The LangChain package is used to facilitate the call to Llama2 hosted on OctoAI
Note We will be using OctoAI to run the examples here. You will need to first sign into OctoAI with your Github or Google account, then create a free API token here that you can use for a while (a month or $10 in OctoAI credits, whichever one runs out first). After the free trial ends, you will need to enter billing info to continue to use Llama2 hosted on OctoAI.
We start by installing the necessary packages:
!pip install llama-index langchain
# use ServiceContext to configure the LLM used and the custom embeddings
from llama_index import ServiceContext
# VectorStoreIndex is used to index custom data
from llama_index import VectorStoreIndex
from langchain.llms.octoai_endpoint import OctoAIEndpoint
Next we set up the OctoAI token.
from getpass import getpass
import os
OCTOAI_API_TOKEN = getpass()
os.environ["OCTOAI_API_TOKEN"] = OCTOAI_API_TOKEN
In this example we will use the YOU.com search engine to augment the LLM's responses. To use the You.com Search API, you can email api@you.com to request an API key.
YOUCOM_API_KEY = getpass()
os.environ["YOUCOM_API_KEY"] = YOUCOM_API_KEY
We then call the Llama 2 model from OctoAI.
We will use the Llama 2 13b chat FP16 model. You can find more on Llama 2 models on the OctoAI text generation solution page.
At the time of writing this notebook the following Llama models are available on OctoAI:
# set llm to be using Llama2 hosted on OctoAI
llama2_13b = "llama-2-13b-chat-fp16"
llm = OctoAIEndpoint(
endpoint_url="https://text.octoai.run/v1/chat/completions",
model_kwargs={
"model": llama2_13b,
"messages": [
{
"role": "system",
"content": "You are a helpful, respectful and honest assistant."
}
],
"max_tokens": 500,
"top_p": 1,
"temperature": 0.01
},
)
Using our api key we set up earlier, we make a request from YOU.com for live data on a particular topic.
import requests
query = "Meta Connect" # you can try other live data query about sports score, stock market and weather info
headers = {"X-API-Key": os.environ["YOUCOM_API_KEY"]}
data = requests.get(
f"https://api.ydc-index.io/search?query={query}",
headers=headers,
).json()
# check the query result in JSON
import json
print(json.dumps(data, indent=2))
We then use the JSONLoader
to extract the text from the returned data. The JSONLoader
gives us the ability to load the data into LamaIndex.
In the next cell we show how to load the JSON result with key info stored as "snippets".
However, you can also add the snippets in the query result to documents like below:
from llama_index import Document
snippets = [snippet for hit in data["hits"] for snippet in hit["snippets"]]
documents = [Document(text=s) for s in snippets]
This can be handy if you just need to add a list of text strings to doc
# one way to load the JSON result with key info stored as "snippets"
from llama_index import download_loader
JsonDataReader = download_loader("JsonDataReader")
loader = JsonDataReader()
documents = loader.load_data([hit["snippets"] for hit in data["hits"]])
With the data set up, we create a vector store for the data and a query engine for it.
For our embeddings we will use HuggingFaceEmbeddings
whose default embedding model is sentence-transformers/all-mpnet-base-v2. This model provides a good balance between speed and performance.
To change the default model, call HuggingFaceEmbeddings(model_name=<another_embedding_model>)
.
For more info see https://huggingface.co/blog/mteb.
# use HuggingFace embeddings
from langchain.embeddings.huggingface import HuggingFaceEmbeddings
from llama_index.embeddings import LangchainEmbedding
embeddings = LangchainEmbedding(HuggingFaceEmbeddings())
print(embeddings)
# create a ServiceContext instance to use Llama2 and custom embeddings
service_context = ServiceContext.from_defaults(llm=llm, chunk_size=800, chunk_overlap=20, embed_model=embeddings)
# create vector store index from the documents created above
index = VectorStoreIndex.from_documents(documents, service_context=service_context)
# create query engine from the index
query_engine = index.as_query_engine(streaming=False)
We are now ready to ask Llama 2 a question about the live data using our query engine.
# ask Llama2 a summary question about the search result
response = query_engine.query("give me a summary")
print(str(response))
# more questions
print(str(query_engine.query("what products were announced")))
print(str(query_engine.query("tell me more about Meta AI assistant")))
print(str(query_engine.query("what are Generative AI stickers")))