FactLens API

Browser storage

FactLens API uses browser storage and cookies for appearance, consent choices, authenticated sessions, project selection, and the public demo.

Name	Type	Purpose
`factlens-api-theme`	Local storage	Remembers light or dark appearance.
`factlens.cookie-consent.v1`	Local storage	Stores your privacy-category choices.
`factlens-api-project-v1`	Local storage	Remembers the last project selected in the dashboard.
`factlens-api-demo-history-v1`	Local storage	Stores up to 20 successful demo results on this device.
`factlens-api-demo-quota-v1`	Local storage	Caches the last demo allowance and reset display. Server-side enforcement remains authoritative.
`factlens_demo_id`	HttpOnly cookie	Anonymous browser identifier used by the public demo limiter.
Supabase authentication session	Secure cookie	Maintains dashboard sign-in for up to 30 days. The browser client uses SameSite=Lax and Secure on HTTPS. Because Supabase auth runs in the browser, this session cookie is not HttpOnly.

Public demo

The demo supports Text and Image checks. Successful results can be stored in factlens-api-demo-history-v1 and remain on this device until you clear them or clear site data.

Uploaded image bytes are not written to local history. Saved history contains result fields such as the claim, verdict, explanation, confidence, evidence strength, source links, response time, mode, and request identifier.

The server-side 10-check daily limit uses an anonymous browser identifier plus hashed network/device risk signals for abuse prevention. The locally cached quota display does not control enforcement.

Developer account

Developer sign-in uses the existing FactLens user database through Google authentication. Projects and API keys are linked to that account. New API-key secrets are shown once; FactLens stores the credential hash and limited management metadata.

The API dashboard persists the Supabase browser session in secure SameSite=Lax cookie chunks for up to 30 days and keeps automatic access-token refresh enabled. Signing out clears that stored session.

Billing

Developer API billing is separate from consumer FactLens Pro. You can manage balance and review transactions directly in Dashboard → Billing or use the API billing view at factlens.pro/billing#api. Both surfaces authenticate the same FactLens developer account and use the same project billing backend.

Paddle processes payment information under its own service and privacy terms. FactLens records transaction identifiers and project credit ledger entries needed to apply and reconcile prepaid API balance.

API request logs

Authenticated API requests are associated with a developer project and may record endpoint, request identifier, mode, status, latency, SDK name/version, request metadata, and sanitized request/response bodies for operational inspection.

Secret-like headers and fields are redacted. Uploaded audio/image base64 payloads are represented in audit logs as metadata such as presence, encoded length, and content type rather than storing full media bytes in those audit fields.

Your controls

You can clear demo history, clear site storage, revoke API keys, sign out of your developer session, and change optional privacy categories through Cookie preferences.