# operation-2xx-response

Ensures that every operation in your API document has at least one successful (200-299) HTTP response defined.

| OAS | Compatibility |
| --- | --- |
| 2.0 | ✅ |
| 3.0 | ✅ |
| 3.1 | ✅ |

## API design principles

One of the main goals of your API description (and your API documentation) is to help consumers understand how your API behaves and what to expect when working with it.

When designing your APIs, every operation should have a successful HTTP response.
If it doesn't, what is the purpose of the operation?
Even if there is no response content (204), it can still return a successful response with no content.
You can greatly improve the developer and user experience of your APIs by making it a standard to provide this information.

If you describe a WebSocket connection in OpenAPI, its operation usually has only a `101 Switching Protocols` response, and this rule reports it.
This outcome is expected: 101 is an informational response, not a successful one.
OpenAPI can't describe the messages sent over a WebSocket connection, so describe WebSocket APIs with AsyncAPI instead.

## Configuration

| Option | Type | Description |
| --- | --- | --- |
| severity | string | Possible values: `off`, `warn`, `error`. Default `warn` (in `recommended` configuration). |
| validateWebhooks | boolean | Determines if responses inside webhooks are validated. Default `false`. |

An example configuration:

```yaml
rules:
  operation-2xx-response: error
```

The following example enables validation of responses inside webhooks:

```yaml
rules:
  operation-2xx-response:
    severity: error
    validateWebhooks: true
```

## Examples

Given this configuration:

```yaml
rules:
  operation-2xx-response: error
```

Example of **incorrect** operation response:

```yaml
post:
  responses:
    '400':
      $ref: ../components/responses/Problem.yaml
```

Example of **correct** operation response:

```yaml
post:
  responses:
    '200':
      $ref: ../components/responses/Success.yaml
    '400':
      $ref: ../components/responses/Problem.yaml
```

## Related rules

- [operation-4xx-response](/docs/cli/v1/rules/oas/operation-4xx-response)

## Resources

- [Rule source](https://github.com/Redocly/redocly-cli/blob/main/packages/core/src/rules/common/operation-2xx-response.ts)
- [Responses map docs](https://redocly.com/docs/openapi-visual-reference/responses/)