Effective September 2, 2026 · Version 1.0. These Terms are the agreement between you and Structural Authority LLC, a Wyoming limited liability company, doing business as Double Turnstile. Everything on this page is part of the agreement, and the Continuity page is incorporated into it. You enter this agreement when you begin enrollment, and it governs from that moment until your account is closed, except where a provision states that it survives.

What Double Turnstile is. Double Turnstile is a witness, not a guarantor. It preserves what you represented and when you represented it: exactly as entered, independently timestamped, fixed in your append-only ledger, and, when a file is involved, bound to that file’s fingerprint. It establishes provenance, attribution, contemporaneity, and integrity — nothing more.

What it is not. Double Turnstile does not establish the truth of an entry, the validity of a professional credential, the accuracy of a registry, or the correctness, prudence, or legality of a judgment. An attestation establishes what you represented and when — never that the representation was true, correct, or wise. Its evidentiary weight is determined by the forum in which it is offered, not by Double Turnstile. Nothing on this service is legal advice.

Your account. Identity assurance at enrollment binds your account to your verified identity. Every attestation is your representation, made under that identity and on your responsibility.

Your entries. Your entries are encrypted on your device before transmission. We receive and store ciphertext we cannot read and do not possess the keys required to decrypt. We can see that an entry exists and the records necessary to preserve and verify it — not what you wrote.

Your files. Files you fingerprint never leave your device. The fingerprint is computed locally. Double Turnstile receives the fingerprint, never the file. A fingerprint is not a copy of the file and cannot be used to recover its contents.

Recovery. Your vault can be opened only through an enrolled device, your Recovery Kit, or a legacy credential you create. If you lose every enrolled device and recovery credential, your encrypted entries cannot be recovered. We cannot restore what we cannot decrypt. Your export is also your independent backup.

The fee. $1,000 a year, billed annually. The first 30 days are free. Your price remains unchanged while your subscription remains continuous.

Freeze, never forfeit. If your subscription ends, your ledger closes to new entries. Nothing already recorded is forfeited. You may continue to read, export, disclose, and verify your existing entries without charge for as long as Double Turnstile operates. Your export and the published verification procedure preserve independent verification thereafter.

Continuity. Your ledger is exportable at any time. Verification is designed not to depend on Double Turnstile remaining in operation. Custody is governed by escrowed successor instructions. In an orderly wind-down, each subscriber will be given an opportunity to export their ledger before the service ends. The Continuity page describes these provisions and is incorporated into these Terms.

Lawful use. You may use Double Turnstile only for lawful purposes. Because we cannot read your entries, we cannot review their contents. You are solely responsible for what you record and for complying with the professional, contractual, confidentiality, privacy, and legal obligations that apply to you.

Legal process. We comply with valid legal process. We can produce only what we possess: encrypted ciphertext and associated records such as fingerprints, timestamps, and ledger metadata. We do not possess the keys required to decrypt your entries.

Warranties and liability. The service is provided as is. To the extent permitted by law, we disclaim implied warranties. Our aggregate liability is limited to the fees you paid Double Turnstile during the preceding twelve months.

Changes. We may revise these Terms with notice. Four commitments are foundational: what Double Turnstile establishes, what we cannot read, what you do not forfeit, and what remains independently verifiable if Double Turnstile ceases to operate. Those commitments are the constitution of the service and will not be revised.

Eligibility. You may open a ledger if you are at least eighteen years old and legally able to enter this agreement. Enrollment also requires that identity assurance succeed. Until it does, no account exists, no trial begins, and no charge is made. Double Turnstile does not verify professional credentials and does not require one — your account is bound to your verified identity, not to a license, title, or employer. One person, one ledger: an account is personal to you and may not be shared, transferred, or opened on behalf of anyone else.

The free 30 days. Your first 30 days cost nothing. Your ledger is fully open during them: you may write, attest, fingerprint files, and export. On day 31 we charge $1,000 and your first year begins. Cancel before then and you are not charged. If you cancel, or if the charge does not go through after we tell you and try again, your trial ledger is deleted. We email you first, and you may export everything you recorded before that happens. Freeze, never forfeit begins with your first paid year — what you record as a subscriber is never forfeited, and a trial that does not become a subscription is not a ledger we retain.

Automatic renewal. Your subscription renews automatically. Unless you cancel, we charge $1,000 at the end of the free 30 days and annually thereafter on the anniversary of your first charge. Your price remains at $1,000 while your subscription remains continuous. You may cancel at any time from your account settings, in the same number of steps it took to enroll — no call, email, or request to us. Cancellation stops the next charge; your ledger remains open through the term already paid for, after which Freeze, never forfeit applies. Before the first charge and each renewal, we email you the amount, charge date, and instructions for cancelling.

Refunds. The fee is not refundable. The first 30 days are free, so no one pays before deciding, and if you stop paying after your first paid year, Freeze, never forfeit applies. Three exceptions. If we end your account, we refund the unused portion of the year. If we make a material change to these Terms and you close your account rather than accept it, we refund the unused portion of the year. And if you are charged in error — twice, after cancelling, or for an account that never opened — we return the charge.

Suspension and termination. You may close your account at any time. We may suspend or end an account for nonpayment, for identity assurance obtained by fraud, for conduct that attacks or degrades the service or another person’s use of it, or where the law requires it. Because we cannot read your entries, we do not suspend or end accounts for what you record. Except for a trial that does not become a paid subscription, however your account ends — by your choice, by lapse, or by our action — Freeze, never forfeit applies: your ledger closes to new entries, nothing already recorded is forfeited, and you keep the right to read, export, disclose, and verify what is there. Ending a paid account is not a forfeiture of the ledger, and we will not treat it as one.

Acceptable use. These rules concern how you use the service, not what you record. You may not attempt to gain access to another person’s ledger, interfere with the operation or security of the service, circumvent identity assurance, use another person’s identity, resell or provide access to your account, or use the service to commit a crime. We enforce these rules from what we can observe — account behavior, technical activity, and reports from those affected. We cannot read entries and cannot review them for compliance with these rules.

Governing law and where disputes are heard. These Terms are governed by the law of the State of Wyoming, where Structural Authority LLC is organized, without regard to its conflict-of-laws rules. This does not take away the protections of consumer-protection law in the state where you live — those apply whatever this section says. Disputes arising from these Terms or your use of the service are heard in the state or federal courts located in Wyoming, and you and we each consent to their jurisdiction. If you are an individual subscriber, you may instead bring a claim in the courts of the state where you live, and we will not object to venue there.

Resolving disputes. If you have a complaint, write to us first. We will respond within thirty days. If the matter does not resolve, you are free to go to court — nothing in these Terms requires you to arbitrate, and neither of us gives up the right to a jury. Either of us may seek an injunction without waiting, where waiting would cause harm that money cannot repair. You may also bring a claim in small claims court if it qualifies, and we will not move it elsewhere.

Assignment. You may not transfer your account because it is bound to your verified identity. Your legacy credential is how access passes when it must. We may assign these Terms only to a party that takes them as they stand — including the four foundational commitments, which the acquirer may not revise — and only in a transfer that follows the escrowed successor instructions described on the Continuity page. A party that will not accept those commitments is not a party we can assign to. If the service winds down instead of transferring, every subscriber is given the opportunity to export before it ends.

Indemnification. If someone brings a claim against us because of what you recorded, how you used your ledger, or an obligation of yours we could not see — a confidentiality duty, a contract, a professional rule — you cover our reasonable costs of defending it, and we will tell you promptly and let you control the defense. This does not extend to claims arising from our own acts: our failure to keep this service running as described, to hold what we hold as described, or to comply with the law. Those are ours.

Notices. We send notices to the email address on your account, and they take effect when sent. Keep that address current — it is the only way we can reach you, and it is where renewal reminders and any notice of a change to these Terms will go. You may reach us at [support email] for anything to do with your account. Legal notices to us must go to Structural Authority LLC, [street address], and are effective on delivery.

Circumstances beyond our control. We are not responsible for delay or failure caused by events we do not control — outages at our infrastructure or timestamp providers, network failures, natural disasters, war, or acts of government. This does not excuse us from the commitments that do not depend on our performance: your entries stay encrypted and unreadable to us, your right to export is not affected, and nothing already recorded is forfeited. If a disruption prevents access for an extended period, we will tell you what happened and what we are doing about it.

Severability. If a court finds a provision of these Terms unenforceable, the rest stays in force and the provision is narrowed only as far as necessary. The four foundational commitments are an exception: they are the reason this service exists, and if any of them is held unenforceable, we will tell every subscriber plainly rather than continue as though the agreement is unchanged.

Entire agreement. These Terms, together with the Continuity page and the Privacy Policy, are the whole agreement between you and us about the service. They replace anything said elsewhere — in marketing, in conversation, or in earlier versions. If a statement anywhere else conflicts with these Terms, these Terms govern. A right we do not enforce on one occasion is not a right we have given up.

Definitions. An entry is what you write. An attestation is an entry once you have fixed it — timestamped, sealed, and added to your ledger. Your ledger is the append-only sequence of your attestations. A fingerprint is the value your device computes from a file, which identifies that file exactly without containing any part of it. Identity assurance is the verification performed at enrollment that binds your account to you. Your Recovery Kit is the credential you store yourself to reopen your vault; your legacy credential is the one you create for someone else to open it when you cannot. The four foundational commitments are the four named in Changes: what Double Turnstile establishes, what we cannot read, what you do not forfeit, and what remains independently verifiable if Double Turnstile ceases to operate.