Connecticut Business Registry — Business Master: access card

Every endpoint on this page was live-probed on 2026-07-29 by the Aidenix Atlas catalog.

What is the Connecticut business registry?

Connecticut Business Registry — Business Master is the business master file of the Connecticut Secretary of the State, published by Connecticut Secretary of the State. Coverage: United States — Connecticut; scale: 1,280,795 records, according to the catalog manifest. In our data — the Aidenix Atlas catalog, where every source is live-probed — this endpoint answered HTTP 200 on 2026-07-29. What the card gives you:

• The exact endpoint and a working request you can copy.
• Authentication and rate limits: none — no API key required.
• The query keys the source accepts and the fields it returns, verified against the live endpoint.

Key facts at a glance

A key-facts table is the 30-second version of this card: 1,280,795 in scope, 4 query facets, 4 field groups out. Every row comes from our own probe run of 2026-07-29, not from vendor marketing:

How do you query it?

A working query is one plain HTTP request — in our data this exact request form was verified on 2026-07-29:

curl "https://data.ct.gov/resource/n7gp-d28j.json?$limit=10"

The source runs on the Socrata Open Data API, so the query grammar is the same across every Socrata portal:

• Filter with SoQL parameters: $where, $limit, $offset.
• %25 inside a like clause is the wildcard — omit it and you get exact matches only, which is the usual reason a first query returns nothing.
• Page size goes up to 50,000 rows per request.
• A free app token grants a dedicated rate limit, according to Socrata documentation.
• Portal uptime is the weak link: these state endpoints go down occasionally, so a production pipeline needs a retry path.

When should you use this source?

A source fit is a match between what you already know and what the endpoint accepts — 4 query facets here, according to our probe of 2026-07-29. In our data, the decision goes like this:

• If the company is registered in Connecticut → this is the authoritative record, filed with Connecticut Secretary of the State.
• If you can search by company name → this source resolves it directly; other facets need a different registry.
• If you need fields it does not return (company name, dates, owner record, economy fields is the full list) → follow the related sources below rather than forcing this one.

What does it accept and return?

The interface contract is a short one: 4 query facets in, 4 field groups out. Every row below was checked against the live endpoint on 2026-07-29:

Related sources

A related source is a dataset that joins to the Connecticut business registry through a shared key — 3 of them in our catalog of nearly 4,000 sources, each probed on the same schedule as this card, according to our run of 2026-07-29:

• New York Active Corporations dataset — United States — New York.
• Business Entities in Colorado dataset — United States — Colorado.
• Oregon Active Businesses dataset — United States — Oregon.

The workflow this source belongs to is covered in the full guide: Free US company registry APIs — state-by-state guide.

Frequently asked questions

Three questions cover most of what people ask about this source. Answers below reflect our probe of 2026-07-29:

Is the Connecticut business registry free to use? Yes — $0 license fee, 1,280,795 in scope, authentication: none — no API key required. The cost of using it is engineering time and rate-limit patience, not money.

How current is the data? The records are as current as Connecticut Secretary of the State makes them — registries update on filing schedules, not news cycles. What we verify is the endpoint: it answered on 2026-07-29, and this card carries that date so you can tell a fresh claim from a stale one.

Can I use this commercially? Public records generally allow commercial use, but terms are set per publisher, not universally. Query-and-enrich workloads are uncontroversial; verify Connecticut Secretary of the State's specific terms before redistributing bulk copies.

How we verify this card

Our verification method is a live probe, not a citation chain — the status on this card comes from a real request we sent on 2026-07-29. What the probe run covers, in our data:

• Endpoint liveness: this source is one of the nearly 4,000 the Aidenix Atlas catalog tracks, re-probed on schedule.
• Contract checks: the accepted query facets and returned field groups above are read from the live response, not from documentation.
• Honest failures: when a source stops answering, this card says so and its date freezes — we do not publish a fresh-looking date over a dead endpoint.
• Freshness contract: the «last probe» date above is the promise; it moves only when the source actually answers.

Source card generated from the Aidenix Atlas catalog; facts as probed on 2026-07-29.