For AI agents: a documentation index is available at the root level at /llms.txt and /llms-full.txt. Append /llms.txt to any URL for a page-level index, or .md for the markdown version of any page.
Book a demoLog inStart for free
  • Overview
    • Introduction
    • How it works
    • Quickstart
    • Customer showcase
  • Working with SDKs
    • Project structure
    • Adding custom code
    • Migrating to Replay
    • Capabilities
  • Generators
      • Generating an SDK
      • Publishing to PyPI
      • Configuration
      • Adding custom code
      • Dynamic authentication
      • aiohttp support
      • Changelog
      • Customer showcase
  • Reference
    • generators.yml
Checking status...
SOC2Soc 2 Type II
© 2026 Fern • Birch Solutions, Inc., a Postman company

Documentation

SDKsDocsAsk FernCLI Reference

API Definitions

OpenAPIAsyncAPIOpenRPCgRPC

Resources

BlogSupportPricing

Company

Brand KitPrivacy PolicyTerms of Service
LogoLogo
Book a demoLog inStart for free
GeneratorsPython

Changelog

April 2, 2026
April 2, 2026

5.3.0

(feat): Add aiohttp auto-detection for async clients. When the httpx-aiohttp package is installed, the async client automatically uses HttpxAiohttpClient instead of the default httpx.AsyncClient. Adds optional aiohttp and httpx-aiohttp dependencies exposed via a [aiohttp] pip extra, along with DefaultAioHttpClient and DefaultAsyncHttpxClient convenience classes in _default_clients.py.

5.2.2

(fix): Fix extra_dependencies override behavior so user-specified dependency versions reliably take precedence over bundled generator defaults. Previously, bundled dependencies (e.g., pydantic, typing_extensions) added during generation would overwrite customer version pins from extra_dependencies. User overrides are now protected from being overwritten by internal dependency additions.

Was this page helpful?
Edit this page
Previous

April 3, 2026

Next

March 31, 2026