# Source URLs — OpenSecrets source card

- OpenSecrets API / open-data page: https://www.opensecrets.org/open-data/api
- OpenSecrets homepage/about pages checked; some direct pages returned Cloudflare/403 in terminal.
- ProPublica Nonprofit Explorer, EIN 52-1275227: https://projects.propublica.org/nonprofits/organizations/521275227
- ProPublica Nonprofit API mirror: https://projects.propublica.org/nonprofits/api/v2/organizations/521275227.json
- InfluenceWatch profile for Center for Responsive Politics / OpenSecrets: https://www.influencewatch.org/non-profit/center-for-responsive-politics/
- Wikipedia overview used only for background cross-checking: https://en.wikipedia.org/wiki/OpenSecrets