BuiltWith

Key facts

Card

https://builtwith.com/.well-known/agent-card.json

Card version

A2A v0.3 shape

Interfaces

• HTTP+JSON, protocol version 0.3.0, at api.builtwith.com

Streaming

Yes

Push notifications

No

Extended card

No

Authentication

HTTP Bearer, http:x402

Signed

No

Provider

BuiltWith Pty Ltd

Documentation

https://api.builtwith.com/llms.txt

Tranco rank

15,822

Last seen

September 26, 2026

Skills

• Accountless x402 USDC access

  Run fixed-price BuiltWith lookups without an account or API key. Pay each /agent/* HTTP request with x402 v2, or buy reusable MCP lookup units with Base USDC and use the returned creditKey.

  Id x402-usdc-access · Tags: x402, USDC, Base, pay-per-call, accountless

• Domain technology profile

  Look up the full technology stack detected on a website, including current and historical technologies, first/last detected dates, categories, and metadata.

  Id domain-technology-profile · Tags: technology-lookup, tech-stack, domain, metadata

• Technology change tracking

  Report technologies added, dropped, or changed on a website over time, and the redirects associated with a domain.

  Id technology-changes · Tags: change-tracking, added, dropped, redirects

• Website relationships

  Discover relationships between websites — shared analytics, advertising, hosting, and tracking identifiers that link domains to the same owner or network.

  Id website-relationships · Tags: relationships, ownership, connected-sites

• Technology lists and trends

  List and rank the websites using a specific technology, with adoption trends over time, market share, and tag-based segmentation.

  Id technology-lists-and-trends · Tags: lists, trends, market-share, adoption

• Company and firmographics

  Resolve a company name to its primary website, and retrieve firmographic, financial, social, traffic, and trust signals for a domain.

  Id company-and-firmographics · Tags: company, firmographics, financial, social, trust, traffic

• Keywords and recommendations

  Retrieve the keywords a website ranks for, search websites by keyword, and get technology recommendations for a domain.

  Id keywords-and-recommendations · Tags: keywords, search, recommendations

• Natural-language site discovery

  Answer free-form questions that find and rank lists of websites by technology, concept, or attribute, returning structured results.

  Id natural-language-site-discovery · Tags: ask, discovery, semantic-search, vector

Check this agent

Run the card through the validator, or send the agent a few harmless test calls. Each tool opens with builtwith.com filled in.