InspeKtor¶

Generate OpenAPI specifications from your Ktor code at compile time.
Zero runtime overhead. Full type safety. Always in sync.

Get Started View on GitHub

Why InspeKtor?¶

Zero Runtime Overhead

Documentation is generated at compile time, not runtime. Your application performance stays completely unaffected.
No third-party DSL

Leverages Ktor's standard syntax to generate route definitions and Kotlin's type system to derive schemas.
Minimal Annotations

Most information is inferred from your code. Add annotations only when you need extra documentation.
Always In Sync

Your documentation is generated from actual code, so it's always accurate and never drifts out of date.

Quick Start¶

1. Add the Plugin¶

build.gradle.kts

plugins {
    kotlin("jvm") version "2.3.0"
    id("io.ktor.plugin") version "3.0.0"
    id("io.github.tabilzad.inspektor") version "0.10.0-alpha"
}

swagger {
    documentation {
        info {
            title = "My API"
            version = "1.0.0"
        }
    }
}

2. Annotate Your Routes¶

Application.kt

@GenerateOpenApi
fun Application.module() {
    routing {
        route("/api/users") {

            @KtorDescription(summary = "List all users")
            get {
                responds<List<User>>(HttpStatusCode.OK)
                // Implementation
            }

            @KtorDescription(summary = "Create user")
            post {
                responds<User>(HttpStatusCode.Created)
                responds<ErrorResponse>(HttpStatusCode.BadRequest)
                val request = call.receive<CreateUserRequest>()
                // Implementation
            }
        }
    }
}

3. Build¶

Bash

./gradlew build

Your OpenAPI spec is generated at build/resources/main/openapi/openapi.yaml

Features at a Glance¶

Feature	Description
Route Detection	Automatically detects routes from Ktor's routing DSL
Schema Generation	Generates schemas from Kotlin data classes
Request Bodies	Infers request schemas from `call.receive<T>()`
Response Types	Documents responses with the `responds<T>()` function
Path Parameters	Detects parameters from `{param}` syntax
Query Parameters	Extracts query parameters from code
KDoc Integration	Extracts descriptions from KDoc comments
Security Schemes	Supports JWT, API Key, OAuth2, and more
Sealed Classes	Full support for polymorphic types with discriminators
Generic Types	Handles generic wrappers like `Response<T>`
Incremental Builds	Configurable regeneration modes for fast builds

Explore the Docs¶

Getting Started

Install InspeKtor and generate your first API spec in minutes.

Installation
Configuration

Customize API info, security schemes, type mappings, and more.

Configuration
Usage Guide

Learn how to document endpoints, responses, and parameters.

Usage Guide
API Reference

Complete reference for annotations, functions, and Gradle DSL.

API Reference