In-process & embedded engines · chDB (open-source project)
chDB
In-process OLAP SQL engine powered by ClickHouse, embedded directly in Python with no server to install.
chDB embeds ClickHouse's columnar, vectorized query engine as an in-process library rather than a server a client connects to: pip install chdb gives a Python process the ability to run ClickHouse SQL directly against local files or in-memory data, minimizing data-copy overhead between C++ and Python via memoryview. It reads and writes Parquet, CSV, JSON, Arrow, ORC and dozens of other formats without a separate loading step, and exposes a pandas-compatible query API alongside a Python DB-API 2.0 interface. Functionally it does for ClickHouse's analytical engine what SQLite does for transactional workloads, and what DuckDB does independently: bring a full-featured SQL engine into the same process as the calling application instead of requiring a cluster. It also runs in the browser via WebAssembly. chDB currently targets Python on macOS and Linux and is free, open-source software with no vendor pricing page.
At a glance
| Vendor | chDB (open-source project) |
|---|---|
| Pricing model | Open source + paid options |
| Free tier | Yes |
| Deployment | Self-hosted |
| Open source | Yes (Apache-2.0) |
| Best for | Python users wanting ClickHouse-grade analytical SQL locally without standing up a ClickHouse cluster. |
Pricing
Free, open-source library with no hosted product or pricing page.
Pricing has not been verified yet — see the vendor's site.
Features
- In-process ClickHouse SQL engine, no server required
- Vectorized, columnar query execution
- Reads/writes Parquet, CSV, JSON, Arrow, ORC and more
- Pandas-compatible query API
- Python DB-API 2.0 support
- Runs in-browser via WebAssembly
Integrations
Profile last reviewed September 21, 2026