BuiltWith: 6 reads, one client

What technology a website runs, how that has changed, and which sites are related. Every call below is available over HTTP, through the SDK and as a tool for a coding agent, with the same arguments and the same meter.

What BuiltWith can do here

The integration exposes 6 reads, each with a declared input and output schema rather than a page of documentation you would have to translate. What technology a website runs, how that has changed, and which sites are related.

How it authenticates

BuiltWith authenticates with a apiKey, supplied per request or stored once against your account and sealed at rest. On our side the same value is read from apiKey when we broker the call for you.

Called by name, not by capability

BuiltWith does not currently map onto a vendor-neutral capability, so you call its operations by name. That is the right shape when you genuinely mean this provider — which, for a service with its own model of the world, is most of the time.

• freeLookup — read: The free technology summary for a domain — grouped categories, no detail. The connection test, because it costs nothing.
• domainLookup — read: The full technology profile for a domain — every detected product, with first and last seen dates.
• technologyChanges — read: Sites that recently added or dropped a technology — the trigger feed for a migration-based outreach workflow.
• relationships — read: Other sites sharing analytics, ad or hosting identifiers with this one — the operator behind several brands.
• companyToUrl — read: Find the websites belonging to a named company — the reverse of every other lookup here.
• technologyList — read: Every site running a given technology — the bulk prospecting list.

Questions

Do I have to bring my own API keys?

You can, and that lane is free for ever — pass your key on the request or store it against your account, and we are one proxy hop. The paid lane is the other direction: we call 226 providers with our credentials so you never register anywhere. Both go through the same client and the same operation names.

What happens to a key I store here?

It is sealed with AES-256-GCM before it reaches the database and is only ever opened to make the call you asked for. It is scoped to your account, it is never logged, and deleting the connection deletes it. For an OAuth provider we hold a refresh token instead, and revoking the link at the provider stops the calls here immediately.

What happens when a provider changes its API?

The operation contract is declared, so a response that no longer matches is a refusal rather than a silently wrong answer. The contract does not coerce types — a field declared a number that arrives as a string is rejected at the edge, on the way in and on the way out.