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# Customize SDK method names

> Use `x-fern-sdk-method-name` and `x-fern-sdk-group-name` to finetune SDK naming.

Use the `x-fern-sdk-group-name` and `x-fern-sdk-method-name` extensions to control how endpoints are organized in your [SDKs](/learn/sdks/overview/introduction) and [CLIs](/learn/cli-generator/get-started/openapi-extensions).

#### Fern automatically parses \`operationId\`

If no extensions are present, Fern uses your operation ID to generate SDK method names. Format operation IDs as `{tag_name}_{operation_name}` (example: `users_get`) to automatically generate methods like `users.get()`. If the operation ID doesn't start with a tag, Fern uses it directly as the method name.

In the example below, Fern will generate a
method called `client.users.create()` for the `POST /users` endpoint.

**`openapi.yml`**

```yaml title="openapi.yml" {4-5}
paths:
  /users:
    post:
      x-fern-sdk-group-name: users
      x-fern-sdk-method-name: create
```

### Top level methods

If you omit the `x-fern-sdk-group-name` extension, the generated SDK method
will live at the root of the client rather than nested under a resource group.
In the example below, Fern will generate a method called `client.send()`:

**`openapi.yml`**

```yaml title="openapi.yml" {4}
paths:
  /send:
    post:
      x-fern-sdk-method-name: send
```

### Multiple levels of nesting

See how merge.dev uses nested groups [here](https://github.com/merge-api/merge-node-client?tab=readme-ov-file#create-link-token).

If you add more than one `x-fern-sdk-group-name` extension, then the generated SDK will nest group names.
The generated SDK method preserves the order of group names.

In the example below, Fern will generate a method called `client.users.notifications.send()`:

**`openapi.yml`**

```yaml title="openapi.yml"
paths:
  /users/notifications:
    post:
      x-fern-sdk-group-name:
        - users
        - notifications
      x-fern-sdk-method-name: send
```

### Ignore tags

Without extensions, Fern derives SDK group names from operation-level `tags`. Set [`ignore-tags`](/learn/sdks/reference/generators-yml#settingsignore-tags) in `generators.yml` to ignore tags when determining SDK structure: endpoints fall back to the root package (or their `namespace`), and method names are derived from each operation's `operationId`.

**`generators.yml`**

```yaml title="generators.yml" {5}
api:
  specs:
    - openapi: ./openapi.yml
      settings:
        ignore-tags: true
```

`x-fern-sdk-group-name` and `x-fern-sdk-method-name` still take precedence, so you can group individual endpoints while ignoring tags elsewhere. Enabling `ignore-tags` avoids editing the spec or maintaining overlays when tags would otherwise produce awkward sub-clients, such as a `ConversationsV2Configuration` tag becoming a `conversations_v2_configuration` sub-client.

> Use `x-fern-sdk-method-name` and `x-fern-sdk-group-name` to finetune SDK naming.