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 Packagist
      • Configuration
      • Adding custom code
      • 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
GeneratorsPHP

Changelog

December 1, 2025
December 1, 2025

1.24.0

(feat): Retries now check Retry-After and X-RateLimit-Reset response headers before defaulting to exponential backoff. Added jitter to retry delays and capped maximum retry delay at 60 seconds.

1.23.11

(chore): Remove verbose debug logs for endpoint snippet processing and generation counts.

1.23.10

(fix): Fix union deserialization to catch Throwable instead of Exception. Previously, when deserializing union types, TypeError exceptions thrown during property assignment (e.g., assigning null to a non-nullable int property) were not caught, preventing the union from trying alternative types. This fix ensures that all errors during union type deserialization are caught, allowing proper fallthrough to the next union variant.

1.23.9

(fix): Fix JsonException “No constructor found” for empty object types. Previously, object types with no properties would not generate a constructor, causing JSON deserialization to fail. Now all JsonSerializableType subclasses generate a constructor with the expected array $values parameter signature.

1.23.8

(fix): Normalize UTC datetime serialization to use Z suffix instead of +00:00. The JsonSerializer now converts 2023-01-01T12:34:56+00:00 to 2023-01-01T12:34:56Z for UTC times while preserving RFC3339 format for non-UTC timezones. Query parameters and headers now use JsonSerializer::serializeDateTime() for consistent datetime formatting. Test templates updated to match the new behavior.

Was this page helpful?
Edit this page
Previous

December 2, 2025

Next

November 27, 2025