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How to create a ChromaDB collection

Q: How to create a ChromaDB collection

To create a ChromaDB collection, use the chromadb.Client from the chromadb Python package and call client.create_collection(name="your_collection_name"). This initializes a new collection where you can add and query vectors.

Quick answer

To create a ChromaDB collection, use the chromadb.Client from the chromadb Python package and call client.create_collection(name="your_collection_name"). This initializes a new collection where you can add and query vectors.

PREREQUISITES

Python 3.8+
pip install chromadb
Basic knowledge of Python

Setup

Install the chromadb Python package using pip and import the client. No API key is required for local usage.

bash

pip install chromadb

Step by step

This example shows how to create a ChromaDB collection named my_collection and verify its creation.

python

import chromadb

# Initialize the Chroma client
client = chromadb.Client()

# Create a new collection
collection = client.create_collection(name="my_collection")

# Print collection info
print(f"Collection created with name: {collection.name}")

# List all collections to verify
collections = client.list_collections()
print("Existing collections:")
for col in collections:
    print(f"- {col.name}")

output

Collection created with name: my_collection
Existing collections:
- my_collection

Common variations

You can specify metadata when creating a collection using the metadata parameter.
Use client.get_collection(name="my_collection") to retrieve an existing collection.
ChromaDB supports async usage with asyncio if you use the async client variant.

python

import chromadb

client = chromadb.Client()

# Create collection with metadata
collection = client.create_collection(
    name="my_collection_with_meta",
    metadata={"description": "Test collection"}
)

print(collection.metadata)

# Retrieve existing collection
existing = client.get_collection(name="my_collection_with_meta")
print(f"Retrieved collection: {existing.name}")

output

{'description': 'Test collection'}
Retrieved collection: my_collection_with_meta

Troubleshooting

If you get an error like CollectionAlreadyExistsError, use get_collection instead of create_collection.
Ensure the chromadb package is up to date to avoid compatibility issues.
For persistent storage, configure ChromaDB with a persistent client instead of the default in-memory client.

✅

Key Takeaways

Use chromadb.Client().create_collection(name) to create a new collection.
Collections can include optional metadata for better organization.
Use get_collection to avoid errors if the collection already exists.
Install chromadb via pip for easy Python integration.
Check your client configuration for persistence if needed.

Verified 2026-04

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