JSON tier (deterministic, no LLM): verifies a claimed value lives at a named JSON path in a public endpoint's response, by independent double re-fetch. Use it for machine-readable API responses; for HTML pages use /verify. Claim keys are paths (data.items[0].price). Type-strict; volatile values return unverifiable, never a guess. Public HTTPS JSON only. First 100 checks per client are free: resend with header X-Use-Free-Allowance: yes and no payment to use them.
Checks whether a value you did not fetch yourself is actually on the page it came from. Independently re-fetches the source and returns a signed pass/fail/unverifiable verdict. A claim is never certified unless the re-fetched page contains it, and anything unconfirmed is unverifiable, never pass. Server-rendered pages only. $0.01 per check. First 100 checks per client are free: resend this exact request with header X-Use-Free-Allowance: yes and no payment to use them.
Checksum tier (deterministic, no LLM): verifies the exact bytes served at a public URL hash to a claimed sha256, by independent double re-fetch. Use it to confirm a download or artifact matches its published checksum. Bodies up to 3 MB; dynamic pages return unverifiable, never a guess. sha256 only. First 100 checks per client are free: resend with header X-Use-Free-Allowance: yes and no payment to use them.
JSON tier (deterministic, no LLM): verifies a claimed value lives at a named JSON path in a public endpoint's response, by independent double re-fetch. Use it for machine-readable API responses; for HTML pages use /verify. Claim keys are paths (data.items[0].price). Type-strict; volatile values return unverifiable, never a guess. Public HTTPS JSON only. First 100 checks per client are free: resend with header X-Use-Free-Allowance: yes and no payment to use them.
PRESENCE tier (deterministic, no LLM): confirms the claimed value appears on the live page — it does NOT confirm the value is the right answer to the question. Positive verdict is "present", never "pass"; check_type web_field_presence_v1. For full verification use /verify. First 100 checks per client are free: resend with header X-Use-Free-Allowance: yes and no payment to use them.
Redirect tier (deterministic, no LLM): verifies where a public URL actually leads: final URL (byte-exact), first response status, and hop count of the HTTP chain, walked twice with per-hop SSRF checks. Use it to confirm a link or a moved page points where it claims. Loops and unstable chains return unverifiable, never a guess. First 100 checks per client are free: resend with header X-Use-Free-Allowance: yes and no payment to use them.
XML tier (deterministic, no LLM): verifies a claimed value lives at a named path in a public XML document, by independent double re-fetch. Use it for feeds and sitemaps; for JSON use /verify-json, for HTML use /verify. Paths address elements and @attributes (urlset.url[0].loc). String-exact; ambiguous or volatile values return unverifiable, never a guess. First 100 checks per client are free: resend with header X-Use-Free-Allowance: yes and no payment to use them.
