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

# POST /multiupload — Upload Documents to Flow

> Upload one or more document file URLs to an existing verification flow. Atlas downloads each file, runs OCR extraction, and queues pairwise cross-document validation.

After initialising a flow with [POST /flow/init](/api-reference/verification/flow-init), submit all document URLs in a single call to this endpoint. Atlas will download each file, run OCR extraction, and queue cross-document validation automatically.

## Endpoint

```text theme={null}
POST /verification/multiupload
```

## Request headers

<ParamField header="Token" type="string" required>
  JWT access token obtained from [POST /authtoken](/api-reference/auth/generate-token).
</ParamField>

## Request body

<ParamField body="flow_uuid" type="string" required>
  The UUID returned by [POST /flow/init](/api-reference/verification/flow-init). Ties these uploads to the correct verification session.
</ParamField>

<ParamField body="file_urls" type="array" required>
  An array of file objects. You may include multiple documents in a single request.

  <Expandable title="file_urls item">
    <ParamField body="file_url" type="string" required>
      A publicly accessible URL (S3 pre-signed URL or equivalent) pointing to the document file. Atlas fetches the file directly from this URL.
    </ParamField>

    <ParamField body="document_id" type="string" required>
      Your own identifier for this document. Atlas echoes it back in the response and in all extraction results, letting you correlate Atlas output with your internal records.
    </ParamField>
  </Expandable>
</ParamField>

## Response

The response is an array with one entry per uploaded file.

<ResponseField name="file_uuid" type="string">
  Atlas's UUID for this specific file. Unique across all uploads.
</ResponseField>

<ResponseField name="batch_id" type="string">
  A batch identifier grouping all files submitted in this request (for example, `BATCH-30732-SIYKJ-20251121113228`).
</ResponseField>

<ResponseField name="document_id" type="string">
  The `document_id` you provided during upload, echoed back for easy correlation.
</ResponseField>

## Example

<CodeGroup>
  ```bash cURL theme={null}
  curl --request POST \
    --url https://api.helloatlas.in/v3/verification/multiupload \
    --header "Token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..." \
    --header "Content-Type: application/json" \
    --data '{
      "flow_uuid": "LOS-17cab13b-f437-49bc-9c08-55319b88b0eb",
      "file_urls": [
        {
          "file_url": "https://files.s3.ap-south-1.amazonaws.com/uploads/invoice.jpg",
          "document_id": "1"
        },
        {
          "file_url": "https://files.s3.ap-south-1.amazonaws.com/uploads/delivery-order.jpg",
          "document_id": "2"
        },
        {
          "file_url": "https://files.s3.ap-south-1.amazonaws.com/uploads/imei-closeup.jpg",
          "document_id": "3"
        }
      ]
    }'
  ```

  ```json 201 Created theme={null}
  [
    {
      "batch_id": "BATCH-30732-SIYKJ-20251121113228",
      "document_id": "1",
      "file_uuid": "03f03421-c933-46fc-a30c-ffb3ea8afd1d"
    },
    {
      "batch_id": "BATCH-30732-SIYKJ-20251121113228",
      "document_id": "2",
      "file_uuid": "03f03422-c933-46fc-a30c-ffb3ea8afd1d"
    },
    {
      "batch_id": "BATCH-30732-SIYKJ-20251121113228",
      "document_id": "3",
      "file_uuid": "03f03423-c933-46fc-a30c-ffb3ea8afd1d"
    }
  ]
  ```
</CodeGroup>

## Error responses

| Status | Meaning                                                                                                   |
| ------ | --------------------------------------------------------------------------------------------------------- |
| `400`  | `Missing or empty required parameters: ['flow_uuid']` — a required field is absent from the request body. |
| `401`  | `Invalid token` — the token is expired, revoked, or does not match any active session.                    |
| `422`  | External service failure (for example, Atlas could not reach the authentication URL you configured).      |

<Note>
  The `document_id` field is your primary way to match Atlas extraction results back to your own documents. Choose a value that is unique within the flow and meaningful in your system (for example, a database record ID).
</Note>