Query FEC campaign finance data using the OpenFEC API

Steps

1. Register for a free API key at api.open.fec.gov/developers/; include it as the api_key query parameter on every request.
2. To find candidates, call GET https://api.open.fec.gov/v1/candidates/ with parameters such as cycle=2026, office=H or office=S, and party to filter by election cycle, office, and party affiliation.
3. To retrieve financial totals for a candidate, call GET https://api.open.fec.gov/v1/candidates/{candidate_id}/totals/ which returns raised, spent, and cash-on-hand figures aggregated by cycle.
4. To search individual contributions (Schedule A), call GET https://api.open.fec.gov/v1/schedules/schedule_a/ with filters such as contributor_name, recipient_committee_id, or two_year_transaction_period=2026.
5. Paginate using the per_page parameter (max 100) and the last_index value from each response to retrieve subsequent pages; the API uses cursor-based pagination for schedule endpoints.
6. Data is updated nightly; for real-time filing data use the raw filing endpoints or subscribe to FEC RSS feeds, as the processed API endpoints may lag by up to 24 hours.