langchaingo

LangChain Go is a Go-language implementation of LangChain, a widely used toolkit originally written in Python for building applications that rely on large language models. Large language models are the AI systems that power things like ChatGPT and similar chat products.

The library gives Go developers a way to connect to AI model providers, such as OpenAI, Google Gemini, and locally-run models via Ollama, and combine them into complete applications. The basic idea is composability: you wire together a model connection, some logic for handling prompts and responses, and optional memory or storage, to build things like chatbots, document question-answering tools, or any program that sends text to an AI and does something useful with the output.

A short code snippet in the README shows the core pattern: initialize an OpenAI connection, send a prompt, and print the AI's response. The actual API covers much more than that single example. The project's documentation site and Go package reference contain the full details, and a folder of example programs in the repository covers more practical use cases including integration with Gemini and Ollama.

The README is brief, pointing mainly to external resources and community blog posts. The project is community-maintained and actively looking for contributors. It describes itself as a port of Python's LangChain patterns into idiomatic Go, with support for multiple AI model providers through a shared interface, so you can swap providers without rewriting your application's core logic.