# Koog

> JetBrains' Kotlin and Java framework for predictable, fault-tolerant AI agents across JVM, Android, iOS and the browser.

## Facts
- **Category:** [Agent Frameworks](https://agentsearchengine.app/category/agent-frameworks)
- **Type:** Framework
- **Pricing:** Open source
- **GitHub stars:** 4,591
- **Language:** Kotlin
- **License:** Apache-2.0
- **Last repo activity:** today (Sep 22, 2026)
- **Official site:** https://docs.koog.ai
- **Source code:** https://github.com/JetBrains/koog
- **Listing on Agent Search Engine:** https://agentsearchengine.app/agents/koog
- **Data verified:** September 2026

## Best for
JVM and Android teams that want agents in their own stack rather than in Python.

## Avoid if
Your team works mainly in Python or TypeScript, where larger agent ecosystems exist.

## About Koog
Koog, from JetBrains, builds and runs AI agents in idiomatic Kotlin and Java. It deploys across JVM, JS, WasmJS, Android and iOS through Kotlin Multiplatform, recovers from failures with retries and agent-state persistence, compresses conversation history to save tokens, and integrates with JVM frameworks such as Spring Boot and Ktor.

## Alternatives
Koog sits in agent frameworks. Related tools indexed here:
- [langchain](https://agentsearchengine.app/agents/langchain) — The agent engineering platform. · Open source · Framework · 147k★ · Python · MIT · active today
- [ruflo](https://agentsearchengine.app/agents/ruflo) — The leading agent meta-harness. Deploy intelligent multi-player swarms, coordinate autonomous workflows, and build conversational AI systems. · Open source · Framework · 73k★ · TypeScript · MIT · active 1 day ago
- [MetaGPT](https://agentsearchengine.app/agents/metagpt) — A multi-agent framework that assigns software-company roles to LLM agents to turn a requirement into a project. · Open source · Framework · 71k★ · Python · MIT · active 8 months ago
- [autogen](https://agentsearchengine.app/agents/autogen) — A programming framework for agentic AI; upstream is in maintenance mode. · Open source · Framework · 61k★ · Python · CC-BY-4.0 · active 5 months ago
- [crewAI](https://agentsearchengine.app/agents/crewai) — Framework for orchestrating role-playing, autonomous AI agents. By fostering collaborative intelligence, CrewAI empowers agents to work together seamlessly, tackling complex tasks. · Open source · Framework · 59k★ · Python · MIT · active today
- [LlamaIndex](https://agentsearchengine.app/agents/llamaindex) — Framework for connecting LLMs and agents to your own documents and data. · Open source · Framework · 52k★ · MIT · active today
- [LangGraph](https://agentsearchengine.app/agents/langgraph-platform) — LangChain's low-level orchestration framework for stateful, controllable agents. · Open source · Framework · 42k★ · Python · MIT · active today
- [DSPy](https://agentsearchengine.app/agents/dspy) — Stanford's framework for programming, not prompting, language models, with optimisers for prompts and weights. · Open source · Framework · 38k★ · Python · MIT · active today

---
Source: [Agent Search Engine](https://agentsearchengine.app) — an independent, hand-curated index of AI agents, MCP servers, and frameworks. Rankings are never sold; sponsored placements are labeled and never numbered. Full directory: https://agentsearchengine.app/llms-full.txt