---
Source: https://docs.microblink.com/platform/capabilities/initialization-step
Title: Initialization step
Description: Configure the entry point and initial settings for verification workflows
---

# Initialization step

You can use the initialization step to provide data to the workflow in advance of any user interaction.
This could be used if you have existing data in your system that you want to confirm with other capabilities, for example [matching a face image against a selfie](../img-selfie-match).

![Custom input fields](/platform/img/custom-input-fields.png)

## Uploading document images

To upload a document image using the initialization step, select **raw document image** as the linked field.
Use **Raw document image front** or **Raw document image back**.

The Agent API expects a base64-encoded image:

```bash
base64 -i {your image} -o {output text file}
```

When executing the workflow itself (in the initial request towards the [proxy](/platform/proxy)), pass the base64-encoded image using the `formValues` object.

```json {5-7}
{
  "workflowId": "string",
  "platform": "string",
  "sdkVersion": "string",
  "formValues": {
    "imageFront": "/9j/4AAQSkZJRgABAQAASABIAAD/4QB...",
    "imageBack": "/9j/4AAQSkZJRgABAQAASABIAAD/4QB..."
  },
  "props": {},
  "consent": {}
}
```


In the example above, we used `imageFront` and `imageBack` as example names for these fields, but they could be called anything.
The important thing is to properly link them, as that allows other steps in the workflow to access them.


Last updated on Apr 16, 2026