--- title: "Connect Sellsy to OnceOnly - APIANT.ai" description: "When \"New Company\" fires in Sellsy, your agent runs \"Add event\" in OnceOnly. Describe the whole flow and it is built, tested on every scenario and kept running." canonical: "https://apiant.ai/connect/sellsy-to-onceonly" --- # Connect Sellsy to OnceOnly When **New Company** fires in [Sellsy](https://apiant.ai/connections/sellsy), your agent runs **Add event** in [OnceOnly](https://apiant.ai/connections/onceonly). Describe the whole flow and it is built, tested on every scenario and kept running. Sellsy **9** triggers Sellsy **15** actions OnceOnly **11** actions What the catalog holds today. Ask for anything missing and your agent reads the API documentation and adds it. ## What do you want Sellsy and OnceOnly 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 Sellsy can start in OnceOnly - When **New Company** in Sellsy then **Add event** in OnceOnly - When **New Contact** in Sellsy then **Add policy** in OnceOnly 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 Sellsy and OnceOnly ## Triggers and actions 9 triggers · 26 actions - Trigger **Deleted Task** Triggers when a task is deleted. - Trigger **New Company** Triggers when a new company (client or prospect) is created. - Trigger **New Contact** Triggers when a new contact is created. - Trigger **New Opportunity** Triggers when a new opportunity is created. - Trigger **New Task** Triggers when a new task is created. - Trigger **Updated Company** Triggers when a company (client or prospect) is updated. - Trigger **Updated Contact** Triggers when a contact is updated. - Trigger **Updated Opportunity Status** Triggers when the status is changed on an opportunity. - Trigger **Updated Task** Triggers when a task is updated. - Action **Create Annotation** Creates a new annotation. - Action **Create Company** Creates a new company (prospect or client). - Action **Create Contact** Creates a new contact. - Action **Create Opportunity** Creates an opportunity. - Action **Create Task** Creates a new Task. - Action **Create/Update Company** Creates a new company (prospect or client). Make an update if we found an existing company with provided email. - Action **Create/Update Contact** Creates a new contact. Make an update if we found an existing contact with provided email. - Action **Delete Task** Deletes a Sellsy task. - Action **Find Company** Finds an existing company (prospect or client). - Action **Find Contact** Finds an existing contact. - Action **Get Opportunity** Returns one Sellsy opportunity by id. - Action **Get Task** Returns one Sellsy task by id. - Action **List Opportunity Pipeline Steps** Lists the steps of a pipeline; supplies the required step id for Create Opportunity. - Action **Update Opportunity** updates an existing opportunity's fields, including its status (open/won/lost/cancelled/...) and pipeline step; a status change fires the opportunity.status webhook event. - Action **Update Task** updates a task's title, description, due date, status etc.; fires task.updated. - Action **Add event** Adds an event to an agent run's timeline in OnceOnly, such as a step starting, a tool call, or a failure. - Action **Add policy** Creates or updates the governance policy for an agent, such as rate limits, spend limits and allowed or blocked tools. - Action **Add tool** Creates or updates a tool in your OnceOnly tool registry, pointing at your backend URL. Returns the saved tool without its secret. - Action **Check & Lock** Checks an idempotency key and locks it if it is new, telling you whether the event is a first occurrence or a duplicate. - Action **Delete tool** Permanently deletes a tool from your OnceOnly tool registry. - Action **Get policy** Returns the governance policy configured for an agent. - Action **Get run** Returns a run's timeline: the run id, the total number of events and the list of events recorded for it. - Action **Get tool** Returns the details of a registered tool by name, including its URL, scope, enabled state and retry settings. - Action **List policies** Returns every agent policy on the OnceOnly account, each with its agent id and policy settings. - Action **List runs** Returns the runs recorded on your OnceOnly account, with each run's latest status and event count. - Action **List tools** Returns the tools registered in your OnceOnly tool registry for a scope. ## Each app on its own - [ **Sellsy** Sellsy is a French SaaS that helps SMBs and VBEs manage sales, invoicing, marketing, and cash flow in one...](https://apiant.ai/connections/sellsy) - [ **OnceOnly** OnceOnly is an idempotency API that prevents duplicate automation runs by blocking repeated events in...](https://apiant.ai/connections/onceonly) Reviews ## What our customers say ## More from Sellsy - [ **Sellsy to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/sellsy-to-slack) - [ **Sellsy to Stripe** Stripe is a payment processing platform for online businesses.](https://apiant.ai/connect/sellsy-to-stripe) - [ **Sellsy to Shopify** Shopify is a commerce platform for online stores and retail point-of-sale.](https://apiant.ai/connect/sellsy-to-shopify) - [ **Sellsy to Trello** Trello is a visual collaboration tool that organizes projects into boards, lists, and cards.](https://apiant.ai/connect/sellsy-to-trello) - [ **Sellsy to Zoom** Zoom unifies cloud video conferencing, simple online meetings, group messaging, and a software-based...](https://apiant.ai/connect/sellsy-to-zoom) - [ **Sellsy to Twilio** Cloud communications platform for sending SMS/MMS messages, making and managing voice calls, and looking up...](https://apiant.ai/connect/sellsy-to-twilio) ## More into OnceOnly - [ **HubSpot to OnceOnly** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/hubspot-to-onceonly) - [ **Salesforce to OnceOnly** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/salesforce-to-onceonly) - [ **Slack to OnceOnly** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/slack-to-onceonly) - [ **Google Sheets to OnceOnly** Google Sheets](https://apiant.ai/connect/google-sheets-to-onceonly) - [ **Gmail to OnceOnly** Gmail is Google’s email service, featuring spam protection, search functions, and seamless integration with...](https://apiant.ai/connect/gmail-to-onceonly) - [ **Google Calendar to OnceOnly** Google Calendar is a time management tool providing scheduling features, event reminders, and integration...](https://apiant.ai/connect/google-calendar-to-onceonly) Questions ## Sellsy and OnceOnly, answered ### ### What can start an automation from Sellsy? Any of Sellsy's 9 triggers in the catalog, including New Company, New Contact, New Opportunity and New Task. Describe the moment in plain language and your agent picks the right one. ### ### What can your agent do in OnceOnly when something happens in Sellsy? Any of OnceOnly's 11 actions, including Add event, Add policy, Add tool and Check & Lock. Your agent maps the data both ways and tests every scenario before it ships. ### ### Can it also run from OnceOnly to Sellsy? OnceOnly has no triggers in the catalog today, so automations start in Sellsy. If you need the other direction, ask: your agent reads OnceOnly's API documentation and adds it. ### ### Do I have to build a connector for Sellsy or OnceOnly? 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 Sellsy and OnceOnly 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.