Chroma similarity_search and similarity_search_with_score do not return any results

[guninder]

Checked other resources

• I added a very descriptive title to this issue.
• I searched the LangChain documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

Example Code

Hi,
I am new to langchain and chroma. I am trying to insert data into chromadb and search it. There is no issue with data. I tried the same search in creating a knowledge base in bedrock. I don't get any error. The database created (data_level0.bin is about 6.3 MB) but while doing a search, it returns empty results. Following is the code to insert the data.

from langchain_chroma import Chroma
from langchain.text_splitter import CharacterTextSplitter
from langchain_community.document_loaders import TextLoader
import os

CHROMA_PATH = "data/chroma_wp"
os.environ["OPENAI_API_KEY"] = "sk-"

loader = TextLoader("books/war_and_peace.txt", encoding="utf-8")
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=200, separator="\n")

chunks = text_splitter.split_documents(documents)
embeddings = OpenAIEmbeddings()
vectorStore = Chroma.from_documents(documents=chunks, embedding=embeddings, persist_directory=CHROMA_PATH)```

Following is the code i am using to search.
```import chromadb
import os
from langchain_chroma import Chroma
from langchain_openai import OpenAIEmbeddings

os.environ["OPENAI_API_KEY"] = "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"
CHROMA_PATH = "data/chroma_wp"

embeddings = OpenAIEmbeddings()
vectorStore = Chroma(persist_directory=CHROMA_PATH, embedding_function=embeddings)
#vectorStore.delete()
print(vectorStore)

results = vectorStore.similarity_search("Who is Andrew?", k=3)
#vectorStore.similarity_search_with_score("Who is Andrew?", k=3)

print(results)

I get empty results.

Following are the packages i am using

langchain 0.3.1

langchain-chroma 0.1.4

langchain-community 0.3.1

langchain-core 0.3.6

langchain-experimental 0.3.2

langchain-openai 0.2.1

langchain-text-splitters 0.3.0

chroma-hnswlib 0.7.6

chromadb 0.5.12

Error Message and Stack Trace (if applicable)

No exception. Just empty results.

Description

Hi,
I am new to langchain and chroma. I am trying to insert data into chromadb and search it. There is no issue with data. I tried the same search in creating a knowledge base in bedrock. I don't get any error. The database created (data_level0.bin is about 6.3 MB) but while doing a search, it returns empty results. Following is the code to insert the data.

from langchain_chroma import Chroma
from langchain.text_splitter import CharacterTextSplitter
from langchain_community.document_loaders import TextLoader
import os

CHROMA_PATH = "data/chroma_wp"
os.environ["OPENAI_API_KEY"] = "sk-"

loader = TextLoader("books/war_and_peace.txt", encoding="utf-8")
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=200, separator="\n")

chunks = text_splitter.split_documents(documents)
embeddings = OpenAIEmbeddings()
vectorStore = Chroma.from_documents(documents=chunks, embedding=embeddings, persist_directory=CHROMA_PATH)```

Following is the code i am using to search.
```import chromadb
import os
from langchain_chroma import Chroma
from langchain_openai import OpenAIEmbeddings

os.environ["OPENAI_API_KEY"] = "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"
CHROMA_PATH = "data/chroma_wp"

embeddings = OpenAIEmbeddings()
vectorStore = Chroma(persist_directory=CHROMA_PATH, embedding_function=embeddings)
#vectorStore.delete()
print(vectorStore)

results = vectorStore.similarity_search("Who is Andrew?", k=3)
#vectorStore.similarity_search_with_score("Who is Andrew?", k=3)

print(results)

I get empty results.

Following are the packages i am using

langchain 0.3.1

langchain-chroma 0.1.4

langchain-community 0.3.1

langchain-core 0.3.6

langchain-experimental 0.3.2

langchain-openai 0.2.1

langchain-text-splitters 0.3.0

chroma-hnswlib 0.7.6

chromadb 0.5.12

System Info

System Information

OS: Windows
OS Version: 10.0.22631
Python Version: 3.10.5 (tags/v3.10.5:f377153, Jun 6 2022, 16:14:13) [MSC v.1929 64 bit (AMD64)]

Package Information

langchain_core: 0.3.6
langchain: 0.3.1
langchain_community: 0.3.1
langsmith: 0.1.129
langchain_chroma: 0.1.4
langchain_experimental: 0.3.2
langchain_openai: 0.2.1
langchain_text_splitters: 0.3.0

Optional packages not installed

langgraph
langserve

Other Dependencies

aiohttp: 3.10.6
async-timeout: 4.0.3
chromadb: 0.5.12
dataclasses-json: 0.6.7
fastapi: 0.115.0
httpx: 0.27.2
jsonpatch: 1.33
numpy: 1.26.4
openai: 1.50.1
orjson: 3.10.7
packaging: 24.1
pydantic: 2.9.2
pydantic-settings: 2.5.2
PyYAML: 6.0.2
requests: 2.32.3
SQLAlchemy: 2.0.35
tenacity: 8.5.0
tiktoken: 0.7.0
typing-extensions: 4.12.2

[iharshlalakiya]

hi,
I can help you with this problem.

[guninder]

iharshlalakiya, thank you. Will appreciate. Please let me know if you need any other information.