US Business Index data API
Every page here is also machine-readable. The dataset is served as static JSON, no key required, built from public sources.
Endpoints
| Endpoint | Returns |
|---|---|
/api/companies.json | Index of all 5,106 companies (slug, name, state, industry, type, ticker) |
/api/companies/{slug}.json | Full record for one company |
/api/companies/state/{state}.json | All companies in a state |
/api/graph.json | Corporate graph: parent/subsidiary and company/person edges |
Examples
GET https://statecompanyindex.com/api/companies.json
GET https://statecompanyindex.com/api/companies/1st-source.json
GET https://statecompanyindex.com/api/companies/state/texas.json
GET https://statecompanyindex.com/api/graph.jsonFor AI and agents
See /llms.txt for a compact map of the dataset and /llms-full.txt for the extended version. The static JSON above is the queryable surface.
Free tier
Everything on this page is free with no key required, and stays that way. Every field in every company record is already public here, the paid tier below sells convenience and throughput, not access to data that's otherwise hidden.
Pro tier (in development, not yet live)
| Feature | Free | Pro |
|---|---|---|
| Per-company / per-state / graph JSON | Yes | Yes |
| Single bulk export (all 5,106 records, one file) | — | Yes |
| Rate limit | Reasonable use, unmetered | Higher, key-based quota |
| Webhooks on data updates | — | Yes |
| Price | Free | TODO, not set |
The Pro tier's gating logic and rate limiting are built as a reference implementation but not deployed, this site is static with no server-side compute today, so gating a paid endpoint requires moving that endpoint to a serverless/edge platform. That platform, the key/quota storage, and the payment processor are deliberately not chosen yet, see the repo's serverless/ directory for the real, working reference code and the open decisions.