Update Application

Updates field values on an application — for example to pre-fill data you already hold before the applicant opens the form, or to sync a correction made in your system. Only fields can be updated through this endpoint; people, ownership, and documents are managed by the applicant in the Klara form.

PATCH /api/external/applications/{id}

Authentication

Requires an API key with applications:write scope. The application must belong to the organization associated with the API key.

Authorization: Bearer klara_{client_id}.{secret}

Path parameters

string

required

UUID of the application.

Request body

object

required

Key-value map of field values to set, keyed by field ID (e.g., company_name). Must contain at least one key.Every key must be a patchable field of the application’s configuration. Unknown field IDs, document-type fields, person-scoped fields (per-person fields like full_name or date_of_birth, which belong to person records), and confirmation attestations are rejected with a 400 listing the offending keys. Fields you don’t include are left untouched.Use the Field Catalog to discover the patchable field IDs, their types, and allowed option values for your configuration.

Value validation

Values are validated when you write them:

select values must be one of the field’s configured option values; multi_select values must be an array of them
boolean fields take a boolean, text/date/phone fields take a string, address fields take a structured address object
format rules configured on the field (patterns, phone format, address completeness) are applied

A failing value returns 400 with a per-field message. Sending null (or an empty string) clears a field. Required/presence checks still run at submission, not here — you can pre-fill a subset of fields freely.

Behavior

Writable states only — updates are accepted while the application is in created, sent, or in_progress. Once submitted, the data is frozen and this endpoint returns 400.
Status is never changed — pre-filling an application you’ve just created does not move it to in_progress; that happens when the applicant starts working on it.
No webhooks are emitted — your own updates are not echoed back to your webhook endpoints, even when they complete a stage.
Audited — every update is recorded in the application’s activity log, attributed to your API key.

Response

Returns 200 OK when the update is applied.

boolean

true when the update was applied.

string

UUID of the application.

string[]

The field IDs that were set.

Examples

Pre-filling company details

curl -X PATCH https://app.klara-ai.com/api/external/applications/550e8400-e29b-41d4-a716-446655440000 \
  -H "Authorization: Bearer klara_abc123def456.your-secret-here" \
  -H "Content-Type: application/json" \
  -d '{
    "fields": {
      "company_name": "Acme Financial Ltd",
      "company_number": "12345678",
      "company_country": "GB"
    }
  }'

const applicationId = '550e8400-e29b-41d4-a716-446655440000';

const response = await fetch(
  `https://app.klara-ai.com/api/external/applications/${applicationId}`,
  {
    method: 'PATCH',
    headers: {
      'Authorization': 'Bearer klara_abc123def456.your-secret-here',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      fields: {
        company_name: 'Acme Financial Ltd',
        company_number: '12345678',
        company_country: 'GB'
      }
    })
  }
);

const data = await response.json();

import requests

application_id = '550e8400-e29b-41d4-a716-446655440000'

response = requests.patch(
    f'https://app.klara-ai.com/api/external/applications/{application_id}',
    headers={
        'Authorization': 'Bearer klara_abc123def456.your-secret-here',
        'Content-Type': 'application/json'
    },
    json={
        'fields': {
            'company_name': 'Acme Financial Ltd',
            'company_number': '12345678',
            'company_country': 'GB'
        }
    }
)

data = response.json()

Response:

{
  "success": true,
  "application_id": "550e8400-e29b-41d4-a716-446655440000",
  "updated_fields": ["company_name", "company_number", "company_country"]
}

Errors

{
  "error": "Invalid request body. Only \"fields\" can be updated via this endpoint.",
  "details": {
    "_errors": ["Unrecognized key(s) in object: 'people'"]
  }
}

{
  "error": "Unknown or non-writable field ids: not_a_field"
}

{
  "error": "Invalid field values — industry: Please select a valid option"
}

{
  "error": "Cannot update application in submitted status"
}

{
  "error": "Invalid API key"
}

{
  "error": "Application not found"
}

Error	Cause
`Invalid JSON body`	Request body is not valid JSON
`Invalid request body. Only "fields" can be updated via this endpoint.`	Body contains top-level keys other than `fields` (e.g., `people`, `ownership`), or `fields` is missing or empty
`Unknown or non-writable field ids: ...`	One or more keys in `fields` are not defined in the application’s configuration, or are document-type, person-scoped, or confirmation fields
`Invalid field values — ...`	One or more values failed validation (off-list option, wrong shape, or a format rule) — the message lists each failing field
`Cannot update application in {status} status`	The application has been submitted — data is frozen
`Invalid API key`	API key is invalid, expired, or inactive
`API key missing required scopes`	API key does not have the `applications:write` scope
`Application not found`	The application does not exist or belongs to a different organization

Overview

Applications

Reference

Update Application

Authentication

Path parameters

Request body

Value validation

Behavior

Response

Examples

Pre-filling company details

Errors

​Authentication

​Path parameters

​Request body

​Value validation

​Behavior

​Response

​Examples

​Pre-filling company details

​Errors

Authentication

Path parameters

Request body

Value validation

Behavior

Response

Examples

Pre-filling company details

Errors