LPHACURVECONTRACT
AI reads the whole contract and points out missing clauses and internal contradictions. Once it is finalized, every signature leaves the other side evidence they cancheck for themselves, without trusting you.
The demo runs the full product on sample data. Nothing is saved to our servers.
The question procurement always asks
Procurement tends to ask a vendor three things: what if you go under? what if you alter the record? and what if the party we end up suing is you? Here are the answers — no technical vocabulary required.
The moment signing completes, the contract PDF and the evidence report are delivered to both mailboxes as real attachments — not download links. If this platform shuts down, those two files are still in your inbox.
We publish an open-source verifier: drop the evidence package in and it recomputes every item inside your own browser, offline if you like. If you would rather not use it, the package ships the commands to do the same thing with free standard tools.
Each day's signatures are folded into a single value and sent to three unrelated places, one of which is Bitcoin. Colluding would mean colluding with all of them — and one of them cannot be colluded with by anybody.
The ceiling, stated plainly: none of this makes the terms of a contract valid, and none of it proves who the signer is as a natural person. What it proves is that this document was exactly this at that point in time, and has not been altered since.
The day it goes wrong
A contract is usually taken out of the drawer at the point where nobody is being polite any more. Each line below is something the other side might say. Turn a card over to see what produces the answer — and what that particular thing fails to prove.
Hovering pauses it; a click stops it so you can read.
These limits are written into the product, not just onto this page: the evidence report marks an unanchored stretch as unanchored, and an assurance level we do not offer as not offered.
The chain of legal weight
A template tool helps you type the words. What is added here is what comes after. Scroll down, and the panel on the right changes to the screen that each link actually produces.
Proves: The content has not been changed
At finalization, SHA-256 is computed over the content itself. The full hash can be copied in one click and is printed in the “certified digital fingerprint” block on the last page of the A4 document. Anyone holding the same content and using standard tools arrives at exactly the same value.
Proves: The other side did express agreement
The other side does not register; they open a link and sign. By default they must first enter a six-digit code sent to the mailbox you specified before they can read the contract. The system records the signer's name and title, the version signed and its content hash, the source IP, the browser User-Agent, the drawn signature image, and a full-text snapshot of the consent declaration as it stood at that moment.
Proves: The content already existed at that point in time
The finalization fingerprint is submitted to an independent third-party timestamping authority. Once the .tsr is downloaded, the other side or their lawyer can verify it with openssl — without an account here, and without trusting us.
Proves: The whole history is accounted for
Creation, every saved version with that version's hash, status transitions, approvals, online signing and timestamping are strung into an append-only timeline that prints as a contract audit evidence report. The report also carries the audit hash chain and the daily aggregate, labelling each stretch anchored or unanchored and flagging automatically whether the hashes match.
$ openssl ts -verify \
-in contract.tsr -data contract.txt \
-CAfile tsa-chain.pem
Verification: OKOr drop the whole evidence .zip into the open-source verifier — every check is recomputed in your browser, and it works with the network unplugged. Open the verifier
Screens captured from the sign-up-free demo. The contracts shown are samples, not any real customer's data.
Signing and identity
Everything that happens on the signing page is recorded. When the other side says “I didn't sign that” or “I had no authority”, you have what happened at the time.
E-mail verification proves that, at the moment of signing, the other side could receive mail at the address you specified. It does not prove the natural-person identity of whoever was at the keyboard: a mailbox may be shared, forwarded, or read by an assistant. It is not equivalent to a personal certificate or to notarization.
What the AI does
Every AI output is shown to you first, and you choose whether to take it. Nothing writes itself into the contract. Hover a card — or tap it — for the detail.
Screens captured from the sign-up-free demo. The contracts shown are samples, not any real customer's data. AI-generated content must be reviewed by counsel. It is a starting point for a draft, not a document you can sign as it stands. The demo answers AI calls from a local stub, so what is shown above is the interface and the input, not model output.
The life of a contract
From drafting to archiving, a contract goes through five stages. What each one gives you, and what kind of evidence each one deposits, laid out.
Clauses, variables and the A4 layout sit on one screen. Amounts, dates and company names are entered once and flow through the whole text, and article numbers renumber themselves.
What it leaves behind: Every saved version records the time, the author and a version note, and SHA-256 is computed over that version's content.
Named reviewers approve one by one and comments attach to individual clauses. Any two versions compare line by line: additions in green, deletions in red.
What it leaves behind: Who approved, when, and with what comment all enter the audit trail. Without approval, the contract cannot be finalized.
The content locks. Changing it means un-finalizing first — and un-finalizing is itself a record. The contract PDF is rendered by the server, so both sides hold the same bytes.
What it leaves behind: The SHA-256 fingerprint computed over that version at finalization, printed in the evidence report and on the last page of the A4 document. The same fingerprint goes to a third-party timestamping authority and comes back as an RFC 3161 token.
Send the invitation link. The other side passes the code sent to the mailbox you specified, then ticks the consent declaration and signs. On completion each party receives a notification with the PDFs attached.
What it leaves behind: Invitation sent, verification passed, first opened, consent ticked and signature completed each leave a time, a source IP and a User-Agent, plus a verbatim snapshot of the consent declaration.
The whole timeline prints as an evidence report and downloads as an evidence package. That day's signatures are then aggregated into a Merkle tree whose root goes to a public log and to Bitcoin.
What it leaves behind: An append-only hash chain, an RFC 3161 timestamp, the daily Merkle root, and the publication records for Rekor and OpenTimestamps — with the report marking, stretch by stretch, what is anchored and what is not.
Drafting speed
What actually eats the time is rarely the wording. It is renumbering articles, reconciling amounts and swapping company names. All of that is automated away.
Insert a new article in the middle and everything after it shifts up on its own. No more editing “Article 7” and “Article 8” by hand.
Reorder by dragging, by keyboard, or by saying “move to article N”. Before it applies, the system lists which “see Article 8” references this reorder would repoint — numbers recompute themselves, but text written into a clause does not, and that is where the silent errors live.
The company seal is set on the organisation and stamped in the entity field; a personal seal is set by each member and stamped in the handler field, coming along automatically when that member is assigned. What is stored in the document is the snapshot at that moment, so a member later changing their seal or leaving does not affect contracts already sent out.
Text, date, number, amount, list and image. Amount variables take an ISO 4217 currency and a tax rule (percentage or fixed, added on or included), and changing the value in one place updates the whole document.
Contract variables › organisation variables › built-in own-party details, with the contract's own value winning on a name collision — one set for the whole company, overridden in place when a particular contract needs an exception.
Save a contract you have tuned as a template in one click. Next time, fill in the variable values you already know and get an editable new contract straight away.
Subtotals and totals compute live, frequently used items are saved to a catalogue for reuse, the AI can generate line items from a scope of work, and the whole thing attaches to the contract as “Attachment 1”.
The “page 2 of 3” you see in the preview is what comes out of the printer, with the company letterhead repeated on every page — no discovering at print time that the signature block was cut in half.
Tax calculation on amount variables is a documentation aid only. For an actual tax determination, consult your accountant.
Versions and collaboration
Versions, approvals and comments are all part of the audit record, and they go into the evidence report's timeline together.
Every press of “save version” leaves a version behind, and once saved it cannot be edited or deleted. The version note is what lets you recognise, six months later, what that version changed.
Added lines on green, deleted lines on red, and unchanged stretches folded to “… 12 lines unchanged …”. Which few words the other side quietly altered is visible at a glance.
Name the reviewers when sending for approval. While anyone has not approved, the “finalize” button stays grey; any one of them pressing “request changes” returns it to draft immediately.
Discussion attaches to the contract or to an individual clause and can be marked resolved but not deleted. Comments never appear on the printed document and are never seen by the external signer.
The moment a contract is finalized, the quotation attached to it refuses edits and deletion, and the “save” button disappears entirely. That is what keeps the content covered by the signature evidence from changing afterwards. To adjust it, return the contract to draft and the attachment unlocks immediately.
The account holds the whole company's contracts, so account security is part of what makes the records credible. Each member can enable two-factor login for themselves: after the password, a second step — a one-time code mailed to the account address, or an OAuth sign-in to the Google/Microsoft account matching it (your choice, with the mailed code always available as the way back). Turning it on, off, or switching methods all require re-entering the password — whoever finds a logged-in screen cannot switch it off.
The demo comes with five sample contracts in different states — including an NDA that is finalized, signed online and timestamped, whose audit trail and evidence report you can open straight away.
Sample data lives in the browser tab and is never saved to our servers. Close the tab and it is gone.