langchainx

AgentExecutor, ChatAgent (ReAct), OpenAIToolsAgent, and the Agent trait.

JOB-251 — Why Arc<dyn LLM> over LLMClone, migration pattern, and correct LLM ownership model.

All Chain types — LLMChain, ConversationalChain, SequentialChain, StuffDocuments, ConversationalRetrievalQA, SqlDatabaseChain.

Trait conformance tests, property-based tests (proptest), fuzz targets, and boundary contracts for langchainx traits.

Core langchainx patterns — LLMChain, builder pattern, Chain trait, prompt macros, and basic invocation.

Constructing LLM backends (OpenAI, Claude, DeepSeek, Qwen, Ollama) and configuring CallOptions.

JOB-256 — blanket From impl, removing redundant Into impls, RwLock vs Mutex for memory.

BaseMemory trait, memory types (SimpleMemory, WindowBufferMemory, DummyMemory), and Arc<Mutex> construction patterns.

JOB-254 — PromptArgs pitfalls, required key validation, and typed input patterns.

VectorStore trait, Embedder trait, Retriever, document loaders, and ConversationalRetrievalQA.

JOB-253 — correct streaming pattern via stream() return value; removing streaming_func side-channel.

JOB-257 — FakeLLM, in-process test doubles, writing offline chain/agent tests.

Implementing the Tool trait, defining parameters JSON schema, and registering tools with AgentExecutor.

JOB-252 — async_trait overhead, native async fn in traits (Rust 1.75+), and when each applies.

JOB-255 — replacing Box<dyn Error> on Tool::run with typed ToolError, thiserror patterns.