03. ChromaDB Setup

Chapter 3 of 18 · 15 min

KEY INSIGHT

ChromaDB stores vectors alongside metadata and provides a Pythonic interface for vector operations without external services. ChromaDB is a dedicated vector database that runs entirely in-process. No server, no Docker, no API keys. It persists data to disk as SQLite under the hood. Install it with pip: ```bash pip install chromadb==0.4.22 ``` The client connects to a persistent database: ```python import chromadb from chromadb.config import Settings # Creates ./chroma_db directory if it doesn't exist client = chromadb.PersistentClient(path="./chroma_db") # Or in-memory (data lost on restart) client = chromadb.Client() ``` ChromaDB version matters. Version 0.4.x changed the API significantly from 0.3.x. The examples here use 0.4.22. Common setup error: trying to use ChromaDB with an older version of the `chromadb` package that conflicts with another dependency. If you see `ImportError: cannot import name 'Client' from 'chromadb'`, check your installed version: ```bash pip show chromadb ``` The ChromaDB package was renamed from `chromadb` to `chromadb`â€”confusing, but make sure you have the correct package installed and not the deprecated `chroma-db` or `chromadb-old` packages from testing phases.

Local verification checkpoint

Run the smallest example from this chapter in a local workspace and record the package version, runtime, data path, and observed output. If the result depends on model size, vector count, CPU/GPU backend, or available memory, note that constraint beside the exercise so the lesson remains reproducible.

Local verification checkpoint

EXERCISE

Install ChromaDB, create a PersistentClient, and verify the database directory was created on disk.