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ReferenceRelease Notes

Release notes

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This page is statically generated from the Github releases , and may sometimes be slightly out of date.

27 May 2026 (v0.24.0)

This is a relatively small release, mostly focused on a few notable bug fixes. Also contains some improvements to generated zod-v4 schemas.

Axios Client Default Timeout (potentially breaking)

  • Previously this was ignored (since forever apparently :grimacing:)
  • This meant that unless you passed an axios instance that itself had a default timeout configured, the axios default of no timeout was used
  • Now the defaultTimeout value will be respected, overriding that of the passed axios instance
  • https://github.com/mnahkies/openapi-code-generator/pull/463 

This may cause some request timeouts, if you previously had too low of a timeout. It may prevent seeming “hung” requests under certain network conditions that you may have previously experienced.

Browser compatibility for fetch / axios runtimes

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.23.0…v0.24.0 

9 May 2026 (v0.23.0)

This is an unusually large release, containing major architectural improvements, enhanced query parameter handling, and support for binary data.

It also contains several breaking changes to improve the internal domain model and consistency of the generated code, that will unblock further enhancements.

  • Migrated to tsdown for bundling, providing both ESM and CJS variants of runtime packages #452, #456

  • This shouldn’t be a breaking change, but its significant enough to be aware of it

  • Runtime & Response Processing

  • Renamed Response to Res in runtime packages to avoid conflicts with the global DOM Response object #405

  • Removed deprecated exports that are no longer used in regenerated code #406

  • Migration: Regenerate your code using the latest CLI and update any manual imports from runtime packages referencing Response

  • Schema & Type Naming

  • Refactored “virtual schema” generation. This improves support for OAS 3.1+ but results in changed names for some anonymous types #398

  • Some indirection has been removed e.g., types that just pointed to other types are now unwrapped

  • Migration: You may need to update manual type references in your project if they were using generated anonymous names

  • Query Parameter Serialization

  • Dropped qs dependency in favor of internal logic that strictly respects OpenAPI style and explode modifiers #381

  • koa v3 and @koa/router@v15 now the minimum requirement #442

  • Dropped broken readOnly modifier support #409

  • Binary Data Support: Added support for application/octet-stream in both request and response bodies #359

  • Improved Records: Better handling of additionalProperties, emitting Record<string, T> or any as appropriate #408, #402

  • Middleware: Added support for mounting middleware on individual routers via an optional parameter to createRouter #442

  • Improved handling of allOf, anyOf, and oneOf #410

  • Fixed missing types when enum is defined without an explicit type #407

  • Fixed handling of boolean values for exclusiveMaximum and exclusiveMinimum #386

  • Fixed tsconfig loading when compilerOptions is missing #382

  • The logger now correctly respects NO_COLOR and similar environment variables #414

  • Client Fetch: Fixed type narrowing issues with default response types in the fetch runtime #443

  • Koa Server: Fixed overlapping route matching by no longer calling next() after a route handler is executed #442

  • Dependencies: Extensive dependency refreshes, including migrations to Angular v21, Next.js v16.1, and TypeScript v6

  • Testing: Significant expansion of the test suite, including new unit tests for schema normalization and type building #387, #389, #412

  • CI/CD: Dropped Node v20 from CI, improved integration test performance using tsgo #451, and enabled publint and attw for better package compatibility #454

  • Refactors: Major internal reorganization of the Input class and schema providers to simplify the dependency graph and improve testability #388, #416, #420

  • Introduced code sharing between the runtime packages #401

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.22.0…v0.23.0 

2 Nov 2025 (v0.22.0)

This is a pretty significant release, with two larger features:

  • Support for Zod V4, whilst retaining support for Zod V3
  • Support for projects using ESM, and use import type where possible

Aside from this, we’ve made efforts to improve supply chain security :lock:

  • Adopted trusted publishers / Github Actions to publish releases
  • Added a minimum release age of 7 days for dependencies
  • Removed unmaintained dependency

As well as improving the CI setup to run integration and e2e tests across more variants to reduce risk of regressions :test_tube:

  • --schema-builder defaults to zod-v4
  • --schema-builder no longer accepts zod, you must specify either zod-v3 or zod-v4 as required for your project

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.21.1…v0.22.0 

26 Oct 2025 (v0.22.0-alpha.0)

This is a pretty significant release, with two larger features:

  • Support for Zod V4, whilst retaining support for Zod V3
  • Support for projects using ESM, and use import type where possible

As such it’s being made available as an alpha release for further regression testing: https://www.npmjs.com/package/@nahkies/openapi-code-generator/v/0.22.0-alpha.0 

Aside from this, we’ve made efforts to improve supply chain security :lock:

  • Adopted trusted publishers / Github Actions to publish releases
  • Added a minimum release age of 7 days for dependencies
  • Removed unmaintained dependency

As well as improving the CI setup to run integration and e2e tests across more variants to reduce risk of regressions.

  • --schema-builder defaults to zod-v4
  • --schema-builder no longer accepts zod, you must specify either zod-v3 or zod-v4 as required for your project

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.21.1…v0.22.0-alpha.0 

13 Aug 2025 (v0.21.1)

Bug fix release for #360 / #361 - previously nullable string schemas with a default of null would instead default to the string "null" - thanks @geuben!

Bug Fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.21.0…v0.21.1 

26 Jul 2025 (v0.21.0)

This is a bigger than normal release, and contains a number of potentially breaking changes - however in general, these are making it clearer when the code generator doesn’t support something properly (eg: it was probably already broken).

The primary changes are:

  • Unsupported Content-Type will now generate never as their typescript type
  • HTML form data submissions (application/x-www-form-urlencoded) are now supported
  • text/plain request bodies are also now supported
  • The CLI will auto-detect your formatter (biome/prettier) config and then use that config / formatter during code generation
  • Boolean schemas can now include an enum to restrict them to literal true or false
  • Server urls now allow “required” variables/placeholders

As well as several minor bug fixes, and maintenance chores. Most notably switching to pnpm which will hopefully help prevent issues with missing dependencies or misaligned peer dependencies in future.

Features

Bug Fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.20.1…v0.21.0 

31 May 2025 (v0.20.1)

This is a bug fix release that fixes some edge cases and adds compatibility with NodeJS v24.

Bug fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.20.0…v0.20.1 

5 May 2025 (v0.20.0)

The main feature in this release is a new typescript-express server generation template. Its very similar in function to the typescript-koa template, but allows use of the express middleware ecosystem.

See the documentation here: https://openapi-code-generator.nahkies.co.nz/guides/server-templates/typescript-express 

There was also some improvements of the availability of “escape hatches”, namely you can now return a SkipResponse symbol to bypass the normal response validation and sending, allowing your handler full control over this.

Features

Bug Fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.19.2…v0.20.0 

19 Apr 2025 (v0.19.2)

Another attempt to solve running by npx

Bug fixes

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.19.1…v0.19.2 

18 Apr 2025 (v0.19.1)

Hopefully resolves being able to run via npx without issues.

Bug fixes

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.19.0…v0.19.1 

18 Apr 2025 (v0.19.0)

The headline feature, and potentially breaking change, is safer enum evolution. You can read more about it on the documentation site here: https://openapi-code-generator.nahkies.co.nz/guides/concepts/enums 

Otherwise included some minor bug fixes to joi schema generation, and misc testing improvements.

Features

Bug fixes

Docs

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.18.0…v0.19.0 

22 Dec 2024 (v0.18.0)

Primarily a bug-fix release focusing on improving client SDK runtime validation.

POTENTIALLY BREAKING CHANGES

  • Users of joi validation must change the dependency from @hapi/joi to joi
  • Unused Res and StatusCode types removed from typescript-axios-runtime package
  • TypedFetchResponse removed from typescript-fetch-runtime package, use exported type Res instead if needed

Bug fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.17.0…v0.18.0 

11 Dec 2024 (v0.17.0)

The main change is that server overrides at the path / operation level will now be respected and create an additional positional parameter for these methods when generating clients (closes #266).

There was also a fix for client generation with --enable-runtime-response-validation, when the typescript project has exactOptionalPropertyTypes: true in its tsconfig.json

Additionally defaultHeaders is now optional in client configuration, and the HTTP head verb is now supported. The documentation  got a few new pages including a roadmap, and some general tips on usage.

BREAKING CHANGES

  • New positional parameter on methods where server overrides are included in the specification
  • Unique export names for Angular services now suffixed with Service

Features

Bug Fixes

Docs

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.16.0…v0.17.0 

2 Nov 2024 (v0.16.0)

Client class exports will now be given unique names generated from the input specifications info.title field. This can additionally be overridden through a new cli arg --override-specification-title.

The previous generic exports are kept for backwards compatibility.

POTENTIALLY BREAKING: Filenames generated from tags or route prefixes will now follow kebab-case naming convention by default. This can be customized to other conventions like camel-case, etc using --filename-convention

Features

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.15.0…v0.16.0 

27 Oct 2024 (v0.15.0)

It’s now possible to change the construct used for the “implementation” symbol between being a type, interface or abstract class using the new option --ts-server-implementation-method. This is particularly useful if using a dependency injection library that requires abstract class as part of its wiring approach.

Additionally, when splitting the generated files by first-tag / first-slug (using --grouping-strategy), the tag/slug will now be added to the exported symbol names, eg: createRouter -> createMyTagRouter and Implementation -> MyTagImplementation. This can reduce the need to alias imports manually.

The generic Implementation / createRouter exports have be retained to keep this backwards compatible.

Features

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.14.0…v0.15.0 

12 Oct 2024 (v0.14.0)

Fixes a few small bugs, and adds support for relative $refs when using a URI as the input.

Features

Bug fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.13.0…v0.14.0 

20 Sept 2024 (v0.13.0)

This release adds support for schemas specifying default values, and begins validating / parsing incoming request headers. Note: this may be a breaking change if your server currently accepts requests with invalid request headers.

Features

Docs

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.12.1…v0.13.0 

17 Aug 2024 (v0.12.1)

This release fixes a small typing mistake preventing queries parameters of type number[] from building properly, and fixes bugs in the handling of header parameters / defaults and the “escape hatch” parameters allowing arbitrary fetch / axios request options to be passed.

It’s also the first release with automated end-to-end tests in place, though the coverage is still low - this will be improved during the course of development going forward.

Bug fixes

Testing

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.12.0…v0.12.1 

5 Aug 2024 (v0.12.0)

Another small release, adding a new CLI parameter OPENAPI_REMOTE_SPEC_REQUEST_HEADERS / --remote-spec-request-headers that allows request headers to be sent when fetching specifications from remote URI’s.

This makes it possible to generate from a remote URI that is behind some form of header based authentication, eg: Authorization: Bearer <bla> (which includes cookie based authentication since cookies are just a Cookie header, and basic auth as this is just Authorization: Basic <credentials>).

The headers are scoped to specific domains/urls such that you can mix and match sources without leaking tokens to the wrong servers.

Features

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.11.2…v0.12.0 

29 Jul 2024 (v0.11.2)

This is a bug fix release, solving an issue with the order schemas were output when generating from specifications that are split over multiple files, causing variable used before declaration issues.

Bug fixes

Documentation

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.11.1…v0.11.2 

27 Jul 2024 (v0.11.1)

This is a bug fix release, containing a solution for https://github.com/mnahkies/openapi-code-generator/issues/217 .

Previously query parameters of an array type did not work when a single element was provided, now this will be parsed and handed to the route handler as an array of one element.

Bug fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.11.0…v0.11.1 

8 Jun 2024 (v0.11.0)

This release contains 1 bug fix for default header handling in typescript-axios and several internal refactoring changes required to facilitate the work-in-progress documentation playground 

Also dropped eslint for biome because I can’t be bothered figuring out the eslint@^9 upgrade / configuration migration.

Bug fixes

Internal refactoring

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.10.0…v0.11.0 

25 May 2024 (v0.10.0)

This release is primarily bug fixes, and internal refactoring to facilitate improvements to documentation. Most effort has gone into the new documentation site live at https://openapi-code-generator.nahkies.co.nz/ 

It also splits the cli from the library entrypoint such that you can now import {generate} from '@nahkies/openapi-code-generator' for programmatic usage if you wish, and improves handling of boolean cli flags.

BREAKING CHANGES There are several potentially breaking changes here:

  • Dropped the “safe edit region” functionality, I doubt anyone was using this and it wasn’t particularly robust
  • Improved handling of additionalProperties / {} schemas to better align with the specification
  • Joi validation became stricter for strings with format email / date-time

This may make some schemas / types change type to unknown, and start serializing/deserializing values that were previously stripped (see #200). If you want more permissive types (any) in these situations rather than unknown you can use the --ts-allow-any cli flag.

Bug fixes

Internal refactoring

Docs

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.9.0…v0.10.0 

27 Apr 2024 (v0.9.0)

There are two new features in this release:

  • Typespec  can now be used as an input file by passing --input-type=typespec as an additional arg
  • You can now use a url for your input file (openapi specs only, typespec must be local files)

Features

Bug fixes

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.8.0…v0.9.0 

7 Apr 2024 (v0.8.0)

There are three main features in this release:

  • Improve json schema validation support for string, number, array (min / max / etc)
  • Make boolean schema validation stricter
  • Start using a pre-compiled ajv validator for better performance

BREAKING CHANGES Previously any truthy value would be accepted for a boolean, eg: any-string would parse to true. Now its parsed like:

  • true | "true" | 1 -> true
  • false | "false" | 0 -> false
  • anything else -> error

Features

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.7.0…v0.8.0 

3 Mar 2024 (v0.7.0)

Features

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.6.0…v0.7.0 

19 Feb 2024 (v0.6.0)

Features

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.5.0…v0.6.0 

10 Feb 2024 (v0.5.0)

Features

Misc

Upgrading notes You may need to replace the Context type from koa with RouterContext from @koa/router in some cases due to changes in the upstream type definitions.

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.4.0…v0.5.0 

5 Jan 2024 (v0.4.0)

Bugs

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.3.0…v0.4.0 

2 Dec 2023 (v0.3.0)

Breaking Changes Errors thrown during request handling in typescript-koa will now be wrapped in KoaRuntimeError objects with the original exception included as the cause, in order to provide additional context about where the error was thrown.

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.2.0…v0.3.0 

12 Nov 2023 (v0.2.0)

Features

Bug Fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.1.1…v0.2.0 

11 Nov 2023 (v0.1.1)

Breaking changes

Fixes

Misc

Full Changelog: https://github.com/mnahkies/openapi-code-generator/compare/v0.1.0…v0.1.1 

1 Oct 2023 (v0.1.0)

Initial Release.

Full Changelog: https://github.com/mnahkies/openapi-code-generator/commits/v0.1.0 

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