Imprint, privacy & contact

Operator

FreeSign is operated by Coder AI. The service at free-sign.com is offered on a best-effort, no-warranty basis. FreeSign is a proprietary, closed-source service; the security-disclosure channel at /.well-known/security.txt is public.

• Operator: Coder AI — coderai.dev.
• Contact: support@coderai.dev for general questions, partnerships, and billing. Use the contact form for one-shot questions if you prefer.
• Public docs / AI surface: llms.txt, MCP discovery, OpenAPI.
• Hosting / infrastructure: Cloudflare Workers (single Worker plus Cloudflare Static Assets) and Cloudflare D1. CA key material is hosted on Google Cloud KMS.
• Jurisdiction: the service is offered “as is”; no warranties are made about availability or legal admissibility in any specific jurisdiction.

Contact & security disclosure

The primary contact paths are the embedded form at /support and direct email to support@coderai.dev. For coordinated vulnerability disclosure, see /.well-known/security.txt.

• General questions / bugs: /support (Google Form) or support@coderai.dev.
• Security issues: follow the channel listed in security.txt; please do not disclose publicly until we've had a reasonable window to fix.
• Legal / process service: support@coderai.dev with subject line “Legal”.
• Press / interviews: support@coderai.dev with subject line “Press”.

Privacy posture

The architectural property: no PDF bytes server-side

FreeSign's central design property is that the document you sign never reaches our infrastructure. The browser hashes the PDF locally; the Worker only ever receives the 32-byte SHA-256 of the original PDF and, later, the 32-byte digest of the signature ByteRange. There is no upload route in the public API and no endpoint accepts PDF content. The MCP discovery contract advertises documentUpload: false and a public-contract test (test/public-contract.test.mjs) fails if that flag ever flips.

What the Worker does retain

The signing event is a standard signing-act audit trail. We retain:

• The OTP-verified email, stored as an envelope-scoped HMAC (we don't retain the plaintext after the OTP step).
• The signer's typed legal name (appears in the per-user leaf cert's Subject CN).
• The consent payload (canonical JSON), the OTP challenge id and verification time, and the public half of the browser-resident signing key.
• A request fingerprint — not a separate “IP column,” but a nested object folded into each audit-event row's event_data_json and hash-chained into the audit trail. It captures whatever the Cloudflare edge surfaced for that request: the connecting IP, any X-Forwarded-For chain, x-real-ip, true-client-ip, user-agent, Accept-Language, sec-ch-ua, and Cloudflare's cf geo/ASN/TLS metadata.
• An audit hash chain linking every event (envelope creation, OTP request, OTP verify, sign, seal, finalize) so tampering with one row breaks all later hashes.
• The CMS PKCS#7 seal (which embeds the leaf cert + CA cert + RFC 3161 timestamp + OpenTimestamps anchor) and the OpenTimestamps anchor row.

This is the same audit-event surface DocuSign and Adobe Sign retain for signature events. The privacy invariant is “no PDF bytes,” not “no IPs” — an evidence trail of the act of signing is the entire point of an e-signature service. See the FAQ for what a third-party verifier can independently check from the signed PDF alone (the evidence JSON is embedded inside it).

Retention

• Signed / finalized envelopes: retained indefinitely — they are the evidence. There is no document to retain, only hashes, the leaf cert, the audit chain, and the seal.
• Draft envelopes that never reached “signed” (the user dropped a PDF, requested an OTP, abandoned the flow): pruned by a daily cron after expiry (typically ≤7 days).
• OTP challenges: short-lived; expired challenges are deleted by the daily cron.
• Rate-limit buckets: 15-minute sliding window per IP and per email HMAC; old buckets are deleted by the daily cron.
• Session nonces: consumed once per request; expired nonces are deleted after the 5-minute timestamp tolerance.

Third parties involved

• Cloudflare — CDN, Workers runtime, D1 database, edge metadata. Cloudflare sees TLS-terminated request bytes (headers + JSON body), never PDF content because no PDF is ever sent to FreeSign.
• Google Cloud KMS HSM — holds the FreeSign CA private key. The HSM signs only the TBSCertificate digest of each leaf certificate; it never sees the PDF, the signature, or any PII.
• DigiCert RFC 3161 TSA (http://timestamp.digicert.com) — issues the trusted timestamp embedded in each seal. The TSA only sees the SHA-256 of the signature value, never the PDF or even the signature itself.
• OpenTimestamps public calendar pool — receives the byterange SHA-256 to create an independent timestamp proof. Calendars only see the 32-byte hash.
• Mailgun — sends OTP emails when configured. Only the OTP code and the recipient address are sent.

Terms of use

FreeSign is offered as-is to anyone who wants to sign a PDF without uploading it. There is no paid tier today and no signup, so there is no contractual relationship beyond the act of using the service.

• No warranty. The service is provided without warranty of fitness for any particular legal proceeding. We describe the ESIGN / UETA / eIDAS evidence model FreeSign is designed around (see the FAQ), but legal admissibility is always jurisdiction- and fact-specific; consult counsel if the stakes warrant it.
• No QES. FreeSign is not a Qualified Trust Service Provider and does not issue Qualified Electronic Signatures under eIDAS Article 25(2). Filings that require QES need a different tool.
• No AATL. The FreeSign CA is not on Adobe's Approved Trust List. Adobe Reader will show a yellow trust warning. The FAQ unpacks why this is a UX wart, not a verdict on the signature.
• Cert expiry. The per-user leaf certificate is issued for 10 years by default — chosen so Adobe Reader's wall-clock validation keeps the signature shown as valid across the typical “sign now, archive a decade” lifespan. After that window Reader may surface a different message; the underlying signature still verifies cryptographically and the OpenTimestamps proof and RFC 3161 timestamp still attest to the original signing time regardless of the cert window.
• No bulk-abuse use. Don't use the service for spam, phishing, or to coerce signatures from people who haven't consented. We rate-limit per-IP and per-email; serious abuse will get the IP blocked at the edge.
• Service can be discontinued. Already-signed PDFs remain verifiable without us — that's the whole point of standards-based signing. If we ever shut down, the file plus evidence JSON plus the OpenTimestamps proof still attest.

Cookies / storage

FreeSign does not set tracking cookies. Local storage in the browser is used for:

• IndexedDB session keypair (non-extractable ECDSA P-256) bound to each envelope, used to sign the envelope-scoped session signatures on every protected request. Private key never leaves the browser.
• Standard browser caches for static assets (CSS, fonts, images).

For aggregate, anonymous pageview metrics we use Cloudflare Web Analytics — a cookieless, fingerprintless beacon. It records URL, referrer, country (from the edge), and basic timing. It never sees PDF contents, form field values, OTP codes, or any signing-flow data. No other third-party trackers and no ad scripts.