Principle:Langchain ai Langchain Incremental Chunk Processing

Knowledge Sources	LangChain
Domains	Streaming, API_Integration
Last Updated	2026-02-11 00:00 GMT

Overview

The provider-specific translation of streaming API responses into standardized LangChain chunk objects.

Description

Each provider's streaming API returns data in its own format (Server-Sent Events, chunked HTTP, etc.). Incremental chunk processing converts each provider-specific chunk into a ChatGenerationChunk containing an AIMessageChunk. This normalization enables consistent downstream processing regardless of the provider.

Usage

This is handled internally by the provider's _stream() method. Users interact with the normalized AIMessageChunk objects.

Theoretical Basis

# Abstract algorithm (not real code)
for raw_chunk in provider_stream:
    content_delta = raw_chunk.choices[0].delta.content
    tool_call_delta = raw_chunk.choices[0].delta.tool_calls
    yield ChatGenerationChunk(
        message=AIMessageChunk(content=content_delta, tool_call_chunks=...)
    )

Related Pages

Implemented By

• Implementation:Langchain_ai_Langchain_BaseChatOpenAI_Stream_Implementation