OpenAPI Package

Go types and utilities for building OpenAPI 3.1.0 specifications programmatically.

Features

Supported OpenAPI 3.1.0 Features

• ✅ Complete Specification Support - All OpenAPI 3.1.0 objects implemented
• ✅ JSON Schema Integration - Full schema validation and documentation
• ✅ Multiple Content Types - JSON, XML, form data, file uploads
• ✅ Authentication Schemes - API keys, OAuth2, HTTP auth
• ✅ Response Linking - Connect operations through links
• ✅ Webhooks & Callbacks - Document async operations
• ✅ Examples & Descriptions - Rich documentation with examples

Installation

go get github.com/nyxstack/openapi

Overview

This package provides Go types that represent the complete OpenAPI 3.1.0 specification. You use these types to programmatically build OpenAPI documents, then marshal them to JSON or YAML format.

Usage

Basic Document Creation

package main

import (
    "fmt"
    "github.com/nyxstack/openapi"
)

func main() {
    // Create a new OpenAPI document
    doc := openapi.NewDocument("My API", "1.0.0")
    
    // Add metadata
    doc.WithInfo("A sample API", "").
        WithContact("API Team", "https://example.com", "team@example.com").
        WithLicense("MIT", "https://opensource.org/licenses/MIT")
    
    // Add a server
    doc.AddServer("https://api.example.com", "Production server")
    
    // Build a simple operation
    operation := openapi.NewOperation("getUser", "Get User", "Retrieve user by ID")
    operation.WithPathParameter("id", "User ID", openapi.StringSchema(""))
    operation.WithOkResponse("User found", userSchema())
    
    // Add the operation to a path
    doc.AddOperation("/users/{id}", "GET", operation)
    
    // Marshal to JSON
    jsonBytes, err := doc.ToJSON()
    if err != nil {
        panic(err)
    }
    
    fmt.Println(string(jsonBytes))
}

func userSchema() *openapi.Schema {
    return openapi.NewObjectSchema().
        WithRequiredProperty("id", openapi.StringSchema("")).
        WithProperty("name", openapi.StringSchema("")).
        WithProperty("email", openapi.EmailSchema())
}

Building Complex Schemas

// Create reusable schemas
doc.AddSchema("User", *openapi.NewObjectSchema().
    WithRequiredProperty("id", openapi.StringSchema("")).
    WithRequiredProperty("email", openapi.EmailSchema()).
    WithProperty("name", openapi.StringSchema("")))

// Reference schemas in operations
schema := &openapi.Schema{
    Ref: "#/components/schemas/User",
}

Authentication

// Add Bearer token auth
doc.AddSecurityScheme("bearerAuth", openapi.SecurityScheme{
    Type:         "http",
    Scheme:       "bearer",
    BearerFormat: "JWT",
})

// Apply to operations
operation.Security = []openapi.SecurityRequirement{
    {"bearerAuth": []string{}},
}

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.