Cohere

Cohere is a Canadian startup that provides natural language processing models that help companies improve human-machine interactions.

Head to the API reference for detailed documentation of all attributes and methods.

Setup

The integration lives in the langchain-community package. We also need to install the cohere package itself. We can install these with:

pip install -U langchain-community langchain-cohere

We'll also need to get a Cohere API key and set the COHERE_API_KEY environment variable:

import getpass
import os

os.environ["COHERE_API_KEY"] = getpass.getpass()

 ········

It's also helpful (but not needed) to set up LangSmith for best-in-class observability

# os.environ["LANGCHAIN_TRACING_V2"] = "true"
# os.environ["LANGCHAIN_API_KEY"] = getpass.getpass()

Cohere supports all LLM functionality:

from langchain_cohere import Cohere
from langchain_core.messages import HumanMessage

model = Cohere(model="command", max_tokens=256, temperature=0.75)

message = "Knock knock"
model.invoke(message)

" Who's there?"

await model.ainvoke(message)

" Who's there?"

for chunk in model.stream(message):
    print(chunk, end="", flush=True)

 Who's there?

model.batch([message])

[" Who's there?"]

You can also easily combine with a prompt template for easy structuring of user input. We can do this using LCEL

from langchain_core.prompts import PromptTemplate

prompt = PromptTemplate.from_template("Tell me a joke about {topic}")
chain = prompt | model

chain.invoke({"topic": "bears"})

' Why did the teddy bear cross the road?\nBecause he had bear crossings.\n\nWould you like to hear another joke? '