Source: https://seerepo.com/r/langchain4j/langchain4j
Markdown source: https://seerepo.com/r/langchain4j/langchain4j.md
Description: langchain4j/langchain4j is a Java repo with 584,417 lines written. AI signed 1.2% of the 4,320 commits of langchain4j.

# What's inside langchain4j/langchain4j

langchain4j/langchain4j is a Java repo with 584,417 lines written. langchain4j is built with org.jetbrains.kotlin:kotlin-stdlib and org.graalvm.polyglot:polyglot and uses Postgres, MySQL, MongoDB, and 6 more. AI signed 1.2% of the 4,320 commits of langchain4j.

Its description on GitHub: “LangChain4j is an idiomatic, open-source Java library for building LLM-powered applications on the JVM. It offers a unified API over popular LLM providers and vector stores, and makes implementing tool calling (including MCP support), agents and RAG easy. It integrates seamlessly with enterprise Java frameworks like Quarkus and Spring Boot.”

Java · Apache-2.0 · 13,378 stars · GitHub: https://github.com/langchain4j/langchain4j

Read on November 10, 2026, at commit 6840c4a.

## More on this repo

- [What is langchain4j built with?](https://seerepo.com/r/langchain4j/langchain4j/built): langchain4j is built with org.jetbrains.kotlin:kotlin-stdlib and org.graalvm.polyglot:polyglot and uses Postgres, MySQL, MongoDB, and 6 more.
- [How much of langchain4j did AI write?](https://seerepo.com/r/langchain4j/langchain4j/ai): AI signed 1.2% of the 4,320 commits of langchain4j.

## In figures

- 584,417 lines written: The ones people and agents wrote: product, tests, schemas and tooling. Generated code doesn’t count.
- 2,020 source files: The same as the lines: product, tests, schemas and tooling. What’s generated doesn’t count.
- 1,838 test files: The files that test the code.
- 73 technologies: Each service with the file and line that prove it.

SeeRepo read the facts in its code and kept none of it. AI only helps sort its packages and folders by their names, and never sees its code.

## Frequently asked questions

### What is langchain4j/langchain4j?

langchain4j/langchain4j is a Java repo with 584,417 lines written. Its description on GitHub: “LangChain4j is an idiomatic, open-source Java library for building LLM-powered applications on the JVM. It offers a unified API over popular LLM providers and vector stores, and makes implementing tool calling (including MCP support), agents and RAG easy. It integrates seamlessly with enterprise Java frameworks like Quarkus and Spring Boot.”

The proof: [its page on GitHub](https://github.com/langchain4j/langchain4j)

### What is langchain4j built with?

langchain4j is built with org.jetbrains.kotlin:kotlin-stdlib and org.graalvm.polyglot:polyglot and uses Postgres, MySQL, MongoDB, and 6 more.

The proof: [each service with its file and line](https://seerepo.com/r/langchain4j/langchain4j/built)

### How much of langchain4j did AI write?

AI signed 1.2% of the 4,320 commits of langchain4j.

The proof: [the commits each tool signed](https://seerepo.com/r/langchain4j/langchain4j/ai)

### What license does langchain4j have?

langchain4j is released under the Apache-2.0 license.

The proof: [its page on GitHub](https://github.com/langchain4j/langchain4j)

### How many stars does langchain4j have on GitHub?

langchain4j had 13,378 stars on GitHub on November 10, 2026.

The proof: [its page on GitHub](https://github.com/langchain4j/langchain4j)

## Add this badge to your README

It links to this page and updates itself each time SeeRepo reads the repo.

```markdown
[![langchain4j/langchain4j on SeeRepo](https://seerepo.com/badge/langchain4j/langchain4j.svg)](https://seerepo.com/r/langchain4j/langchain4j?de=insignia)
```

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.