mirror of https://github.com/hwchase17/langchain
templates: Add rag lantern template (#16523)
Replace this entire comment with: - **Description:** Added a template for lantern rag usage. --------- Co-authored-by: Erick Friis <erick@langchain.dev>pull/19248/head
parent
516cc44b3f
commit
7c26ef88a1
@ -0,0 +1 @@
|
||||
.env
|
@ -0,0 +1,129 @@
|
||||
|
||||
# rag_lantern
|
||||
|
||||
This template performs RAG with Lantern.
|
||||
|
||||
[Lantern](https://lantern.dev) is an open-source vector database built on top of [PostgreSQL](https://en.wikipedia.org/wiki/PostgreSQL). It enables vector search and embedding generation inside your database.
|
||||
|
||||
## Environment Setup
|
||||
|
||||
Set the `OPENAI_API_KEY` environment variable to access the OpenAI models.
|
||||
|
||||
To get your `OPENAI_API_KEY`, navigate to [API keys](https://platform.openai.com/account/api-keys) on your OpenAI account and create a new secret key.
|
||||
|
||||
To find your `LANTERN_URL` and `LANTERN_SERVICE_KEY`, head to your Lantern project's [API settings](https://lantern.dev/dashboard/project/_/settings/api).
|
||||
|
||||
- `LANTERN_URL` corresponds to the Project URL
|
||||
- `LANTERN_SERVICE_KEY` corresponds to the `service_role` API key
|
||||
|
||||
|
||||
```shell
|
||||
export LANTERN_URL=
|
||||
export LANTERN_SERVICE_KEY=
|
||||
export OPENAI_API_KEY=
|
||||
```
|
||||
|
||||
## Setup Lantern Database
|
||||
|
||||
Use these steps to setup your Lantern database if you haven't already.
|
||||
|
||||
1. Head to [https://lantern.dev](https://lantern.dev) to create your Lantern database.
|
||||
2. In your favorite SQL client, jump to the SQL editor and run the following script to setup your database as a vector store:
|
||||
|
||||
```sql
|
||||
-- Create a table to store your documents
|
||||
create table
|
||||
documents (
|
||||
id uuid primary key,
|
||||
content text, -- corresponds to Document.pageContent
|
||||
metadata jsonb, -- corresponds to Document.metadata
|
||||
embedding REAL[1536] -- 1536 works for OpenAI embeddings, change as needed
|
||||
);
|
||||
|
||||
-- Create a function to search for documents
|
||||
create function match_documents (
|
||||
query_embedding REAL[1536],
|
||||
filter jsonb default '{}'
|
||||
) returns table (
|
||||
id uuid,
|
||||
content text,
|
||||
metadata jsonb,
|
||||
similarity float
|
||||
) language plpgsql as $$
|
||||
#variable_conflict use_column
|
||||
begin
|
||||
return query
|
||||
select
|
||||
id,
|
||||
content,
|
||||
metadata,
|
||||
1 - (documents.embedding <=> query_embedding) as similarity
|
||||
from documents
|
||||
where metadata @> filter
|
||||
order by documents.embedding <=> query_embedding;
|
||||
end;
|
||||
$$;
|
||||
```
|
||||
|
||||
## Setup Environment Variables
|
||||
|
||||
Since we are using [`Lantern`](https://python.langchain.com/docs/integrations/vectorstores/lantern) and [`OpenAIEmbeddings`](https://python.langchain.com/docs/integrations/text_embedding/openai), we need to load their API keys.
|
||||
|
||||
## Usage
|
||||
|
||||
First, install the LangChain CLI:
|
||||
|
||||
```shell
|
||||
pip install -U langchain-cli
|
||||
```
|
||||
|
||||
To create a new LangChain project and install this as the only package, you can do:
|
||||
|
||||
```shell
|
||||
langchain app new my-app --package rag-lantern
|
||||
```
|
||||
|
||||
If you want to add this to an existing project, you can just run:
|
||||
|
||||
```shell
|
||||
langchain app add rag-lantern
|
||||
```
|
||||
|
||||
And add the following code to your `server.py` file:
|
||||
|
||||
```python
|
||||
from rag_lantern.chain import chain as rag_lantern_chain
|
||||
|
||||
add_routes(app, rag_lantern_chain, path="/rag-lantern")
|
||||
```
|
||||
|
||||
(Optional) Let's now configure LangSmith.
|
||||
LangSmith will help us trace, monitor and debug LangChain applications.
|
||||
LangSmith is currently in private beta, you can sign up [here](https://smith.langchain.com/).
|
||||
If you don't have access, you can skip this section
|
||||
|
||||
```shell
|
||||
export LANGCHAIN_TRACING_V2=true
|
||||
export LANGCHAIN_API_KEY=<your-api-key>
|
||||
export LANGCHAIN_PROJECT=<your-project> # if not specified, defaults to "default"
|
||||
```
|
||||
|
||||
If you are inside this directory, then you can spin up a LangServe instance directly by:
|
||||
|
||||
```shell
|
||||
langchain serve
|
||||
```
|
||||
|
||||
This will start the FastAPI app with a server is running locally at
|
||||
[http://localhost:8000](http://localhost:8000)
|
||||
|
||||
We can see all templates at [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs)
|
||||
We can access the playground at [http://127.0.0.1:8000/rag-lantern/playground](http://127.0.0.1:8000/rag-lantern/playground)
|
||||
|
||||
We can access the template from code with:
|
||||
|
||||
```python
|
||||
from langserve.client import RemoteRunnable
|
||||
|
||||
runnable = RemoteRunnable("http://localhost:8000/rag-lantern")
|
||||
```
|
File diff suppressed because it is too large
Load Diff
@ -0,0 +1,39 @@
|
||||
[tool.poetry]
|
||||
name = "rag-lantern"
|
||||
version = "0.1.0"
|
||||
description = "RAG using Lantern retriver"
|
||||
authors = [
|
||||
"Gustavo Reyes <gustavo@lantern.dev>",
|
||||
]
|
||||
readme = "README.md"
|
||||
|
||||
[tool.poetry.dependencies]
|
||||
python = ">=3.8.1,<4.0"
|
||||
langchain = "^0.1"
|
||||
openai = "<2"
|
||||
tiktoken = "^0.5.1"
|
||||
rag-lantern = {path = "packages/rag-lantern", develop = true}
|
||||
|
||||
[tool.poetry.group.dev.dependencies]
|
||||
langchain-cli = ">=0.0.15"
|
||||
[tool.poetry.group.dev.dependencies.python-dotenv]
|
||||
extras = [
|
||||
"cli",
|
||||
]
|
||||
version = "^1.0.0"
|
||||
|
||||
[tool.langserve]
|
||||
export_module = "rag_lantern.chain"
|
||||
export_attr = "chain"
|
||||
|
||||
[tool.templates-hub]
|
||||
use-case = "rag"
|
||||
author = "Lantern"
|
||||
integrations = ["OpenAI", "Lantern"]
|
||||
tags = ["vectordbs"]
|
||||
|
||||
[build-system]
|
||||
requires = [
|
||||
"poetry-core",
|
||||
]
|
||||
build-backend = "poetry.core.masonry.api"
|
@ -0,0 +1,47 @@
|
||||
from langchain_community.chat_models import ChatOpenAI
|
||||
from langchain_community.embeddings import OpenAIEmbeddings
|
||||
from langchain_community.vectorstores import Lantern
|
||||
from langchain_core.output_parsers import StrOutputParser
|
||||
from langchain_core.prompts import ChatPromptTemplate
|
||||
from langchain_core.pydantic_v1 import BaseModel
|
||||
from langchain_core.runnables import RunnableParallel, RunnablePassthrough
|
||||
|
||||
CONNECTION_STRING = "postgresql://postgres:postgres@localhost:5432"
|
||||
COLLECTION_NAME = "documents"
|
||||
DB_NAME = "postgres"
|
||||
|
||||
embeddings = OpenAIEmbeddings()
|
||||
|
||||
vectorstore = Lantern(
|
||||
collection_name=COLLECTION_NAME,
|
||||
connection_string=CONNECTION_STRING,
|
||||
embedding_function=embeddings,
|
||||
)
|
||||
|
||||
retriever = vectorstore.as_retriever()
|
||||
|
||||
|
||||
template = """Answer the question based only on the following context:
|
||||
{context}
|
||||
|
||||
Question: {question}
|
||||
"""
|
||||
|
||||
prompt = ChatPromptTemplate.from_template(template)
|
||||
|
||||
model = ChatOpenAI()
|
||||
|
||||
chain = (
|
||||
RunnableParallel({"context": retriever, "question": RunnablePassthrough()})
|
||||
| prompt
|
||||
| model
|
||||
| StrOutputParser()
|
||||
)
|
||||
|
||||
|
||||
# Add typing for input
|
||||
class Question(BaseModel):
|
||||
__root__: str
|
||||
|
||||
|
||||
chain = chain.with_types(input_type=Question)
|
Loading…
Reference in New Issue