# File input element

Allows user to upload files.

| | |
|---|---|
| **Type** | `file_input` |
| **Available in** | Modals, Home tab |
| **Works in blocks** | [Input block](https://workstation.repzo.com/docs/developers/block-kit/blocks/input-block) |

## Usage

Use the file input inside an [input block](https://workstation.repzo.com/docs/developers/block-kit/blocks/input-block). Each file is uploaded to Repzo storage as soon as it's picked; when the person submits the modal, your app receives the files in `view.state.values[block_id][action_id]`:

```json
{
  "type": "file_input",
  "files": [
    {
      "id": "<media id>",
      "name": "northwind-contract-signed.pdf",
      "mimetype": "application/pdf",
      "size": 284113,
      "url_private": "https://<your workspace host>/api/bot/files/<media id>?exp=…&sig=…"
    }
  ]
}
```

To download a file, `GET` its `url_private` with your app's token (`Authorization: Bearer foxa-…`, an app of the same workspace) and follow redirects — the response may redirect to a short-lived storage link. Each `url_private` works for **7 days**; copy the file if you need it longer.

Before calling your app, Repzo checks that a required input has at least one file and that there are no more than `max_files` ("Attach at most 3 files."). Every file id is checked on the server too: it must be a file that reader uploaded in this workspace.

## Fields

| Field | Type | Description | Required? |
|---|---|---|---|
| `type` | String | The type of element. In this case `type` is always `file_input`. | Required |
| `action_id` | String | An identifier for the input value when the parent view is submitted. You can use this when you receive a `view_submission` payload to identify the value of the input element (`view.state.values[block_id][action_id]`). Should be unique among all other `action_id`s in the containing block. Maximum length is 255 characters. If you leave it out, Repzo generates one. | Optional |
| `filetypes` | String[] | An array of valid file extensions (for example `pdf`, `png`) that will be accepted for this element. All file extensions will be accepted if `filetypes` is not specified. This check is for convenience only — check the files you receive yourself. | Optional |
| `max_files` | Integer | Maximum number of files that can be uploaded for this `file_input` element. Minimum of 1, maximum of 10. Defaults to 10 if not specified. | Optional |

> **How Repzo Chat differs from Slack**
>
> - Files are stored in Repzo, not Slack. The file objects carry only `id`, `name`, `mimetype`, `size` and `url_private`, and no `files:read` scope is needed — your app token and the signed link are enough.
> - The upload size follows the workspace's upload limits rather than Slack's 100 MB.
> - An input block holding a file input can't use `dispatch_action` (reported as a warning).
> - Works in the Home tab as well as in modals.
> - In a message, an input block is shown as a disabled stand-in and the API returns a warning instead of refusing the message.

## Examples

### A file input in a form

This example belongs in a modal view — the screenshot shows it in a modal.

```json
{
  "blocks": [
    {
      "type": "input",
      "block_id": "signed_contract",
      "label": {
        "type": "plain_text",
        "text": "Signed contract"
      },
      "element": {
        "type": "file_input",
        "action_id": "contract_files",
        "filetypes": [
          "pdf",
          "jpg",
          "png"
        ],
        "max_files": 3
      },
      "hint": {
        "type": "plain_text",
        "text": "PDF or photos of the signed pages, up to 3 files."
      }
    }
  ]
}
```

## Related

- [Block elements](https://workstation.repzo.com/docs/developers/block-kit/elements)
- [Block Kit overview](https://workstation.repzo.com/docs/developers/block-kit)