Intermediate9 min

Streaming v2

Unified StreamPart protocol, type-safe output modes, and real-time token streaming.

Quick Reference

→version='v2' streaming: unified StreamPart objects with .event and .data fields
→stream_mode='values': emits full state after each super-step
→stream_mode='updates': emits only the delta (changed keys) from each node
→stream_mode='messages': emits individual LLM tokens for real-time UI streaming
→Multiple modes: stream_mode=['updates', 'messages'] to get both in one stream

The v2 Streaming Protocol

Three stream modes: values (snapshots), updates (deltas), messages (tokens)

v2 streaming is the standard

version='v2' returns typed StreamPart objects with .event and .data fields. Each part is self-describing -- you know what kind of event it is (values, updates, messages, custom, debug) without guessing. v1 returned raw tuples and dicts; v2 is structured, typed, and extensible.

Basic v2 streaming loop

Stream Modes

Mode	What It Emits	When To Use
values	Full state snapshot after each super-step	Dashboards, debugging, full state tracking
updates	Only the delta (changed keys) from each node	Progress indicators, lightweight monitoring
messages	Individual LLM tokens as they are generated	Chat UIs, real-time token streaming
custom	User-defined events from get_stream_writer()	Progress bars, status updates, custom events
debug	Internal graph execution details	Development debugging, performance profiling

Combining Multiple Modes

Get progress updates AND token streaming in one loop

Sign in to read this article

This is a premium article. Sign in with your Google account to continue.