enrichment · Listed · Found · 8 endpoints · Gateway-eligible
BuiltWith x402 Pay-per-Call API
BuiltWith x402 Pay-per-Call API
For one-off agent research, choose the narrowest /agent operation and use its documented HTTP method and input. Every /agent operation costs $0.0495; GET /agent/domain accepts query parameters and the other /agent calls accept JSON bodies. No account, API key, payer field, or prepaid key is needed. Send the intended input on the first request, read the x402 v2 challenge from PAYMENT-REQUIRED, sign it for Base USDC, and retry the identical request with PAYMENT-SIGNATURE. Validation and upstream failures are not settled. Use /agent/company-domains before /agent/domain when only a company name is known, /agent/technology-search to resolve a concept to BuiltWith technology names, and /agent/ask for natural-language website discovery. High-volume callers may instead buy prepaid credits through the BuiltWith MCP server. Fixed-price List passes are separate products for List API and committed Ask access.
Indexed from this operator's public /.well-known/x402.json. Found is not operator-owned and is not attested. Claim or opt out.
Agent Read · Cleared Index
ROUTE
Route when you need enrichment at published x402 prices.
confidence
78%
source
signal
Index before you pay. Same payload for agents:
GET /api/cleared/agent-read?slug=builtwith-x402-pay-per-call-api-pt0z
When to call
- Need enrichment via x402 and want Cleared-indexed payTo with a live scorecard.
- Single-call floor around $0.0495.
- For one-off agent research, choose the narrowest /agent operation and use its documented HTTP method and input. Every /agent operation costs $0.0495; GET /agent/domain accepts query parameters and the other /agent calls accept JSON bodies. No account, API key, payer field, or prepaid key is needed. Send the intended input on the first request, read the x402 v2 challenge from PAYMENT-REQUIRED, sign it for Base USDC, and retry the identical request with PAYMENT-SIGNATURE. Validation and upstream failures are not settled. Use /agent/company-domains before /agent/domain when only a company name is known, /agent/technology-search to resolve a concept to BuiltWith technology names, and /agent/ask for natural-language website discovery. High-volume callers may instead buy prepaid credits through the BuiltWith MCP server. Fixed-price List passes are separate products for List API and committed Ask access.
Risks
- Found — not operator-owned; claim status unknown.
- No Cleared settlement receipt on file yet.
- No Gateway traffic yet — market share unproven.
Price posture
Published floor $0.0495 across 8 endpoints.
Category · Gateway
enrichment · no Gateway routes yet — early / unproven on Cleared market share.
Endpoint hints
GET /agent/domainReturn BuiltWith technology detections and metadata for one domain. Useful for company research, stack analysis, competitive intelligence, and sales qualificati
POST /agent/relationshipsFind domains related through shared identifiers, infrastructure, analytics, ownership signals, and other BuiltWith relationship evidence.
POST /agent/changesReturn historical technology changes for one domain, optionally constrained by a human-readable time boundary such as 'last month'.
POST /agent/company-domainsResolve a company or brand name to associated website domains before running domain-level research.
POST /agent/tagsReturn domains connected to a BuiltWith tag such as an IP address or infrastructure attribute.
POST /agent/recommendationsReturn technology recommendations inferred from a domain's existing stack and comparable sites.
POST /agent/redirectsReturn redirect destinations observed for a domain, useful for brand, migration, acquisition, and asset research.
POST /agent/keywordsReturn keywords and topical signals associated with one website domain.
Evidence (Cleared)
- → Intake verified · Gateway-eligible
- → Trust 70/100 · pass · tier listed
- → Protocol mpp
- → Manifest reachable · schema valid
- → Found listing — indexed from public x402.json, not operator-attested.
Endpoints
Look up a domain's technologies and metadata
$0.0495GET https://api.builtwith.com/agent/domainReturn BuiltWith technology detections and metadata for one domain. Useful for company research, stack analysis, competitive intelligence, and sales qualification.
Find websites related to a domain
Not used$0.0495POST https://api.builtwith.com/agent/relationshipsFind domains related through shared identifiers, infrastructure, analytics, ownership signals, and other BuiltWith relationship evidence.
Get technology additions and removals for a domain
Not used$0.0495POST https://api.builtwith.com/agent/changesReturn historical technology changes for one domain, optionally constrained by a human-readable time boundary such as 'last month'.
Find domains associated with a company name
$0.0495POST https://api.builtwith.com/agent/company-domainsResolve a company or brand name to associated website domains before running domain-level research.
Find related domains from an IP address or attribute
$0.0495POST https://api.builtwith.com/agent/tagsReturn domains connected to a BuiltWith tag such as an IP address or infrastructure attribute.
Recommend technologies for a domain
$0.0495POST https://api.builtwith.com/agent/recommendationsReturn technology recommendations inferred from a domain's existing stack and comparable sites.
Get live and historical redirects for a domain
$0.0495POST https://api.builtwith.com/agent/redirectsReturn redirect destinations observed for a domain, useful for brand, migration, acquisition, and asset research.
Get keyword data for a domain
$0.0495POST https://api.builtwith.com/agent/keywordsReturn keywords and topical signals associated with one website domain.
Checks
reachable
valid
2026-08-25T02:00:10.004Z
No settlement evidence found in chain signals.
Gateway routing
Verified (or paid Cleared) — Gateway may route this origin before pay.
Claim this listing to upgrade to Cleared attestation.
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