Kalshi official SDKs: what they do, what they cost, where they stop

What they do

The packages are generated from Kalshi's OpenAPI specification, so every documented REST endpoint is present with typed request and response models. Sync and async Python variants are separate packages. Releases track the spec and, per the docs, are generally published Tuesday to Wednesday each week ahead of the corresponding API changes.

PyPI metadata for both Python packages reads version 3.29.0, published August 25, 2026, with 30 releases since December 2, 2025 and a Python 3.13 or newer requirement. The npm package has 29 versions since September 11, 2025 and was updated September 1, 2026.

• Install: pip install kalshi_python_sync, pip install kalshi_python_async, npm install kalshi-typescript.
• The PyPI summary text still reads as generator scaffolding: "Manually defined OpenAPI spec for endpoints being migrated to spec-first approach".
• Package metadata links a Kalshi/exchange-infra repository that does not appear among the Kalshi GitHub organization's public repos.
• The official Kalshi/kalshi-starter-code-python repo (99 stars) is example code and states it is not an SDK; it shows request signing and authenticated calls from plain Python, which is the production path Kalshi's docs recommend.

Pricing

Free to install. Licensing is uneven: PyPI lists LicenseRef-Proprietary for both Python packages, and npm lists Unlicense for kalshi-typescript. Source is not published on GitHub, so treat the Python packages as closed.

Venues and data

Kalshi only. Coverage follows the REST OpenAPI spec (v3.29.0). WebSocket streaming is specified separately in Kalshi's AsyncAPI document; whether the generated packages wrap it was not verifiable from the package pages.

Where they fall short

Kalshi says it plainly: the SDKs are updated periodically and may lag the API, and active traders should treat the specs as the source of truth. The generated code carries no retry logic, no local order book and no pandas helpers, which is the gap pykalshi and kalshi-python-sdk fill; pykalshi's comparison table lists WebSocket streaming, retries and rate-limit handling as absent from the official package.

Python 3.13+ is the strictest floor of any Kalshi client reviewed here, and the proprietary license blocks vendoring or patching.

Who should use them

Teams that want first-party code and weekly spec parity, and are prepared to wrap retries and streaming themselves.

Traders who need WebSockets, FIX, Perps or DataFrames out of the box should use kalshi-python-sdk or pykalshi.