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Topic

LangChain Structured Output & Parsers

12 posts on langchain structured output & parsers — part of framework tutorials on the n4n AI blog.

Framework tutorialsGuide

Type-safe LLM responses in LangChain with Pydantic

Build type-safe LLM pipelines with LangChain and Pydantic — schemas, parsers, validation, streaming, and the gotchas that bite in production.

4 min read
Framework tutorialsTutorial

Structured output on Claude 3.5 Sonnet via LangChain

A hands-on tutorial for getting structured JSON output from Claude 3.5 Sonnet using LangChain's Pydantic parsers and tool calling, with runnable code at every step.

2 min read
Framework tutorialsHow-to

Stream structured output in LangChain with n4n.ai

Learn to stream structured output in LangChain with Pydantic models and JSON parsers, including partial parsing, validation, and production fallback patterns.

4 min read
Framework tutorialsHow-to

Retry failed LangChain parses with RetryOutputParser

Learn to wrap LangChain parsers with RetryOutputParser so malformed LLM output gets corrected automatically — complete with Pydantic models, prompt templates, and verification steps.

3 min read
Framework tutorialsGuide

LangChain PydanticOutputParser: a complete guide

A practical guide to LangChain's PydanticOutputParser with code examples, common pitfalls, and production patterns for reliable structured LLM output.

5 min read
Framework tutorialsComparison

LangChain output parsers: Pydantic vs JSON vs XML

Compare LangChain output parsers — Pydantic, JSON, and XML — across validation, ergonomics, streaming, and failure modes to pick the right one for your LLM pipeline.

6 min read
Framework tutorialsHow-to

Fix malformed JSON in LangChain with OutputFixingParser

Learn to fix malformed JSON from LLMs using LangChain's OutputFixingParser with practical code examples and production patterns.

4 min read
Framework tutorialsGuide

Structured output in LangChain with Pydantic and n4n.ai

Step-by-step langchain structured output pydantic tutorial: bind typed schemas to LLM calls, validate responses, and handle provider failures in production.

4 min read
Framework tutorialsTutorial

LangChain with_structured_output explained step by step

Hands-on langchain with_structured_output tutorial: define Pydantic schemas, bind to chat models, parse LLM responses, and avoid common pitfalls.

3 min read
Framework tutorialsTutorial

LangChain function calling for data extraction

Hands-on langchain function calling structured extraction tutorial: use Pydantic and with_structured_output to parse text into typed objects.

2 min read
Framework tutorialsHow-to

Force JSON mode in LangChain using n4n.ai models

Learn to force JSON mode in LangChain via the n4n.ai OpenAI-compatible gateway, with runnable code for structured output and validation across 240+ models.

3 min read
Framework tutorialsTutorial

Build a LangChain extraction chain with Pydantic v2

Hands-on langchain extraction chain pydantic v2 tutorial: build a structured output pipeline with Pydantic v2 and LangChain, with runnable code.

2 min read