SDK Method Names (OpenRPC) | Fern Documentation

By default, Fern generates SDK method names based on your OpenRPC method names. You can override this behavior using the x-fern-sdk-method-name extension.

Customize method names

Use x-fern-sdk-method-name to specify custom method names for your JSON-RPC methods:

openrpc.yml

methods:
  - name: user.getById
    summary: Get user by ID
    x-fern-sdk-method-name: getUser
    params:
      - name: id
        schema:
          type: string
        required: true
    result:
      name: user
      schema:
        $ref: '#/components/schemas/User'
  - name: order.createNew
    summary: Create a new order
    x-fern-sdk-method-name: create
    params:
      - name: orderData
        schema:
          $ref: '#/components/schemas/CreateOrderRequest'
        required: true
    result:
      name: order
      schema:
        $ref: '#/components/schemas/Order'

This will generate SDK methods like:

// Instead of client.user.getById()
const user = await client.user.getUser({ id: "user_123" });
// Instead of client.order.createNew()
const order = await client.order.create({ orderData: {...} });

Method naming conventions

Follow these conventions when naming SDK methods:

CRUD operations

Use standard CRUD naming:

openrpc.yml

methods:
  - name: user.createUser
    summary: Create a new user
    x-fern-sdk-method-name: create
    # Generates: client.user.create()
    
  - name: user.getUserById
    summary: Get user by ID
    x-fern-sdk-method-name: get
    # Generates: client.user.get()
    
  - name: user.updateUser
    summary: Update user information
    x-fern-sdk-method-name: update
    # Generates: client.user.update()
    
  - name: user.deleteUser
    summary: Delete a user
    x-fern-sdk-method-name: delete
    # Generates: client.user.delete()

List operations

Use descriptive names for list operations:

openrpc.yml

methods:
  - name: user.getAllUsers
    summary: Get all users
    x-fern-sdk-method-name: list
    # Generates: client.user.list()
    
  - name: user.searchUsers
    summary: Search for users
    x-fern-sdk-method-name: search
    # Generates: client.user.search()
    
  - name: order.getUserOrders
    summary: Get orders for a user
    x-fern-sdk-method-name: listByUser
    # Generates: client.order.listByUser()

Action operations

Use action-oriented names:

openrpc.yml

methods:
  - name: email.sendNotification
    summary: Send email notification
    x-fern-sdk-method-name: send
    # Generates: client.email.send()
    
  - name: payment.processPayment
    summary: Process a payment
    x-fern-sdk-method-name: process
    # Generates: client.payment.process()
    
  - name: cache.invalidateCache
    summary: Invalidate cache entries
    x-fern-sdk-method-name: invalidate
    # Generates: client.cache.invalidate()

Language-specific method names

You can specify different method names for different programming languages:

openrpc.yml

methods:
  - name: user.getUserPreferences
    summary: Get user preferences
    x-fern-sdk-method-name:
      python: get_preferences
      typescript: getPreferences
      go: GetPreferences
      java: getPreferences
      csharp: GetPreferences
    params:
      - name: userId
        schema:
          type: string
        required: true
    result:
      name: preferences
      schema:
        $ref: '#/components/schemas/UserPreferences'

Namespaced method names

For methods with namespace prefixes, customize the final method name:

openrpc.yml

methods:
  - name: analytics.track.pageView
    summary: Track page view event
    x-fern-sdk-method-name: trackPageView
    params:
      - name: eventData
        schema:
          $ref: '#/components/schemas/PageViewEvent'
        required: true
  - name: analytics.track.conversion
    summary: Track conversion event
    x-fern-sdk-method-name: trackConversion
    params:
      - name: eventData
        schema:
          $ref: '#/components/schemas/ConversionEvent'
        required: true

Generates:

await client.analytics.trackPageView({ eventData: {...} });
await client.analytics.trackConversion({ eventData: {...} });

Notification method names

For notification methods (one-way calls), use appropriate naming:

openrpc.yml

methods:
  - name: log.recordError
    summary: Record an error event
    x-fern-sdk-method-name: logError
    params:
      - name: errorData
        schema:
          $ref: '#/components/schemas/ErrorData'
        required: true
    # No result - this is a notification
  - name: metrics.incrementCounter
    summary: Increment a metric counter
    x-fern-sdk-method-name: increment
    params:
      - name: metric
        schema:
          type: string
        required: true
      - name: value
        schema:
          type: number
          default: 1
    # No result - this is a notification

Async method naming

For methods that return promises or futures, consider async naming:

openrpc.yml

methods:
  - name: report.generateReport
    summary: Generate a report (long-running)
    x-fern-sdk-method-name: generateAsync
    params:
      - name: reportConfig
        schema:
          $ref: '#/components/schemas/ReportConfig'
        required: true
    result:
      name: jobId
      schema:
        type: string
        description: Job ID for tracking report generation

This ensures method names follow the conventions of each target language while maintaining clear and intuitive APIs for developers.