Build an application
with Extella
Start with one useful program and check it. Then add the ways to work with it and prepare the handover.
Start with one useful program
For example, a calculation over a file, a document conversion or a call to an external service. Describe the input and what a correct answer looks like, and prepare a small example you can check by hand.
How to save the program and call it again with other input is in Quick start and Programs. The code does not need to be generated again for each call.
Add the way you need to work with it
A window for parameters and buttons. An agent for asking in words. Another device if the calculation has to run where the files are: see Devices and handlers.
Prepare the handover
Build the app and check that another person can install it. The recipient works with their own copy; the author's changes are not carried over automatically. The full path for the report still needs an end-to-end test.
What the environment provides and what you write
| Task | Environment mechanism | Work on your build |
|---|---|---|
| Save and call a program | API operations and MCP tools | Code, parameters, checking the result |
| Run on a device | Device selection and the executor (Listener) | Language, handler, dependencies and permissions |
| Connect a third-party service | A call through a program | A wrapper or handler, access to the service API |
| Give a person a window | Apps and the desktop | The interface and its link to the program |