> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lithoblocks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Modal data binding

> Pre-fill modal form fields with data from the message that triggered the modal.

Data binding passes information from the Slack message into the modal so fields are pre-filled. Users see context-aware forms without re-entering data.

## Prerequisites

* Understanding of [Modal basics](/guides/modals-basics)
* Familiarity with [Placeholders](/guides/templates-placeholders)
* Experience with [Interactive buttons](/guides/interactive-buttons)

## How it works

1. The template is rendered with sample data (e.g. `{ user: { name: "John", email: "john@example.com" } }`)
2. The message is sent to Slack with data embedded in metadata
3. The user clicks a button that opens a modal
4. Data bindings are evaluated using the original message data
5. The modal opens with fields pre-filled

## Binding types

* **Simple values** — Map a placeholder path to a field (e.g. `user.name` → "Full name")
* **Array transformations** — Use an array in your data to populate select options
* **Computed values** — Concatenate or format data for a field

## Configure bindings

1. Create your modal and add input fields (see [Modal basics](/guides/modals-basics))
2. For each field you want to pre-fill, set a **data binding** path that matches your template data (e.g. `user.email`, `request.id`)
3. Connect the button to open this modal; when the message has that data, the modal will open with those fields filled

<Tip>
  Use the same data structure in your template's sample data and in your bindings so the modal receives the expected values.
</Tip>

## Next steps

<Card title="Modal submissions" icon="paper-plane" href="/guides/modals-submissions">
  Process form submit with webhooks and message updates.
</Card>