3spread/py3spread

py3spread is a Python client library for the 3spread API, which gives access to machine readable data pulled from official SEC filings, including insider stock transactions, large fund holdings, ownership disclosures, and more. API keys are free for individual users, giving access to every dataset at a generous rate limit of 36,000 requests per hour. The service itself is currently in public beta, meaning it is live and usable but still being refined. Its historical data currently goes back to filings accepted in early 2021, and the README is upfront that there can be gaps in coverage across different filing types and time periods, along with occasional parsing errors. The client includes a coverage endpoint so users can check what data is actually available rather than assuming it exists. Using the library is straightforward: after installing it with pip and setting an API key, you create a client object and call methods like client.filings.list or client.insiders.iter_transactions to pull data, with the iter style methods automatically handling pagination behind the scenes. The README shows several example uses of this data, such as comparing how similar different investment managers' stock holdings are to each other, reconstructing a stock's price history purely from insider trade filings, and tracking money market fund yields over time using regulatory reports, each with a linked example notebook. The library organizes data into named resources, one for each major SEC filing type, such as insider filings, institutional holdings, fund portfolios, and beneficial ownership reports. It also includes a changefeed system so a downstream database can stay updated by polling for new filing events. Errors from the API are converted into specific Python exception types, and common transient failures are retried automatically. The project requires Python 3.10 or newer and includes a test suite for contributors.