--- title: "Connect Cal.com to fastbill - APIANT.ai" description: "When \"Booking Created\" fires in Cal.com, your agent runs \"Add Payment for Invoice\" in fastbill." canonical: "https://apiant.ai/connect/cal-com-to-fastbill" --- # Connect Cal.com to fastbill When **Booking Created** fires in [Cal.com](https://apiant.ai/connections/cal-com), your agent runs **Add Payment for Invoice** in [fastbill](https://apiant.ai/connections/fastbill). Describe the whole flow and it is built, tested on every scenario and kept running. Cal.com **5** triggers fastbill **18** actions What the catalog holds today. Ask for anything missing and your agent reads the API documentation and adds it. ## What do you want Cal.com and fastbill 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 Cal.com can start in fastbill - When **Booking Created** in Cal.com then **Add Payment for Invoice** in fastbill - When **Out of Office Created** in Cal.com then **Create Customer** in fastbill 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 Cal.com and fastbill ## Triggers and actions 5 triggers · 18 actions - Trigger **Booking Cancelled** Triggers when a booking is cancelled. - Trigger **Booking Created** Triggers when a new booking is created. - Trigger **Booking Rescheduled** Triggers when a booking is rescheduled. - Trigger **Meeting Ended** Triggers after meeting ends. - Trigger **Out of Office Created** Triggers when a new Out Of Office entry is created. - Action **Add Payment for Invoice** Adds full payment for invoice - Action **Add Payment for Revenue** Adds full payment for revenue - Action **Create Customer** Creates a new customer in FastBill - Action **Create Invoice** Creates a new invoice - Action **Create Offer** Creates a new offer in FastBill - Action **Create Revenue** Creates a revenue entry - Action **Delete Customer** Delete a FastBill customer by ID. - Action **Delete Invoice** Delete a FastBill invoice by ID. - Action **Delete Offer** Delete a FastBill offer/estimate by ID. - Action **Finalize Invoice** Converts an invoice draft to a final invoice - Action **Get Customer** Fetch a single FastBill customer by ID. - Action **Get Invoice** Fetch a single FastBill invoice by ID. - Action **Get Offer** Fetch a single FastBill offer/estimate by ID. - Action **Search Customer** Search for a Customer - Action **Search Invoice** Find an invoice - Action **Send Invoice by Email** Send an invoice by email - Action **Update Customer** Update fields on an existing FastBill customer. - Action **Update Invoice** Update fields on an existing (draft) FastBill invoice. ## Each app on its own - [ **Cal.com** Cal.com simplifies scheduling for individuals, teams, and developers with powerful features and integrations...](https://apiant.ai/connections/cal-com) - [ **fastbill** FastBill is a cloud app for German invoicing & accounting.](https://apiant.ai/connections/fastbill) Reviews ## What our customers say ## More from Cal.com - [ **Cal.com to Google Drive** Google Drive is a cloud storage solution for uploading, sharing, and collaborating on files across devices...](https://apiant.ai/connect/cal-com-to-google-drive) - [ **Cal.com to Cloudflare Trace** Cloudflare Trace is a free JSON wrapper over Cloudflare's edge trace endpoint that reports what Cloudflare...](https://apiant.ai/connect/cal-com-to-cloudflare-trace) - [ **Cal.com to Odoo CRM** Odoo is a powerful open source platform with dozens of apps to help you grow your business.](https://apiant.ai/connect/cal-com-to-odoo-crm) - [ **Cal.com to HubSpot** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/cal-com-to-hubspot) - [ **Cal.com to Salesforce** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/cal-com-to-salesforce) - [ **Cal.com to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/cal-com-to-slack) ## More into fastbill - [ **FreeAgent to fastbill** FreeAgent is cloud accounting software for small businesses and freelancers — manage contacts, invoices...](https://apiant.ai/connect/freeagent-to-fastbill) - [ **HubSpot to fastbill** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/hubspot-to-fastbill) - [ **Salesforce to fastbill** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/salesforce-to-fastbill) - [ **Slack to fastbill** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/slack-to-fastbill) - [ **Google Sheets to fastbill** Google Sheets is Google's online spreadsheet app for creating, editing and sharing spreadsheets.](https://apiant.ai/connect/google-sheets-to-fastbill) - [ **Gmail to fastbill** Gmail is Google’s email service, featuring spam protection, search functions, and seamless integration with...](https://apiant.ai/connect/gmail-to-fastbill) Questions ## Cal.com and fastbill, answered ### ### What can start an automation from Cal.com? Any of Cal.com's 5 triggers in the catalog, including Booking Created, Out of Office Created, Booking Rescheduled and Meeting Ended. Describe the moment in plain language and your agent picks the right one. ### ### What can your agent do in fastbill when something happens in Cal.com? Any of fastbill's 18 actions, including Create Customer, Create Invoice, Create Offer and Create Revenue. Your agent maps the data both ways and tests every scenario before it ships. ### ### Can it also run from fastbill to Cal.com? fastbill has no triggers in the catalog today, so automations start in Cal.com. If you need the other direction, ask: your agent reads fastbill's API documentation and adds it. ### ### Do I have to build a connector for Cal.com or fastbill? 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 Cal.com and fastbill without building an automation? Yes. With your AI client connected to APIANT, ask it to do something in fastbill 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.