# ogen

> ogen is an Apache-2.0 OpenAPI v3 code generator for Go, maintained by the
> ogen-go organization. It reads an OpenAPI v3 document at build time and emits
> a statically typed Go client and server — code-generated JSON encoding (no
> reflection, no `interface{}`), code-generated validators, a static radix
> router, sum types for `oneOf`, `Opt`/`Nil`/`OptNil` wrappers instead of
> pointers, a typed `SecuritySource` interface, webhook client and server
> generation, Server-Sent Events client generation, and OpenTelemetry tracing
> and metrics. ogen operates no hosted API: there is no base URL, no
> authentication, no rate limit and no pricing. Its machine-readable contract is
> the published JSON Schema for its own configuration file.

Generated by API Evangelist on 2026-08-06 from ogen's public documentation,
repositories and package registries. This is an independent third-party profile.

## Start here

- [Getting started](https://ogen.dev/docs/intro): install, `go:generate` wiring, first client and server
- [Features](https://ogen.dev/docs/features): what the generator emits and the one documented incompatibility
- [Configuration](https://ogen.dev/docs/config): the `parser` and `generator` sections, feature resolution, filters
- [Specification extensions](https://ogen.dev/docs/spec/extensions): the documented `x-ogen-*` terms
- [FAQ](https://ogen.dev/docs/faq): 404 handler, error handler, `net/http` middleware
- [Examples](https://ogen.dev/docs/examples): optional/nullable handling, sum types, real-world specs
- [Go reference](https://pkg.go.dev/github.com/ogen-go/ogen): the package API

## Machine-readable contracts

- [Configuration JSON Schema (draft-07)](https://raw.githubusercontent.com/ogen-go/ogen/main/schemas/ogen.jsonschema.json)
- [Configuration JSON Schema source (YAML)](https://raw.githubusercontent.com/ogen-go/ogen/main/schemas/ogen.jsonschema.yml)
- [Full reference config](https://github.com/ogen-go/ogen/blob/main/examples/config/example_all.yml)
- [Default config](https://github.com/ogen-go/ogen/blob/main/examples/config/default_all.yml)
- [Feature list](https://github.com/ogen-go/ogen/blob/main/gen/features.go)

## Install

- Go tool directive (Go 1.24+, pins the version): `go get -tool github.com/ogen-go/ogen/cmd/ogen@latest`
- Go install: `go install -v github.com/ogen-go/ogen/cmd/ogen@latest`
- [Container image](https://github.com/ogen-go/ogen/pkgs/container/ogen): `ghcr.io/ogen-go/ogen:latest`

## Try it

- [OpenAPI validator](https://ogen.dev/docs/validator): the real ogen parser compiled to WebAssembly, runs entirely in the browser, no signup
- [Sample project](https://github.com/ogen-go/example): runnable client, server and OpenTelemetry integration
- [Petstore starter spec](https://raw.githubusercontent.com/ogen-go/web/main/examples/petstore.yml)

## Source and releases

- [ogen-go/ogen](https://github.com/ogen-go/ogen): the generator (Apache-2.0)
- [Releases](https://github.com/ogen-go/ogen/releases): semver, notes per tag, compare links
- [ogen-go/web](https://github.com/ogen-go/web): the ogen.dev documentation site
- [ogen-go/example](https://github.com/ogen-go/example): sample project
- [ogen-go/protoc-gen-oas](https://github.com/ogen-go/protoc-gen-oas): generate OpenAPI v3 from protobuf
- [ogen-go/ent2ogen](https://github.com/ogen-go/ent2ogen): ent schema to ogen
- [ogen-go/schemacompiler](https://github.com/ogen-go/schemacompiler): compile JSON Schema Draft 2020-12 for Go codegen

## Support and security

- [Issues](https://github.com/ogen-go/ogen/issues)
- [Discussions](https://github.com/ogen-go/ogen/discussions)
- [Telegram @ogen_dev](https://t.me/ogen_dev)
- [Contributing](https://github.com/ogen-go/ogen/blob/main/CONTRIBUTING.md)
- [Security policy](https://github.com/ogen-go/ogen/blob/main/SECURITY.md): report privately via GitHub Security Advisories

## API Evangelist profile artifacts

- [apis.yml](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/apis.yml)
- [Packages](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/packages/ogen-packages.yml)
- [CLI surface](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/cli/ogen-cli.yml)
- [Config JSON Schema](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/json-schema/ogen-config.jsonschema.json)
- [Extension vocabulary](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/vocabulary/ogen-extensions.yml)
- [Conformance](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/conformance/ogen-conformance.yml)
- [Lifecycle](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/lifecycle/ogen-lifecycle.yml)
- [Changelog](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/changelog/ogen-changelog.yml)
- [Sandbox](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/sandbox/ogen-sandbox.yml)
- [Vulnerability disclosure](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/security/ogen-vulnerability-disclosure.yml)
- [Agent skills](https://raw.githubusercontent.com/api-evangelist/ogen/refs/heads/main/skills/_index.yml)

## Notes for agents

- There is nothing to call. ogen is invoked as a command against a local
  OpenAPI file; do not attempt to construct HTTP requests to ogen.dev.
- Version acceptance matters: whether a document generates depends on the pinned
  ogen version. Report it with any verdict.
- OpenAPI 3.1 support is partial. See the conformance artifact before declaring
  a 3.1 document invalid.
- `duration` maps to Go `time.Duration`, not the RFC 3339 duration JSON Schema
  defines. This divergence is documented by the project.