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

# Update JSON Error Response Template

> Updates JSON error response template for an API proxy. JSON error template defines the format of error responses for REST/JSON APIs.

## Endpoint

```
PATCH /apiops/projects/{projectName}/apiProxies/{apiProxyName}/settings/json-error-template/
```

## Authentication

Requires a Personal API Access Token.

### Header

```
Authorization: Bearer YOUR_TOKEN
```

## Request

### Headers

| Header        | Value            | Required |
| ------------- | ---------------- | -------- |
| Authorization | Bearer {token}   | Yes      |
| Content-Type  | application/json | Yes      |

### Path Parameters

| Parameter    | Type   | Required | Description    |
| ------------ | ------ | -------- | -------------- |
| projectName  | string | Yes      | Project name   |
| apiProxyName | string | Yes      | API Proxy name |

### Request Body

#### Full JSON Body Example

```json theme={null}
{
  "jsonErrorResponseTemplate": {
    "jsonErrorResponseTemplateActive": true,
    "jsonValue": "{\n  \"fault\": {\n    \"correlationId\": \"#CORRELATIONID#\",\n    \"faultCode\": \"#FAULTCODE#\",\n    \"faultString\": \"#FAULTMESSAGE#\",\n    \"faultStatusCode\": \"#FAULTSTATUSCODE#\",\n    \"responseFromApi\": \"#RESPONSEFROMAPI#\"\n  }\n}",
    "contentType": "application/json;charset=UTF-8",
    "permitSpecialChars": false
  },
  "deploy": false,
  "deployTargetEnvironmentNameList": []
}
```

#### Request Body Fields

| Field                           | Type           | Required | Default | Description                                                        |
| ------------------------------- | -------------- | -------- | ------- | ------------------------------------------------------------------ |
| jsonErrorResponseTemplate       | object         | Yes      | -       | JSON error template object (see fields below)                      |
| deploy                          | boolean        | No       | false   | If true, deploy the API proxy after saving changes                 |
| deployTargetEnvironmentNameList | array\[string] | No       | -       | List of environment names to deploy to (required when deploy=true) |

#### jsonErrorResponseTemplate Fields

| Field                           | Type    | Required | Default                        | Description                           |
| ------------------------------- | ------- | -------- | ------------------------------ | ------------------------------------- |
| jsonErrorResponseTemplateActive | boolean | No       | false                          | Enable/disable JSON error template    |
| jsonValue                       | string  | No       | -                              | JSON error response template          |
| contentType                     | string  | No       | application/json;charset=UTF-8 | Content type for error response       |
| permitSpecialChars              | boolean | No       | false                          | Permit special characters in template |

### Template Variables

The JSON template can use the following variables (replaced at runtime):

* `#CORRELATIONID#` - Request correlation ID
* `#FAULTCODE#` - Error fault code
* `#FAULTMESSAGE#` - Error fault message
* `#FAULTSTATUSCODE#` - HTTP status code
* `#RESPONSEFROMAPI#` - Response from backend API (if available)

### Default Template

```json theme={null}
{
  "fault": {
    "correlationId": "#CORRELATIONID#",
    "faultCode": "#FAULTCODE#",
    "faultString": "#FAULTMESSAGE#",
    "faultStatusCode": "#FAULTSTATUSCODE#",
    "responseFromApi": "#RESPONSEFROMAPI#"
  }
}
```

**Note:** All fields are optional. Only provided fields are updated.

## Response

### Success Response (200 OK)

```json theme={null}
{
  "success": true
}
```

#### Response Fields

| Field   | Type    | Description                             |
| ------- | ------- | --------------------------------------- |
| success | boolean | Indicates if the request was successful |

When `deploy=true` is specified:

```json theme={null}
{
  "success": true,
  "deploymentResult": {
    "success": true,
    "deploymentResults": [
      {
        "environmentName": "production",
        "success": true,
        "message": "Deployment successful"
      }
    ]
  }
}
```

| Field                              | Type    | Description                                  |
| ---------------------------------- | ------- | -------------------------------------------- |
| deploymentResult                   | object  | Deployment result (present when deploy=true) |
| deploymentResult.success           | boolean | Overall deployment success status            |
| deploymentResult.deploymentResults | array   | Per-environment deployment results           |

### Error Response (400 Bad Request)

```json theme={null}
{
  "error": "bad_request",
  "error_description": "Invalid JSON template"
}
```

### Error Response (401 Unauthorized)

```json theme={null}
{
  "error": "unauthorized_client",
  "error_description": "Invalid token"
}
```

### Error Response (404 Not Found)

```json theme={null}
{
  "error": "not_found",
  "error_description": "ApiProxy (name: MyAPI) was not found!"
}
```

## cURL Example

### Example 1: Enable JSON Error Template

```bash theme={null}
curl -X PATCH \
  "https://demo.apinizer.com/apiops/projects/MyProject/apiProxies/MyAPI/settings/json-error-template/" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonErrorResponseTemplate": {
      "jsonErrorResponseTemplateActive": true,
      "jsonValue": "{\n  \"fault\": {\n    \"correlationId\": \"#CORRELATIONID#\",\n    \"faultCode\": \"#FAULTCODE#\",\n    \"faultString\": \"#FAULTMESSAGE#\",\n    \"faultStatusCode\": \"#FAULTSTATUSCODE#\"\n  }\n}",
      "contentType": "application/json;charset=UTF-8"
    }
  }'
```

### Example 2: Custom JSON Error Template

```bash theme={null}
curl -X PATCH \
  "https://demo.apinizer.com/apiops/projects/MyProject/apiProxies/MyAPI/settings/json-error-template/" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonErrorResponseTemplate": {
      "jsonErrorResponseTemplateActive": true,
      "jsonValue": "{\n  \"error\": {\n    \"id\": \"#CORRELATIONID#\",\n    \"code\": \"#FAULTCODE#\",\n    \"message\": \"#FAULTMESSAGE#\",\n    \"status\": #FAULTSTATUSCODE#\n  }\n}",
      "contentType": "application/json;charset=UTF-8",
      "permitSpecialChars": true
    }
  }'
```

### Example 3: Save and Deploy

```bash theme={null}
curl -X PATCH \
  "https://demo.apinizer.com/apiops/projects/MyProject/apiProxies/MyAPI/settings/json-error-template/" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonErrorResponseTemplate": {
      "jsonErrorResponseTemplateActive": true,
      "jsonValue": "{\n  \"fault\": {\n    \"correlationId\": \"#CORRELATIONID#\",\n    \"faultCode\": \"#FAULTCODE#\",\n    \"faultString\": \"#FAULTMESSAGE#\",\n    \"faultStatusCode\": \"#FAULTSTATUSCODE#\"\n  }\n}",
      "contentType": "application/json;charset=UTF-8"
    },
    "deploy": true,
    "deployTargetEnvironmentNameList": ["production"]
  }'
```

## Notes and Warnings

* **Template Variables**: Use `#VARIABLE#` syntax for runtime replacement
* **JSON Format**: Template must be valid JSON (use escaped quotes in string)
* **Content Type**: Default is `application/json;charset=UTF-8`
* **Special Characters**: When `permitSpecialChars=true`, special characters are not escaped
* **Active Flag**: Set `jsonErrorResponseTemplateActive=true` to enable template
* **REST APIs**: Primarily used for REST/JSON APIs
* **Deploy**: When `deploy=true`, the API proxy is automatically deployed to the specified environments after saving

## Permissions

User must have **`API_MANAGEMENT` + `MANAGE`** permission in the project.

## Related Documentation

* [Update XML Error Template](/api-reference/api-proxies/settings/update-xml-error-template) - Update XML error template
* [Get API Proxy](/api-reference/api-proxies/crud/get-api-proxy) - Get API proxy details