> ## Documentation Index
> Fetch the complete documentation index at: https://docs.charmos.io/llms.txt
> Use this file to discover all available pages before exploring further.

# LangChain Adapter

Use the LangChain adapter when your agent is built as a LangChain chain, runnable, or agent object.

## Manifest

```yaml theme={"theme":{"light":"min-light","dark":"min-dark"}}
runtime:
  adapter:
    type: "langchain"
    entry_point: "src.main:chain"
```

## Runtime Behavior

Charm loads the entry point and forwards the user's input payload into the LangChain object. The result is converted into a response the Store can display.

## Best For

* Prompt chains.
* Tool-using LangChain agents.
* RAG workflows.
* Existing LangChain projects you want to package for Charm.

## Notes

* Declare required model and tool keys in `runtime.adapter.environment_variables`.
* Keep outputs JSON-serializable when possible.
* Use `mode: "full"` only if you need browser or multimedia dependencies.