Deterministic extraction — no LLM, no hallucinated vendors
The vendor-stack intelligence API.
A multi-source extraction pipeline reads an entity's public web presence and returns a structured list of vendors with quoted evidence.
Paste the skill into Claude, ChatGPT or Cursor — the agent gets its own key and starts querying. No signup step.
{
"domain": "notify-hq.com",
"found": true,
"cache": "hit",
"vendor_stack": {
"payments": [{
"vendor": "stripe",
"evidence": {
"source": "https://notify-hq.com/legal/subprocessors",
"quote": "Stripe, Inc. — payment processing and card data storage"
}
}],
"cloud_infra": [{ "vendor": "aws", "...": "..." }],
"email": [{ "vendor": "sendgrid", "...": "..." }]
},
"sends_sms": false,
"credits_used": 1,
"credit_balance": 24
}What it detects
361 vendors across 24 categories, each match backed by the quoted line it was extracted from.
How it works
Three calls from zero to structured vendor data.
- Step 01
Get a key instantly
POST your email, get an API key back in the same response. No verification click, no dashboard, no sales call. 25 free credits to start.
curl -X POST https://api.vendorstacks.com/v1/keys \ -d '{"email":"you@company.com"}' - Step 02
Check any entity
One call answers: which vendors does this entity run, across 24 categories — each match backed by the quoted source row it was extracted from.
curl "https://api.vendorstacks.com/v1/check?url=acme.com" \ -H "Authorization: Bearer $VR_KEY"
- Step 03
Reverse lookup
List entities by vendor or category. Every entity in the index that discloses a given vendor — structured pages of 10, ready for enrichment or segmentation.
curl "https://api.vendorstacks.com/v1/prospect?vendor=stripe&category=payments" \ -H "Authorization: Bearer $VR_KEY"
Use cases
One dataset, wherever your pipeline runs.
Displacement research
Find every company that discloses a competitor's product.
Enrichment pipelines
Append real vendor stacks to accounts you already track.
Agent-callable lookups
Deterministic answers your agent can cite mid-run.
Clay, n8n and Zapier
Plain JSON over HTTPS — drops into any no-code flow.
Coverage
24 vendor categories, extracted verbatim.
Every match carries the source URL and the quoted sentence it was extracted from. If it's not backed by a quoted source, it's not in the response.
Agent-first
Built to be consumed by code — human optional.
An entity-due-diligence tool your agent can call. Key issuance is a single POST, output is deterministic JSON, and paywalls are machine-readable 402s with a topup_url. Wire it in as a function-calling tool via the OpenAPI spec, markdown docs, or llms.txt.
Install instructions and the function-calling tool definition are on the skills page.
# Your agent, unsupervised: → POST /v1/keys # self-provisions a key → GET /v1/prospect?vendor=stripe&category=payments → GET /v1/company/each-prospect.com 402 Payment Required — {"topup_url": "…"} → escalates to human with exact price. Resumes on top-up.
The evidence is already public. Now it's queryable.
25 free credits — enough for 25 lookups or 250 reverse-lookup rows. No card, no verification email.
Get your API key