0Pricing
LangChain / RAG / Vector DBs · Lesson

Building Custom Output Parsers

Transform raw LLM text into reliable structured data with custom and built-in LangChain output parsers.

Why Parse Output?

LLMs return free-form text, but applications need structured data: objects, lists, enums. An output parser converts the raw string into something your code can use safely.

The Parser Interface

A LangChain output parser implements two key methods.

  • parse(text) turns the string into your type
  • get_format_instructions() tells the model how to format its reply

All lessons in this course

  1. Developing Custom Document Loaders
  2. Integrating Custom Embedding Models
  3. Extending Retrieval Chains with Custom Logic
  4. Building Custom Output Parsers
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