richlai commited on
Commit
8046bed
·
1 Parent(s): dc4ca5c
Files changed (8) hide show
  1. .env.sample +5 -0
  2. .gitignore +6 -0
  3. Dockerfile +11 -0
  4. app.py +210 -0
  5. chainlit.md +1 -0
  6. data/paul_graham_essays.txt +0 -0
  7. requirements.txt +132 -0
  8. solution_app.py +190 -0
.env.sample ADDED
@@ -0,0 +1,5 @@
 
 
 
 
 
 
1
+ # !!! DO NOT UPDATE THIS FILE DIRECTLY. MAKE A COPY AND RENAME IT `.env` TO PROCEED !!! #
2
+ HF_LLM_ENDPOINT="YOUR_LLM_ENDPOINT_URL_HERE"
3
+ HF_EMBED_ENDPOINT="YOUR_EMBED_MODEL_ENDPOINT_URL_HERE"
4
+ HF_TOKEN="YOUR_HF_TOKEN_HERE"
5
+ # !!! DO NOT UPDATE THIS FILE DIRECTLY. MAKE A COPY AND RENAME IT `.env` TO PROCEED !!! #
.gitignore ADDED
@@ -0,0 +1,6 @@
 
 
 
 
 
 
 
1
+ .env
2
+ __pycache__/
3
+ .chainlit
4
+ *.faiss
5
+ *.pkl
6
+ .files
Dockerfile ADDED
@@ -0,0 +1,11 @@
 
 
 
 
 
 
 
 
 
 
 
 
1
+ FROM python:3.9
2
+ RUN useradd -m -u 1000 user
3
+ USER user
4
+ ENV HOME=/home/user \
5
+ PATH=/home/user/.local/bin:$PATH
6
+ WORKDIR $HOME/app
7
+ COPY --chown=user . $HOME/app
8
+ COPY ./requirements.txt ~/app/requirements.txt
9
+ RUN pip install -r requirements.txt
10
+ COPY . .
11
+ CMD ["chainlit", "run", "app.py", "--port", "7860"]
app.py ADDED
@@ -0,0 +1,210 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import os
2
+ import chainlit as cl
3
+ from dotenv import load_dotenv
4
+ from operator import itemgetter
5
+ from langchain_huggingface import HuggingFaceEndpoint
6
+ from langchain_community.document_loaders import TextLoader
7
+ from langchain_text_splitters import RecursiveCharacterTextSplitter
8
+ from langchain_community.vectorstores import FAISS
9
+ from langchain_huggingface import HuggingFaceEndpointEmbeddings
10
+ from langchain_core.prompts import PromptTemplate
11
+ from langchain.schema.output_parser import StrOutputParser
12
+ from langchain.schema.runnable import RunnablePassthrough
13
+ from langchain.schema.runnable.config import RunnableConfig
14
+ from tqdm.asyncio import tqdm_asyncio
15
+ import asyncio
16
+ from tqdm.asyncio import tqdm
17
+
18
+ # GLOBAL SCOPE - ENTIRE APPLICATION HAS ACCESS TO VALUES SET IN THIS SCOPE #
19
+ # ---- ENV VARIABLES ---- #
20
+ """
21
+ This function will load our environment file (.env) if it is present.
22
+
23
+ NOTE: Make sure that .env is in your .gitignore file - it is by default, but please ensure it remains there.
24
+ """
25
+ load_dotenv()
26
+
27
+ """
28
+ We will load our environment variables here.
29
+ """
30
+ HF_LLM_ENDPOINT = os.environ["HF_LLM_ENDPOINT"]
31
+ HF_EMBED_ENDPOINT = os.environ["HF_EMBED_ENDPOINT"]
32
+ HF_TOKEN = os.environ["HF_TOKEN"]
33
+
34
+ # ---- GLOBAL DECLARATIONS ---- #
35
+
36
+ # -- RETRIEVAL -- #
37
+ """
38
+ 1. Load Documents from Text File
39
+ 2. Split Documents into Chunks
40
+ 3. Load HuggingFace Embeddings (remember to use the URL we set above)
41
+ 4. Index Files if they do not exist, otherwise load the vectorstore
42
+ """
43
+ # 1. CREATE TEXT LOADER AND LOAD DOCUMENTS
44
+ # NOTE: PAY ATTENTION TO THE PATH THEY ARE IN.
45
+ text_loader = TextLoader("./data/paul_graham_essays.txt")
46
+ documents = text_loader.load()
47
+
48
+ # 2. CREATE TEXT SPLITTER AND SPLIT DOCUMENTS
49
+ text_splitter = RecursiveCharacterTextSplitter(
50
+ chunk_size=1000, chunk_overlap=30)
51
+ split_documents = text_splitter.split_documents(documents)
52
+
53
+ # 3. LOAD HUGGINGFACE EMBEDDINGS
54
+ hf_embeddings = HuggingFaceEndpointEmbeddings(
55
+ model=HF_EMBED_ENDPOINT,
56
+ task="feature-extraction",
57
+ token=HF_TOKEN
58
+ )
59
+
60
+
61
+ async def add_documents_async(vectorstore, documents):
62
+ await vectorstore.aadd_documents(documents)
63
+
64
+
65
+ async def process_batch(vectorstore, batch, is_first_batch, pbar):
66
+ if is_first_batch:
67
+ result = await FAISS.afrom_documents(batch, hf_embeddings)
68
+ else:
69
+ await add_documents_async(vectorstore, batch)
70
+ result = vectorstore
71
+ pbar.update(len(batch))
72
+ return result
73
+
74
+
75
+ async def main():
76
+ print("Indexing Files")
77
+
78
+ vectorstore = None
79
+ batch_size = 32
80
+
81
+ batches = [split_documents[i:i+batch_size]
82
+ for i in range(0, len(split_documents), batch_size)]
83
+
84
+ async def process_all_batches():
85
+ nonlocal vectorstore
86
+ tasks = []
87
+ pbars = []
88
+
89
+ for i, batch in enumerate(batches):
90
+ pbar = tqdm(total=len(batch), desc=f"Batch {
91
+ i+1}/{len(batches)}", position=i)
92
+ pbars.append(pbar)
93
+
94
+ if i == 0:
95
+ vectorstore = await process_batch(None, batch, True, pbar)
96
+ else:
97
+ tasks.append(process_batch(vectorstore, batch, False, pbar))
98
+
99
+ if tasks:
100
+ await asyncio.gather(*tasks)
101
+
102
+ for pbar in pbars:
103
+ pbar.close()
104
+
105
+ await process_all_batches()
106
+
107
+ hf_retriever = vectorstore.as_retriever()
108
+ print("\nIndexing complete. Vectorstore is ready for use.")
109
+ return hf_retriever
110
+
111
+
112
+ async def run():
113
+ retriever = await main()
114
+ return retriever
115
+
116
+ hf_retriever = asyncio.run(run())
117
+
118
+ # -- AUGMENTED -- #
119
+ """
120
+ 1. Define a String Template
121
+ 2. Create a Prompt Template from the String Template
122
+ """
123
+ # 1. DEFINE STRING TEMPLATE
124
+ RAG_PROMPT_TEMPLATE = """\
125
+ <|start_header_id|>system<|end_header_id|>
126
+ You are a helpful assistant. You answer user questions based on provided context. If you can't answer the question with the provided context, say you I don't know.<|eot_id|>
127
+
128
+ <|start_header_id|>user<|end_header_id|>
129
+ User Query:
130
+ {query}
131
+
132
+ Context:
133
+ {context}<|eot_id|>
134
+
135
+ <|start_header_id|>assistant<|end_header_id|>
136
+ """
137
+
138
+ # 2. CREATE PROMPT TEMPLATE
139
+ rag_prompt = PromptTemplate.from_template(RAG_PROMPT_TEMPLATE)
140
+
141
+ # -- GENERATION -- #
142
+ """
143
+ 1. Create a HuggingFaceEndpoint for the LLM
144
+ """
145
+ # 1. CREATE HUGGINGFACE ENDPOINT FOR LLM
146
+ hf_llm = HuggingFaceEndpoint(
147
+ endpoint_url=HF_LLM_ENDPOINT,
148
+ max_new_tokens=512,
149
+ top_k=10,
150
+ top_p=0.95,
151
+ typical_p=0.95,
152
+ temperature=0.01,
153
+ repetition_penalty=1.03,
154
+ huggingfacehub_api_token=os.environ["HF_TOKEN"]
155
+ )
156
+
157
+
158
+ @cl.author_rename
159
+ def rename(original_author: str):
160
+ """
161
+ This function can be used to rename the 'author' of a message.
162
+
163
+ In this case, we're overriding the 'Assistant' author to be 'Paul Graham Essay Bot'.
164
+ """
165
+ rename_dict = {
166
+ "Assistant": "Paul Graham Essay Bot"
167
+ }
168
+ return rename_dict.get(original_author, original_author)
169
+
170
+
171
+ @cl.on_chat_start
172
+ async def start_chat():
173
+ """
174
+ This function will be called at the start of every user session.
175
+
176
+ We will build our LCEL RAG chain here, and store it in the user session.
177
+
178
+ The user session is a dictionary that is unique to each user session, and is stored in the memory of the server.
179
+ """
180
+
181
+ # BUILD LCEL RAG CHAIN THAT ONLY RETURNS TEXT
182
+ lcel_rag_chain = (
183
+ {"context": itemgetter("query") | hf_retriever,
184
+ "query": itemgetter("query")}
185
+ | rag_prompt | hf_llm
186
+ )
187
+
188
+ cl.user_session.set("lcel_rag_chain", lcel_rag_chain)
189
+
190
+
191
+ @cl.on_message
192
+ async def main(message: cl.Message):
193
+ """
194
+ This function will be called every time a message is recieved from a session.
195
+
196
+ We will use the LCEL RAG chain to generate a response to the user query.
197
+
198
+ The LCEL RAG chain is stored in the user session, and is unique to each user session - this is why we can access it here.
199
+ """
200
+ lcel_rag_chain = cl.user_session.get("lcel_rag_chain")
201
+
202
+ msg = cl.Message(content="")
203
+
204
+ async for chunk in lcel_rag_chain.astream(
205
+ {"query": message.content},
206
+ config=RunnableConfig(callbacks=[cl.LangchainCallbackHandler()]),
207
+ ):
208
+ await msg.stream_token(chunk)
209
+
210
+ await msg.send()
chainlit.md ADDED
@@ -0,0 +1 @@
 
 
1
+ # FILL OUT YOUR CHAINLIT MD HERE WITH A DESCRIPTION OF YOUR APPLICATION
data/paul_graham_essays.txt ADDED
The diff for this file is too large to render. See raw diff
 
requirements.txt ADDED
@@ -0,0 +1,132 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ aiofiles==23.2.1
2
+ aiohappyeyeballs==2.4.3
3
+ aiohttp==3.10.8
4
+ aiosignal==1.3.1
5
+ annotated-types==0.7.0
6
+ anyio==3.7.1
7
+ async-timeout==4.0.3
8
+ asyncer==0.0.2
9
+ attrs==24.2.0
10
+ bidict==0.23.1
11
+ certifi==2024.8.30
12
+ chainlit==0.7.700
13
+ charset-normalizer==3.3.2
14
+ click==8.1.7
15
+ dataclasses-json==0.5.14
16
+ Deprecated==1.2.14
17
+ distro==1.9.0
18
+ exceptiongroup==1.2.2
19
+ faiss-cpu==1.8.0.post1
20
+ fastapi==0.100.1
21
+ fastapi-socketio==0.0.10
22
+ filelock==3.16.1
23
+ filetype==1.2.0
24
+ frozenlist==1.4.1
25
+ fsspec==2024.9.0
26
+ googleapis-common-protos==1.65.0
27
+ greenlet==3.1.1
28
+ grpcio==1.66.2
29
+ grpcio-tools==1.62.3
30
+ h11==0.14.0
31
+ h2==4.1.0
32
+ hpack==4.0.0
33
+ httpcore==0.17.3
34
+ httpx==0.24.1
35
+ huggingface-hub==0.25.1
36
+ hyperframe==6.0.1
37
+ idna==3.10
38
+ importlib_metadata==8.4.0
39
+ Jinja2==3.1.4
40
+ jiter==0.5.0
41
+ joblib==1.4.2
42
+ jsonpatch==1.33
43
+ jsonpointer==3.0.0
44
+ langchain==0.3.0
45
+ langchain-community==0.3.0
46
+ langchain-core==0.3.1
47
+ langchain-huggingface==0.1.0
48
+ langchain-openai==0.2.0
49
+ langchain-qdrant==0.1.4
50
+ langchain-text-splitters==0.3.0
51
+ langsmith==0.1.121
52
+ Lazify==0.4.0
53
+ MarkupSafe==2.1.5
54
+ marshmallow==3.22.0
55
+ mpmath==1.3.0
56
+ multidict==6.1.0
57
+ mypy-extensions==1.0.0
58
+ nest-asyncio==1.6.0
59
+ networkx==3.2.1
60
+ numpy==1.26.4
61
+ nvidia-cublas-cu12==12.1.3.1
62
+ nvidia-cuda-cupti-cu12==12.1.105
63
+ nvidia-cuda-nvrtc-cu12==12.1.105
64
+ nvidia-cuda-runtime-cu12==12.1.105
65
+ nvidia-cudnn-cu12==9.1.0.70
66
+ nvidia-cufft-cu12==11.0.2.54
67
+ nvidia-curand-cu12==10.3.2.106
68
+ nvidia-cusolver-cu12==11.4.5.107
69
+ nvidia-cusparse-cu12==12.1.0.106
70
+ nvidia-nccl-cu12==2.20.5
71
+ nvidia-nvjitlink-cu12==12.6.77
72
+ nvidia-nvtx-cu12==12.1.105
73
+ openai==1.51.0
74
+ opentelemetry-api==1.27.0
75
+ opentelemetry-exporter-otlp==1.27.0
76
+ opentelemetry-exporter-otlp-proto-common==1.27.0
77
+ opentelemetry-exporter-otlp-proto-grpc==1.27.0
78
+ opentelemetry-exporter-otlp-proto-http==1.27.0
79
+ opentelemetry-instrumentation==0.48b0
80
+ opentelemetry-proto==1.27.0
81
+ opentelemetry-sdk==1.27.0
82
+ opentelemetry-semantic-conventions==0.48b0
83
+ orjson==3.10.7
84
+ packaging==23.2
85
+ pillow==10.4.0
86
+ portalocker==2.10.1
87
+ protobuf==4.25.5
88
+ pydantic==2.9.2
89
+ pydantic-settings==2.5.2
90
+ pydantic_core==2.23.4
91
+ PyJWT==2.9.0
92
+ PyMuPDF==1.24.10
93
+ PyMuPDFb==1.24.10
94
+ python-dotenv==1.0.1
95
+ python-engineio==4.9.1
96
+ python-graphql-client==0.4.3
97
+ python-multipart==0.0.6
98
+ python-socketio==5.11.4
99
+ PyYAML==6.0.2
100
+ qdrant-client==1.11.2
101
+ regex==2024.9.11
102
+ requests==2.32.3
103
+ safetensors==0.4.5
104
+ scikit-learn==1.5.2
105
+ scipy==1.13.1
106
+ sentence-transformers==3.1.1
107
+ simple-websocket==1.0.0
108
+ sniffio==1.3.1
109
+ SQLAlchemy==2.0.35
110
+ starlette==0.27.0
111
+ sympy==1.13.3
112
+ syncer==2.0.3
113
+ tenacity==8.5.0
114
+ threadpoolctl==3.5.0
115
+ tiktoken==0.7.0
116
+ tokenizers==0.20.0
117
+ tomli==2.0.1
118
+ torch==2.4.1
119
+ tqdm==4.66.5
120
+ transformers==4.45.1
121
+ triton==3.0.0
122
+ typing-inspect==0.9.0
123
+ typing_extensions==4.12.2
124
+ uptrace==1.26.0
125
+ urllib3==2.2.3
126
+ uvicorn==0.23.2
127
+ watchfiles==0.20.0
128
+ websockets==13.1
129
+ wrapt==1.16.0
130
+ wsproto==1.2.0
131
+ yarl==1.13.1
132
+ zipp==3.20.2
solution_app.py ADDED
@@ -0,0 +1,190 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import os
2
+ import chainlit as cl
3
+ from dotenv import load_dotenv
4
+ from operator import itemgetter
5
+ from langchain_huggingface import HuggingFaceEndpoint
6
+ from langchain_community.document_loaders import TextLoader
7
+ from langchain_text_splitters import RecursiveCharacterTextSplitter
8
+ from langchain_community.vectorstores import FAISS
9
+ from langchain_huggingface import HuggingFaceEndpointEmbeddings
10
+ from langchain_core.prompts import PromptTemplate
11
+ from langchain.schema.output_parser import StrOutputParser
12
+ from langchain.schema.runnable import RunnablePassthrough
13
+ from langchain.schema.runnable.config import RunnableConfig
14
+ from tqdm.asyncio import tqdm_asyncio
15
+ import asyncio
16
+ from tqdm.asyncio import tqdm
17
+
18
+ # GLOBAL SCOPE - ENTIRE APPLICATION HAS ACCESS TO VALUES SET IN THIS SCOPE #
19
+ # ---- ENV VARIABLES ---- #
20
+ """
21
+ This function will load our environment file (.env) if it is present.
22
+
23
+ NOTE: Make sure that .env is in your .gitignore file - it is by default, but please ensure it remains there.
24
+ """
25
+ load_dotenv()
26
+
27
+ """
28
+ We will load our environment variables here.
29
+ """
30
+ HF_LLM_ENDPOINT = os.environ["HF_LLM_ENDPOINT"]
31
+ HF_EMBED_ENDPOINT = os.environ["HF_EMBED_ENDPOINT"]
32
+ HF_TOKEN = os.environ["HF_TOKEN"]
33
+
34
+ # ---- GLOBAL DECLARATIONS ---- #
35
+
36
+ # -- RETRIEVAL -- #
37
+ """
38
+ 1. Load Documents from Text File
39
+ 2. Split Documents into Chunks
40
+ 3. Load HuggingFace Embeddings (remember to use the URL we set above)
41
+ 4. Index Files if they do not exist, otherwise load the vectorstore
42
+ """
43
+ document_loader = TextLoader("./data/paul_graham_essays.txt")
44
+ documents = document_loader.load()
45
+
46
+ text_splitter = RecursiveCharacterTextSplitter(chunk_size=1000, chunk_overlap=30)
47
+ split_documents = text_splitter.split_documents(documents)
48
+
49
+ hf_embeddings = HuggingFaceEndpointEmbeddings(
50
+ model=HF_EMBED_ENDPOINT,
51
+ task="feature-extraction",
52
+ huggingfacehub_api_token=HF_TOKEN,
53
+ )
54
+
55
+ async def add_documents_async(vectorstore, documents):
56
+ await vectorstore.aadd_documents(documents)
57
+
58
+ async def process_batch(vectorstore, batch, is_first_batch, pbar):
59
+ if is_first_batch:
60
+ result = await FAISS.afrom_documents(batch, hf_embeddings)
61
+ else:
62
+ await add_documents_async(vectorstore, batch)
63
+ result = vectorstore
64
+ pbar.update(len(batch))
65
+ return result
66
+
67
+ async def main():
68
+ print("Indexing Files")
69
+
70
+ vectorstore = None
71
+ batch_size = 32
72
+
73
+ batches = [split_documents[i:i+batch_size] for i in range(0, len(split_documents), batch_size)]
74
+
75
+ async def process_all_batches():
76
+ nonlocal vectorstore
77
+ tasks = []
78
+ pbars = []
79
+
80
+ for i, batch in enumerate(batches):
81
+ pbar = tqdm(total=len(batch), desc=f"Batch {i+1}/{len(batches)}", position=i)
82
+ pbars.append(pbar)
83
+
84
+ if i == 0:
85
+ vectorstore = await process_batch(None, batch, True, pbar)
86
+ else:
87
+ tasks.append(process_batch(vectorstore, batch, False, pbar))
88
+
89
+ if tasks:
90
+ await asyncio.gather(*tasks)
91
+
92
+ for pbar in pbars:
93
+ pbar.close()
94
+
95
+ await process_all_batches()
96
+
97
+ hf_retriever = vectorstore.as_retriever()
98
+ print("\nIndexing complete. Vectorstore is ready for use.")
99
+ return hf_retriever
100
+
101
+ async def run():
102
+ retriever = await main()
103
+ return retriever
104
+
105
+ hf_retriever = asyncio.run(run())
106
+
107
+ # -- AUGMENTED -- #
108
+ """
109
+ 1. Define a String Template
110
+ 2. Create a Prompt Template from the String Template
111
+ """
112
+ RAG_PROMPT_TEMPLATE = """\
113
+ <|start_header_id|>system<|end_header_id|>
114
+ You are a helpful assistant. You answer user questions based on provided context. If you can't answer the question with the provided context, say you don't know.<|eot_id|>
115
+
116
+ <|start_header_id|>user<|end_header_id|>
117
+ User Query:
118
+ {query}
119
+
120
+ Context:
121
+ {context}<|eot_id|>
122
+
123
+ <|start_header_id|>assistant<|end_header_id|>
124
+ """
125
+
126
+ rag_prompt = PromptTemplate.from_template(RAG_PROMPT_TEMPLATE)
127
+
128
+ # -- GENERATION -- #
129
+ """
130
+ 1. Create a HuggingFaceEndpoint for the LLM
131
+ """
132
+ hf_llm = HuggingFaceEndpoint(
133
+ endpoint_url=HF_LLM_ENDPOINT,
134
+ max_new_tokens=512,
135
+ top_k=10,
136
+ top_p=0.95,
137
+ temperature=0.3,
138
+ repetition_penalty=1.15,
139
+ huggingfacehub_api_token=HF_TOKEN,
140
+ )
141
+
142
+ @cl.author_rename
143
+ def rename(original_author: str):
144
+ """
145
+ This function can be used to rename the 'author' of a message.
146
+
147
+ In this case, we're overriding the 'Assistant' author to be 'Paul Graham Essay Bot'.
148
+ """
149
+ rename_dict = {
150
+ "Assistant" : "Paul Graham Essay Bot"
151
+ }
152
+ return rename_dict.get(original_author, original_author)
153
+
154
+ @cl.on_chat_start
155
+ async def start_chat():
156
+ """
157
+ This function will be called at the start of every user session.
158
+
159
+ We will build our LCEL RAG chain here, and store it in the user session.
160
+
161
+ The user session is a dictionary that is unique to each user session, and is stored in the memory of the server.
162
+ """
163
+
164
+ lcel_rag_chain = (
165
+ {"context": itemgetter("query") | hf_retriever, "query": itemgetter("query")}
166
+ | rag_prompt | hf_llm
167
+ )
168
+
169
+ cl.user_session.set("lcel_rag_chain", lcel_rag_chain)
170
+
171
+ @cl.on_message
172
+ async def main(message: cl.Message):
173
+ """
174
+ This function will be called every time a message is recieved from a session.
175
+
176
+ We will use the LCEL RAG chain to generate a response to the user query.
177
+
178
+ The LCEL RAG chain is stored in the user session, and is unique to each user session - this is why we can access it here.
179
+ """
180
+ lcel_rag_chain = cl.user_session.get("lcel_rag_chain")
181
+
182
+ msg = cl.Message(content="")
183
+
184
+ for chunk in await cl.make_async(lcel_rag_chain.stream)(
185
+ {"query": message.content},
186
+ config=RunnableConfig(callbacks=[cl.LangchainCallbackHandler()]),
187
+ ):
188
+ await msg.stream_token(chunk)
189
+
190
+ await msg.send()