langchain4j-demo

Companion code for the ankurm.com LangChain4j posts. Every number and transcript quoted in a post comes from a file in a module's output/ folder, and the tests that write those files also assert the same facts, so the build fails when a claim stops being true.

Module	Post	What it shows
ai-services	LangChain4j AI Services with Spring Boot 4: Declarative LLM Interfaces	prompt templates, chat memory, tools, RAG, and the @MemoryId trap

Versions (verified on Maven Central, 2026-10-11)

Component	Version	Note
LangChain4j (langchain4j, langchain4j-core, BOM)	1.22.0	GA
LangChain4j beta modules (starters, embeddings, agentic)	1.22.0-beta32	beta only, no GA exists
JDK	25 LTS
JUnit	6.1.3

Run

export JAVA_HOME=/path/to/jdk-25
mvn test

No API key is needed. The tests use ScriptedChatModel, a deterministic stand-in for an LLM, so they can assert exactly which messages LangChain4j sent. Replace it with OpenAiChatModel or any other ChatModel and the AI Service interfaces do not change.

Each module writes its transcripts to <module>/output/ when you run the tests.