--- title: "REST API v4 and webhooks to connect your systems | attendo" description: "The attendo REST API v4: documents, customers, contracts, assets and projects, with one key per integration, per-operation permissions and signed webhooks." url: "https://attendo.me/en/integrations/rest-api-and-webhooks" lang: "en" --- # REST API and webhooks: your system talks to attendo If your system is not on the list, this is for you. REST API v4 reads and writes in attendo, webhooks notify your systems when something changes, and a flow step calls any API without coding. Status - One key per integration - Permissions by area and by operation - Interactive documentation attendo REST API - between attendo and your system, both ways **Documents, customers and assets** Your system reads and writes - from attendo to your system **Signed webhooks** attendo notifies you when something changes - from your system to attendo **Flow triggers** Your system starts an attendo flow ## Every Monday, someone exports to Excel No company lives in a single tool. The ERP wants to know what was done in the field, the website wants to open tickets and the dashboard wants real times. Without an API, someone exports to Excel every Monday. With the API, each system talks to attendo directly and only about what it needs. You create one key per integration, give it only what it needs, and know who called, for what and when. ## What it does, piece by piece Three pieces that work together: REST API v4, webhooks and the HTTP step in flows. ### What you can read and write Documents and their history, customers, contacts and contracts, quotes, orders and delivery notes, assets, projects, flows and checklists. Also requesters, field by field, scheduling, tasks, forms and mailing list sign-ups. Links to files are signed and expire after an hour. ### One key per integration Each key with its name, expiry, owner and rate limit. You pause or revoke one without touching the others. ### Permissions by area and by operation Each key can only do what you allow, and it is checked on every request. There are starting packages: read-only, field, sales, ERP and AI assistant. ### On behalf of a person An integration can act on behalf of a user: what it writes is recorded in their name, and it only sees what that person sees on screen. ### Signed webhooks attendo notifies your systems when a document is created, closed, answered or changes status. Also when an asset is edited, a form is submitted or a customer, contact or contract changes. When a customer is deleted, the notification carries only its identity. ### Flows that call any API A flow step calls any REST API with the document’s data, and your system starts an attendo flow with one call. The OpenAPI documentation is interactive: you try the calls from the browser before writing a line of code. And an API activity screen shows requests, webhook deliveries and their errors. ## What travels, and in which direction With the same rules as the screen: a tag brings its checklists along, and a document uses up its series number. What travels between attendo and REST API, in which direction and when | Data | Direction | When | | --- | --- | --- | | Documents, history and attachments | from attendo to your system | When your system asks for them | | New documents and changes | from your system to attendo | When your system sends them. With an idempotency key, a retry does not create another one | | Customers, contacts and contracts | between attendo and your system, both ways | When they are requested or sent | | Assets, plans and projects | between attendo and your system, both ways | When they are requested or sent | | Change notifications (webhooks) | from attendo to your system | Near real time, with history and retry | | Flow trigger | from your system to attendo | When your system calls | ## How to get started It is set up in Settings, with no involvement from us. The integration that uses it is built by your technical team or a partner, and we can support you if you need it. Status ### What you need - An attendo administrator to create the key - An HTTP client in your system: no library required - To receive webhooks, an HTTPS address that answers within a few seconds **Typical effort.** Creating a key takes minutes. The effort is in the integration that uses it: your technical team or a partner builds it. ### Step 1 · Create the key With the integration’s name, its expiry, just the permissions it needs and an owner. The secret is shown only once. ### Step 2 · Try it in the documentation You authorize the key in the interactive documentation and try the calls before coding. ### Step 3 · Subscribe to webhooks You choose the events, store the signing secret and send a test to your receiver. ### Step 4 · Monitor the first week The API activity screen tells you which requests arrived, which deliveries failed and why. ## What it does not do - **Instance configuration** Document types, fields and permissions are configured on screen, not through the API. - **Creating users** Through the API, users are listed, activated and deactivated; they are created on screen. - **Amounts on its own** Prices, taxes and numbering come from the same calculations as the screen. - **Every change by webhook** There are events for documents, assets, forms, customers, contacts and contracts. For anything else, your system reads the history through the API. - **Order of notifications** Your receiver must accept repeated or out-of-order notifications. ## What goes with it - [attendo + MCP](https://attendo.me/en/integrations/mcp): Your AI assistant queries attendo with each person’s permissions. - [attendo Flows](https://attendo.me/en/flows): Flows, approvals and forms without code. - [Technology](https://attendo.me/en/technology): Architecture, deployment and API. - [Security](https://attendo.me/en/security): Data in the EU, permissions and traceability. [All integrations](https://attendo.me/en/integrations) Every connection, with its real status. ## Frequently asked questions ### Which version should I use if I start today? API v4. It includes everything from the earlier versions, which are retired on March 31, 2027. ### Can I give an integration read-only access to customers? Yes. You give the key read access to customers and, if you want to go further, restrict it by operation. ### What if a key leaks? You revoke it in Settings and it stops working instantly. Every other integration keeps working. ### How many calls can I make? 120 per minute per key by default, which can be raised per key or for the whole instance. ### How do I know a notification comes from attendo? Each webhook is signed with your secret. Your receiver checks the signature and rejects old notifications. ### Are there client libraries? It is REST with JSON: any HTTP client works. ## Tell us what you want to connect We will show you what the API would do with your system and which part your technical team would take on. - With your operation, not a generic demo - A real person from our team replies - No cold calls afterwards Would you rather talk first? - Phone [+34 910 053 530](tel:+34910053530) - Email [sales@attendo.me](mailto:sales@attendo.me) - Monday to Thursday 9:30 AM to 6:30 PM and Friday 9:30 AM to 2:30 PM (Spain time)