Deletes a client from your Harpoon account. - Action **Delete Expense** Permanently deletes an expense from your Harpoon account. - Action **Delete Invoice** Permanently removes an invoice from Harpoon. Returns Harpoon's confirmation that the invoice was deleted. - Action **Delete Note** Deletes a note from your Harpoon account. - Action **Delete Recurring Expense** Deletes a recurring expense template from Harpoon by its id, so it stops generating new expenses. - Action **Delete Recurring Invoice** Stops and removes a recurring invoice schedule in Harpoon so it no longer generates invoices. Returns Harpoon's confirmation that it was deleted. - Action **Delete Time Entry** Deletes a time entry from your Harpoon account. - Action **Get Client** Returns a single client from your Harpoon account, including its name, contact details and other stored attributes. - Action **Get Client Credits** Returns a client's credit entries in Harpoon, along with the credit still available on the account. - Action **Get Contact** Returns a single Harpoon contact, including their name, email address, phone number, and the client they belong to. - Action **Get Estimate** Returns a single estimate from your Harpoon account, including its client, line items, totals and status. - Action **Get Expense** Returns a single expense from your Harpoon account, including its amount, date, vendor, category and the client or project it is attached to. - Action **Get Expense Category** Returns a single Harpoon expense category with every detail it carries, including its name and budget settings. - Action **Get Invoice** Fetches one invoice from Harpoon by its id, with its client, line items and payment totals. An error occurs if the invoice is not found. - Action **Get Lead Source** Returns a single lead source from your Harpoon account. - Action **Get Project** Returns a single project from your Harpoon account, including its client, budget and status. - Action **Get Recurring Expense** Fetches one recurring expense template from Harpoon by its id, with its vendor, amount, frequency and schedule. An error occurs if it is not found. - Action **Get Recurring Invoice** Returns a single recurring invoice schedule from Harpoon, including its client, frequency, dates, and line items. - Action **Get Task** Returns a single task category from your Harpoon account, including its name and hourly rate. - Action **Get Team** Returns a single team from your Harpoon account, including its name, email address, phone, address, owner and whether it is active. - Action **Get Time Entry** Returns a single tracked time entry from your Harpoon account, including its date, hours, client, project and notes. - Action **List Contacts** Returns the contacts in your Harpoon account, including each contact's name, email address and phone number. - Action **List Estimates** Returns the estimates in a Harpoon account, optionally narrowed to a year, client, project, status, or search text. - Action **List Expense Categories** Returns the expense categories set up in Harpoon, each with its budget settings. - Action **List Expenses** Returns the expenses in your Harpoon account, optionally narrowed by date range, client, project, category, billing status or search text. - Action **List Invoices** Returns the invoices in your Harpoon account, optionally narrowed by year, client, project, status or a search term. - Action **List Projects** Returns the projects in a Harpoon account, with their client, budget, rate, and dates. - Action **List Teams** Returns the teams in your Harpoon account, along with the total number of teams found. - Action **List Time Entries** Returns time entries from your Harpoon account — either the timers running now or logged history for a date range — optionally narrowed by client, project, task, team member or billing status. - Action **Update Expense** Updates an existing expense in your Harpoon account. Only the values you supply are changed. - Action **Update Invoice** Updates an existing invoice in your Harpoon account. Only the values you supply are changed. - Action **Update Project** Updates an existing project in Harpoon — its name, client, billing type, status, dates, budget and task rates. Returns the updated project. - Action **Update Recurring Expense** Updates a recurring expense in Harpoon — its vendor, amount, frequency, category, dates, and status. Anything left blank keeps its current value. Returns the updated recurring expense. - Action **Update Recurring Invoice** Updates an existing recurring invoice template in your Harpoon account. Only the values you supply are changed. - Action **Update Time Entry** Updates an existing time entry in Harpoon — its date, hours, description, project, task or billing state. ## Each app on its own - [ **Google Calendar** Google Calendar is a time management tool providing scheduling features, event reminders, and integration...](https://apiant.ai/connections/google-calendar) - [ **Harpoon** Harpoon is a financial planning, scheduling, time-tracking, invoicing, and budgeting platform for...](https://apiant.ai/connections/harpoon) Reviews ## What our customers say ## More from Google Calendar - [ **Google Calendar to HubSpot** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/google-calendar-to-hubspot) - [ **Google Calendar to Salesforce** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/google-calendar-to-salesforce) - [ **Google Calendar to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/google-calendar-to-slack) - [ **Google Calendar to Google Sheets** Google Sheets](https://apiant.ai/connect/google-calendar-to-google-sheets) - [ **Google Calendar to Stripe** Stripe is a payment processing platform for online businesses.](https://apiant.ai/connect/google-calendar-to-stripe) - [ **Google Calendar to Shopify** Shopify is a commerce platform for online stores and retail point-of-sale.](https://apiant.ai/connect/google-calendar-to-shopify) ## More into Harpoon - [ **ActiveCampaign to Harpoon** ActiveCampaign is a marketing automation, email marketing, and CRM platform.](https://apiant.ai/connect/activecampaign-to-harpoon) - [ **Notion to Harpoon** A new tool that blends your everyday work apps into one. It's the all-in-one workspace for you and your team.](https://apiant.ai/connect/notion-to-harpoon) - [ **Airtable to Harpoon** Organize anything with Airtable, a modern database created for everyone.](https://apiant.ai/connect/airtable-to-harpoon) - [ **Asana to Harpoon** Asana is a collaborative information manager for workspace.](https://apiant.ai/connect/asana-to-harpoon) - [ **ClickUp to Harpoon** ClickUp is an all-in-one app to plan, track, and manage your work in a beautifully intuitive environment.](https://apiant.ai/connect/clickup-to-harpoon) - [ **Freshdesk to Harpoon** Freshdesk is a cloud-based customer support and helpdesk platform.](https://apiant.ai/connect/freshdesk-to-harpoon) Questions ## Google Calendar and Harpoon, answered ### ### What can start an automation from Google Calendar? Any of Google Calendar's 6 triggers in the catalog, including Attendee Response Changed, Event Created, Event Updated and Calendar Event Sync. Describe the moment in plain language and your agent picks the right one. ### ### What can your agent do in Harpoon when something happens in Google Calendar? Any of Harpoon's 46 actions, including Create Contact, Create Expense, Create Expense Category and Create Project. Your agent maps the data both ways and tests every scenario before it ships. ### ### Can it also run from Harpoon to Google Calendar? Yes. When something happens in Harpoon, your agent can act in Google Calendar too. This page covers both directions: Harpoon's triggers and Google Calendar's actions are listed here as well. ### ### Do I have to build a connector for Google Calendar or Harpoon? No. Both are in the catalog with their triggers and actions. You describe the automation; your agent builds it, tests every scenario and keeps it running. ### ### Can my AI client use Google Calendar and Harpoon without building an automation? Yes. With your AI client connected to APIANT, ask it to do something in either app once and it runs that action on the spot. Ask for an automation and your agent builds it, tests every scenario and keeps it running. One connection covers both. ### ### What happens when something fails? Your agent works that out for you. It plans the failure paths along with the happy path, then tests every scenario before it ships. ### ### Is there a free plan? Yes. Every plan includes the agent, including free, and building from your own AI client spends no assistant credits.