OpenAI's API, but make it Kotlin-native
A Kotlin multiplatform client that wraps OpenAI's API in coroutines instead of leaving you to wrestle with raw HTTP.

What it does
openai-kotlin is a typed client for OpenAI’s API built on Kotlin coroutines and Ktor. It covers the full surface area: chat, images, embeddings, audio, fine-tuning, batch jobs, and the newer Assistants/Threads/Vector Stores beta. You bring a Ktor engine (OkHttp, CIO, etc.) and an API key; the library handles the rest.
The interesting bit
Multiplatform is the real pitch. The same dependency works in commonMain for JVM, JS, and WASM targets, with per-platform engine selection. That’s rarer than it should be in the LLM client space, where most libraries are JVM-only or Python-first afterthoughts.
Key highlights
- Coroutine-native: suspending functions throughout, no callback soup
- Multiplatform:
commonMaindependency with per-target Ktor engines - BOM support for Gradle version alignment (Maven users are out of luck here)
- ProGuard/R8 rules bundled in the JAR
- Live integration tests exist but are opt-in and billable; offline tests run by default
Caveats
- Unofficial and unaffiliated with OpenAI; API drift is your problem
- Gradle required for multiplatform; JVM-only Maven usage is possible but second-class
- Some features (Assistants, Vector Stores) are still in beta
Verdict
Kotlin developers building cross-platform or server-side LLM features should look here first. If you’re already in Python or don’t need multiplatform, this is just another API wrapper.
Frequently asked
- What is aallam/openai-kotlin?
- A Kotlin multiplatform client that wraps OpenAI's API in coroutines instead of leaving you to wrestle with raw HTTP.
- Is openai-kotlin open source?
- Yes — aallam/openai-kotlin is open source, released under the MIT license.
- What language is openai-kotlin written in?
- aallam/openai-kotlin is primarily written in Kotlin.
- How popular is openai-kotlin?
- aallam/openai-kotlin has 1.8k stars on GitHub.
- Where can I find openai-kotlin?
- aallam/openai-kotlin is on GitHub at https://github.com/aallam/openai-kotlin.