Update external API call

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

# Update external API call

> Update one external API call step.

Updates one external API call record. The wire-format object is still called [`Data Step`](/en/api-reference/actions-and-attributes#data-step-object). All fields are optional; send only what you want to change.

<Note>
  Sensitive header and body values are preserved when you echo the masked `"********"` back. Send a new string to replace a secret. See [Sensitive values and masking](/en/api-reference/actions-and-attributes#sensitive-values-and-masking).
</Note>

## Headers

<ParamField header="Authorization" type="string" required>
  Bearer token containing your Fini workspace API key. Format: `Bearer fini_...` The key needs `write` scope.
</ParamField>

<ParamField header="Content-Type" type="string" required>
  `application/json`
</ParamField>

## Path parameters

<ParamField path="id" type="string" required>
  External API call step ID to update.
</ParamField>

## Body parameters

<ParamField body="name" type="string">
  Updated step name.
</ParamField>

<ParamField body="requestUrl" type="string">
  Updated request URL. Supports `${fieldName}` interpolation from inputs and `${stepId.responseMappingKey}` interpolation from earlier external API calls. `{{placeholder}}` syntax is not supported.
</ParamField>

<ParamField body="requestMethod" type="string">
  Updated HTTP verb.
</ParamField>

<ParamField body="requestHeaders" type="object">
  Updated request headers. Echo the masked value back to keep a stored secret.
</ParamField>

<ParamField body="requestBody" type="object">
  Updated request body, with the same masking behavior as headers.
</ParamField>

<ParamField body="responseMapping" type="ResponseMapping">
  Updated output mapping. See [ResponseMapping](/en/api-reference/actions-and-attributes#responsemapping-object).
</ParamField>

## Response

Returns the updated [`Data Step`](/en/api-reference/actions-and-attributes#data-step-object) with sensitive values masked.

<RequestExample>
  ~~~bash cURL theme={null}
  curl --request PATCH \
    --url 'https://api-prod.usefini.com/v2/api-function-configs/4f5ef695-d03b-4d56-8fef-7f2bd5c17ef3/public' \
    --header 'Authorization: Bearer fini_your_api_key' \
    --header 'Content-Type: application/json' \
    --data '{
    "name": "Refund policy",
    "requestUrl": "https://help.example.com/refunds",
    "requestMethod": "GET",
    "requestHeaders": {
      "name": "Example",
      "value": "message"
    },
    "requestBody": {
      "name": "Example",
      "value": "message"
    },
    "responseMapping": "4f5ef695-d03b-4d56-8fef-7f2bd5c17ef3"
  }'
  ~~~

  ~~~javascript Node.js theme={null}
  const response = await fetch('https://api-prod.usefini.com/v2/api-function-configs/4f5ef695-d03b-4d56-8fef-7f2bd5c17ef3/public', {
    method: 'PATCH',
    headers: {
      Authorization: 'Bearer fini_your_api_key',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
    'name': 'Refund policy',
    'requestUrl': 'https://help.example.com/refunds',
    'requestMethod': 'GET',
    'requestHeaders': {
      'name': 'Example',
      'value': 'message'
    },
    'requestBody': {
      'name': 'Example',
      'value': 'message'
    },
    'responseMapping': '4f5ef695-d03b-4d56-8fef-7f2bd5c17ef3'
  }
    )
  });

  const data = await response.json();
  ~~~

  ~~~python Python theme={null}
  import requests

  response = requests.patch(
      "https://api-prod.usefini.com/v2/api-function-configs/4f5ef695-d03b-4d56-8fef-7f2bd5c17ef3/public",
      headers={"Authorization": "Bearer fini_your_api_key", "Content-Type": "application/json"},
      json={
      "name": "Refund policy",
      "requestUrl": "https://help.example.com/refunds",
      "requestMethod": "GET",
      "requestHeaders": {
          "name": "Example",
          "value": "message"
      },
      "requestBody": {
          "name": "Example",
          "value": "message"
      },
      "responseMapping": "4f5ef695-d03b-4d56-8fef-7f2bd5c17ef3"
  },
  )

  data = response.json()
  ~~~
</RequestExample>

<ResponseExample>
  ~~~json 200 OK theme={null}
  {
    "id": "4f5ef695-d03b-4d56-8fef-7f2bd5c17ef3",
    "name": "Lookup customer",
    "method": "GET",
    "url": "https://api.example.com/customers/{customerId}",
    "headers": {
      "Authorization": "Bearer ${apiToken}"
    },
    "saveFromResponse": {
      "plan": "customer.plan",
      "status": "customer.status"
    },
    "createdAt": "2026-07-28T08:55:32.000Z",
    "updatedAt": "2026-07-28T09:10:18.000Z"
  }
  ~~~
</ResponseExample>

## Errors

<AccordionGroup>
  <Accordion title="400 Bad Request" icon="circle-exclamation">
    The body is malformed.
  </Accordion>

  <Accordion title="401 Unauthorized" icon="lock">
    The API key is missing, malformed, revoked, or invalid.
  </Accordion>

  <Accordion title="403 Forbidden" icon="shield-halved">
    The API key does not include the `write` scope required for this route.
  </Accordion>

  <Accordion title="500 Internal Server Error" icon="triangle-exclamation">
    Fini failed while updating the Data Step, for example when the ID does not exist.
  </Accordion>
</AccordionGroup>


## Related topics

- [Overview](/en/api-reference/actions-and-attributes.md)
- [Test external API call](/en/api-reference/test-data-step.md)
- [Get external API call](/en/api-reference/get-data-step.md)


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