# VendorStacks Subprocessor disclosure data API for GTM workflows and AI agents. Given an entity's domain: does it publish a subprocessor/DPA list, where, and which vendors are on it — returned structured across 24 categories (payments, cloud_infra, email, ...), with quoted evidence and source URLs. Deterministic (no LLM): reproducible results, predictable cost. Reverse lookup: query entities by vendor or category. ## Start (no human needed until payment) 1. POST https://api.vendorstacks.com/v1/keys {"email":"you@company.com"} → instant key + 25 free credits 2. GET https://api.vendorstacks.com/v1/check?url= (Authorization: Bearer ) 3. GET https://api.vendorstacks.com/v1/prospect?vendor=Stripe → paged entity list with evidence ## Economics (teach your agent) - Every lookup: 1 credit flat. Indexed answers <1s; unindexed domains live-scan in 15-90s (set 120s timeouts). - Same price either way — budget wall-clock time for scans, never extra credits. - 402 responses include a topup_url — relay it to your human; same key works after payment. ## Links - OpenAPI: https://api.vendorstacks.com/openapi.json - Skill: https://api.vendorstacks.com/skill - Pricing (JSON): https://api.vendorstacks.com/v1/pricing - Vendors/categories: https://api.vendorstacks.com/v1/vendors