_done (underscoredone.com) — pay-per-call APIs built for AI agents. "Ask. _done."
_done matters because it fixes a category of failure that's invisible until it breaks something: an agent that "hashes" a value, resolves a domain, or checks uptime is often just generating a confident guess, and anything downstream that trusts that guess — a webhook signature, a loan calculation, a security check — silently inherits the error. By putting these deterministic tasks behind cheap, no-signup API calls, _done lets an agent get a real, verifiable answer in the same request cycle it would otherwise use to hallucinate one, without a developer having to stand up infrastructure, manage credentials, or onboard to a vendor for a single function call.
Key features:
No accounts, keys, or subscriptions — pay per call in USDC via x402 (HTTP 402) Works on Base and Solana mainnet Flat pricing, no tiers Every API independently specced with agent-readable OpenAPI metadata (x-ai-instructions, x-guidance) ~1-cent response time under 2s
Use cases:
Verifying webhooks/signatures an LLM can't hash correctly DNS/WHOIS/domain age checks before an agent acts on a domain DMARC/BIMI/ASN lookups for security or deliverability workflows Uptime/HTTP status checks before an agent trusts a live endpoint Mortgage amortization, QR generation, OCR, screenshots — deterministic tasks LLMs fake Port scanning, sitemap/SEO extraction for agent-driven research tools
Pricing:
$0.01 per call, flat, across every API — no subscriptions, no overage Pay via signed USDC transaction (x402), no login required
