Record a prediction, a document, or an AI test before the result is known.
Pay 100 sats and download an OpenTimestamps proof. The stamp shows that this version existed before a later Bitcoin block. It does not show that the claim is true.
Forecasts, commitments, and uploaded files are stored here and anyone with the link can download them.
Eval files are hashed in your browser and are not uploaded. Bitcoin stores the hash, not the document.
1. Choose
Forecast, an AI test, or a document. The other tools are below that.
2. Pay 100 sats
One Lightning invoice, one stamp. If you pay and the stamp fails, do not pay again.
3. Download both
Save the file and the .ots proof. You can check them without this site.
Start here
More stamps
Developer tools
Forecast. The claim, the odds, and the resolution URL are saved on this server and are public. Use it when someone might later rewrite the prediction. Example: height reaches 1,000,000 before 1 June 2027, checked at the Blockstream tip. This does not score the forecast or pay anyone.
Eval lock. The test file and the grader are hashed in your browser. They are not uploaded. The stamp records those two hashes. Later you can tell if the files changed. It does not run the test, and it does not prove these were the files you actually used.
Prompt. The file is uploaded and anyone with the record link can download it. The stamp is one version of that file, for later comparison. It does not prove a model used the prompt.
Dataset. The file is uploaded and is public. Stamp a frozen CSV, a manifest, or an archive before the run. The stamp lets you compare versions later. It does not check quality, ownership, or that you trained on it.
Document. The file is uploaded and is public. This shows the file existed before a Bitcoin block. It does not prove who wrote it, who signed it, or that anyone agreed to it.
Commitment. The statement is stored here and is public. Name a deadline and the page a stranger can open. Nothing on this site enforces the promise or decides if you kept it.
For software. A script cannot open a bank account. It can pay a Lightning invoice. This stamps a receipt with the program’s name and what it paid for. The same call works without this page: POST /api/invoice then POST /api/machine/receipt.
Agent registration. Paying 100 sats stamps this name on this site. A thousand names cost a thousand payments. Another app is not protected unless it asks satsgate before it trusts the name. A rich attacker can still pay.
Linked timestamp. Downloading the original file and proof stays free. This creates a new public stamp that points at that record’s hash. It does not stop anyone from copying the file.
Records. Pending means the calendars have the hash and a Bitcoin block does not yet. Refresh after a few hours. Download the file and the .ots. Those two files are what you keep if this server goes away.
Pick a use above, then stamp it. Nothing is sent until you submit.
Pay 100 sats. Scan the code or copy the invoice. The stamp runs after the payment lands. If it then fails, do not pay a second time. That invoice is still unused.