--- title: "Connect Karbon to fastbill - APIANT.ai" description: "When \"New work item\" fires in Karbon, your agent runs \"Add Payment for Invoice\" in fastbill." canonical: "https://apiant.ai/connect/karbon-to-fastbill" --- # Connect Karbon to fastbill When **New work item** fires in [Karbon](https://apiant.ai/connections/karbon), 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. Karbon **1** trigger Karbon **16** actions 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 Karbon 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 Karbon can start in fastbill - When **New work item** in Karbon then **Add Payment for Invoice** in fastbill - When **New work item** in Karbon 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 Karbon and fastbill ## Triggers and actions 1 trigger · 34 actions - Trigger **New work item** Triggers when a new work item is created in Karbon. - Action **Add client group** Creates a new client group in Karbon, optionally with members, owner, manager and client team. - Action **Add note** Creates a note in Karbon, optionally assigned to a user and linked to work items, contacts, organizations or client groups. - Action **Add work item** Creates a new work item for a client in Karbon. - Action **Create Organization Contact** Creates a new Organization contact in Karbon. - Action **Create Person Contact** Creates a new person Contact in Karbon and returns the created Contact record. - Action **Find an Organization Contact** Finds Organization contacts in Karbon matching a full name, email address, external key or contact type, and returns the matching organizations. - Action **Find a Person Contact** Finds person contacts in Karbon by email address, full name, phone number, contact type or external key, and returns the matches. - Action **Get work item** Returns the details of a single Karbon work item, including its client, dates, status, fee settings and role assignments. - Action **List invoices** Returns the invoices in your Karbon account, optionally filtered by invoice status and sorted. - Action **List timesheets** Returns a list of timesheets from your Karbon account, optionally filtered by date, user, work item or status, with their time entries if requested. - Action **List users** Returns the users in your Karbon account, optionally filtered by name or email address. - Action **List work items** Returns the work items in your Karbon account, optionally filtered and sorted. - Action **Update client group** Renames an existing Karbon client group by changing its full name. - Action **Update Organization Contact** Updates the name or privacy level of an existing Organization contact in Karbon. - Action **Update Person Contact** Updates the name details or privacy level of an existing Person Contact in Karbon. - Action **Update work item** Updates a Karbon work item's title, description, dates, assignee, work type, role assignments or status. Fields left blank are not changed. - 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 - [ **Karbon** Karbon is the collaborative practice management platform for accounting firms.](https://apiant.ai/connections/karbon) - [ **fastbill** FastBill is a cloud app for German invoicing & accounting.](https://apiant.ai/connections/fastbill) Reviews ## What our customers say ## More from Karbon - [ **Karbon to Salesforce** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/karbon-to-salesforce) - [ **Karbon to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/karbon-to-slack) - [ **Karbon to Mailchimp** Mailchimp marketing automation and email platform.](https://apiant.ai/connect/karbon-to-mailchimp) - [ **Karbon to Stripe** Stripe is a payment processing platform for online businesses.](https://apiant.ai/connect/karbon-to-stripe) - [ **Karbon to Shopify** Shopify is a commerce platform for online stores and retail point-of-sale.](https://apiant.ai/connect/karbon-to-shopify) - [ **Karbon to QuickBooks Online** QuickBooks Online accounting — manage customers, invoices, bills, payments, vendors, expenses, and more via...](https://apiant.ai/connect/karbon-to-quickbooks-online) ## 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 ## Karbon and fastbill, answered ### ### What can start an automation from Karbon? Any of Karbon's 1 trigger in the catalog, including New work item. Describe the moment in plain language and your agent picks the right one. ### ### What can your agent do in fastbill when something happens in Karbon? 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 Karbon? fastbill has no triggers in the catalog today, so automations start in Karbon. 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 Karbon 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 Karbon and fastbill 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.