Runs onWrit CloudDesktopSelf-hosted
On this page
AI fill form
The ai_fill_form step hands an entire form to the AI: it reads the fields on the page and fills them from the run inputs and credentials — useful for long or frequently rearranged forms.
In a workflow, this is a step object with "type": "ai_fill_form". Steps run in order, and each step can read the outputs of the steps before it. See the full workflows reference for the 30+ step types.
Writ runs on your own accounts, with your own credentials and data, on sites you are authorized to use.
Fields
| Field | Type | Description |
|---|---|---|
description | string | What the form is for and any constraints, in plain words. |
Example
A single ai_fill_form step as it appears in a workflow's steps array:
{
"type": "ai_fill_form",
"config": { "description": "Complete the checkout address form from the run inputs" }
}How it behaves
- Field values come from the declared inputs and credentials; the AI decides which value belongs in which field.
- For a single stubborn field, ai_fill is the smaller tool.
Where it runs
The ai_fill_form step executes wherever the run executes. On your local or BYO agent there is no compute charge and the agent can reach intranet-only systems; on Writ cloud the run is metered by running time (~$0.12 per browser-hour, from your plan’s included usage wallet.
What next
- Workflows - the full step vocabulary and the workflow object.
- Recorder - capture steps by clicking through a site.
- Managed endpoints - turn the workflow into a REST endpoint, or an MCP tool.