Streaming

All LLMs implement the Runnable interface, which comes with default implementations of all methods, ie. ainvoke, batch, abatch, stream, astream. This gives all LLMs basic support for streaming.

Streaming support defaults to returning an Iterator (or AsyncIterator in the case of async streaming) of a single value, the final result returned by the underlying LLM provider. This obviously doesn't give you token-by-token streaming, which requires native support from the LLM provider, but ensures your code that expects an iterator of tokens can work for any of our LLM integrations.

See which integrations support token-by-token streaming here.

from langchain_openai import OpenAI

llm = OpenAI(model="gpt-3.5-turbo-instruct", temperature=0, max_tokens=512)
for chunk in llm.stream("Write me a song about sparkling water."):
    print(chunk, end="", flush=True)

Verse 1:
Bubbles dancing in my glass
Clear and crisp, it's such a blast
Refreshing taste, it's like a dream
Sparkling water, you make me beam

Chorus:
Oh sparkling water, you're my delight
With every sip, you make me feel so right
You're like a party in my mouth
I can't get enough, I'm hooked no doubt

Verse 2:
No sugar, no calories, just pure bliss
You're the perfect drink, I must confess
From lemon to lime, so many flavors to choose
Sparkling water, you never fail to amuse

Chorus:
Oh sparkling water, you're my delight
With every sip, you make me feel so right
You're like a party in my mouth
I can't get enough, I'm hooked no doubt

Bridge:
Some may say you're just plain water
But to me, you're so much more
You bring a sparkle to my day
In every single way

Chorus:
Oh sparkling water, you're my delight
With every sip, you make me feel so right
You're like a party in my mouth
I can't get enough, I'm hooked no doubt

Outro:
So here's to you, my dear sparkling water
You'll always be my go-to drink forever
With your effervescence and refreshing taste
You'll always have a special place.