# operation-id-unique

Source: https://apigenie.pl/docs/linter/openapi/rules/operation-id-unique

This rule checks whether operations defined in an OpenAPI schema have unique
IDs.

## Rule Details

Duplicate operation ID make it difficult to reason about their purpose, as
well as about.

The `operation-id-unique` rule checks IDs of operations defined in an OpenAPI
schema and warn if duplicates found. Empty operation IDs do not count as
duplicates.

## Configuration

The optional `nonPathNaming` value controls generated webhook and component
path-item names: `scope-prefix` (default), `path-like`, or `scope-suffix`.

## Examples

**Good**. It is immediately visible what each operation does.

```yaml
paths:
  /users:
    get:
      operationId: getUsers
      responses:
        "200":
          description: A list of users.
  /users/{id}:
    get:
      operationId: getUserById
      responses:
        "200":
          description: A single user.
```

**Bad**. Two operations have identical IDs, which makes it difficult to decide
which one to use in each case.

```yaml
paths:
    /downloads:
        patch:
            # changes the status to 'cancelled'
            operationId: cancelDownload
            ...
        delete:
            operationId: cancelDownload
            ...
```

## When Not to Use It

We recommend to always enable this rule.

## Automatic fixes

When invoked with `--fix`, this rule keeps the first occurrence and regenerates
later duplicates using the same deterministic generator and collision policy as
`operation-id-defined`.

## Compatibility

This rule is compatible with all OpenAPI 3.x versions.