LlamaIndex Llms Integration: Openai

Installation

To install the required package, run:

%pip install llama-index-llms-openai

Setup

1. Set your OpenAI API key as an environment variable. You can replace "sk-..." with your actual API key:

import os

os.environ["OPENAI_API_KEY"] = "sk-..."

Basic Usage

Generate Completions

To generate a completion for a prompt, use the complete method:

from llama_index.llms.openai import OpenAI

resp = OpenAI().complete("Paul Graham is ")
print(resp)

Chat Responses

To send a chat message and receive a response, create a list of ChatMessage instances and use the chat method:

from llama_index.core.llms import ChatMessage

messages = [
    ChatMessage(
        role="system", content="You are a pirate with a colorful personality."
    ),
    ChatMessage(role="user", content="What is your name?"),
]
resp = OpenAI().chat(messages)
print(resp)

Streaming Responses

Stream Complete

To stream responses for a prompt, use the stream_complete method:

from llama_index.llms.openai import OpenAI

llm = OpenAI()
resp = llm.stream_complete("Paul Graham is ")
for r in resp:
    print(r.delta, end="")

Stream Chat

To stream chat responses, use the stream_chat method:

from llama_index.llms.openai import OpenAI
from llama_index.core.llms import ChatMessage

llm = OpenAI()
messages = [
    ChatMessage(
        role="system", content="You are a pirate with a colorful personality."
    ),
    ChatMessage(role="user", content="What is your name?"),
]
resp = llm.stream_chat(messages)
for r in resp:
    print(r.delta, end="")

Configure Model

You can specify a particular model when creating the OpenAI instance:

llm = OpenAI(model="gpt-3.5-turbo")
resp = llm.complete("Paul Graham is ")
print(resp)

messages = [
    ChatMessage(
        role="system", content="You are a pirate with a colorful personality."
    ),
    ChatMessage(role="user", content="What is your name?"),
]
resp = llm.chat(messages)
print(resp)

Asynchronous Usage

You can also use asynchronous methods for completion:

from llama_index.llms.openai import OpenAI

llm = OpenAI(model="gpt-3.5-turbo")
resp = await llm.acomplete("Paul Graham is ")
print(resp)

Set API Key at a Per-Instance Level

If desired, you can have separate LLM instances use different API keys:

from llama_index.llms.openai import OpenAI

llm = OpenAI(model="gpt-3.5-turbo", api_key="BAD_KEY")
resp = OpenAI().complete("Paul Graham is ")
print(resp)

LLM Implementation example

https://docs.llamaindex.ai/en/stable/examples/llm/openai/