Apps cover the systems lots of businesses use. Custom Actions cover the one only you use: the field-service app you chose years ago, the booking system you built in-house, the database behind your customer portal.
With a Custom Action, the AI agent calls your API in the middle of a call, while the caller is still on the line.
One call, with your API in it
A caller rings because their heating has stopped. The agent finds them in your contacts, asks what’s wrong, and offers to book a visit. When they say yes, it creates the job in your field-service app and reads back the job number.
That last step is a Custom Action: one request to your system, which you built once in Crulon and gave to the agent.
An Action is one request
A Custom Action is one HTTPS request, such as “create a job” or “look up an order”. You build it in Custom Actions:
- Kind. READ fetches data; WRITE changes something.
- Parameters. The values the agent fills in from the conversation, such as the caller’s number or what’s wrong. Each has a type, whether it’s required, and where it goes: the body, the path, the query or a header.
- Method and URL.
GET,POST,PUT,PATCHorDELETE, to your endpoint. - Static params. Values you fix that the agent never sees or chooses, such as your account ID.
- Response fields. Which parts of your response the agent gets back. Pass it the job number and the arrival window, not the whole record.
The body can take two shapes. The default wraps the agent’s values with the Action’s name and details of the call, so one endpoint can handle several Actions. The other sends just the values, for an API that already exists and expects a plain body.
Credentials stay in Crulon
Save a credential once, as a bearer token, an API key in the header you name, or a username and password. After that it’s never shown again, not even to you. To change it, you replace it.
Each credential and each Action can be limited to the hosts you allow, so a credential is only ever sent to your own servers.
Test it before the agent sees it
Run test sends a real request with your credential and shows three things: what Crulon sent, what your endpoint returned, and what the agent would receive. It’s the one place you see your API’s real error message, so use it until the response looks right.
Drafts can be tested but agents can’t use them. Publish makes a version available, and published versions don’t change: to change one, publish the next version.
A Tool is what the agent uses
The agent doesn’t call Actions directly. You put one or more Actions into a Tool, with the conditions between them, such as “only create the job if the caller was found in our system”. The Tool has the description the agent reads to decide when to use it, so write it for the agent: what the Tool does and when it’s the right one.
Attach the Tool to an agent under Business Tools. Tools keep every published version, so you can roll back.
Changes wait for a yes
A WRITE Action is marked Destructive to start. Before a Tool that uses it runs, the agent says what it’s about to do and waits for the caller to agree: “I’ll book a visit for Thursday morning. Shall I go ahead?” Crulon adds a check of its own: the agent can’t run the Tool until it has marked that the caller said yes.
You can write the wording it uses for each Tool, and test it by talking to the agent in your browser.
When your API is down
The agent is told only that the Tool is unavailable; the details stay in Crulon for you. What the caller hears instead is set on the agent, per Tool, so it can say “I can’t book that right now, but I’ll have the office call you first thing.”
If a write times out, the agent tells the caller it can’t confirm whether it went through. Crulon doesn’t retry, so a request is never sent twice by surprise, but it’s still worth making your endpoint safe to call twice.
The limits
- HTTPS only, to public addresses. Private and internal addresses are blocked, and redirects aren’t followed.
- Up to 30 seconds per request; 10 if you don’t set it.
- JSON responses, up to 64 KB.
- 100 requests a minute per workspace, 50 per Action.
- 3 Custom Tools on Starter, 10 on Pro and 25 on Scale.
See the Custom Actions page, or the developer guide for the request format, headers and credentials in full.