# LangChain **Domain:** Artificial Intelligence / Agent Frameworks **Doc Type:** Technology and Project-Archaeology Node **Maturity:** Historical Connection Pending Recovery **Related:** [[wiki/Natural Language to DSL Compilation|Natural Language to DSL Compilation]], [[wiki/Intermediate Representation|Intermediate Representation]], [[wiki/Artificial Intelligence|Artificial Intelligence]] --- ## Definition **LangChain is an open-source framework for building applications and agents around language models, model providers, and tools.** Its current architecture and recommended APIs have changed over time, so recovered project notes should be interpreted against the LangChain version in use when they were written. ## DO-Land Context Bryant reports that he experimented with LangChain in DO land as a way to parse natural-language intentions before translating them into DO operations. The exact code, prompts, version, and mapping strategy have not yet been recovered into this note. Future source material should establish whether LangChain supplied parsing, chaining, tool selection, memory, or another orchestration role. The architectural destination remains clear regardless of framework: natural language may propose an inspectable DO intermediate representation; the capability contract validates it; permissions authorize effects; the host executes registered operations. ## Recovery Questions - Which LangChain language and version was used? - Where are the prompts, chains, parsers, schemas, or tool definitions? - Did the experiment emit textual DO, a structured object, or both? - Which DO commands and scopes were mapped? - Which examples succeeded or failed? ## See Also [[projects/XDO - Executable Markdown and Portable Workflows|XDO]], [[wiki/Domain-Specific Language|Domain-Specific Language]], [[wiki/Capability Registry|Capability Registry]], [Official LangChain overview](https://docs.langchain.com/oss/python/langchain/overview), [[wiki/Technical Terms|Technical Terms]]