PointCast Script
An original face drawn for this studio. Glyphs live in scripts/signature/glyphs.mjs.
Copyright 2026 PointCast, with Reserved Font Name “PointCast Script”.
Front Door · block 0765 · devnet · no value · may reset
Signature Studio
Make a mark. Export it. Hash it. Sign a sentence with a key your browser makes. If you want a time on one public server, record the hash on the PointCast devnet.
- Make a mark
- Export
- Fonts
- What “valid” means
- Sign and check
- Record on the devnet
- History of signatures
01 · The mark stays in your browser until you export or record
Make a mark
Draw with a mouse or a finger. Fast strokes get thinner. A pen that reports pressure is used when the pressure actually changes. Ink and the flourish above apply to the drawing too.
PNG, JPEG, GIF, or WebP. The studio wraps the picture in an SVG. It does not trace it into paths.
Typed and drawn marks are vector paths. An upload stays a picture.
02 · Files you can keep
Export
The email HTML points at a file named signature.png. Attach that PNG. Most mail clients strip an image pasted as a data URI. The inline SVG is a bonus, and webmail may remove it.
03 · Open licenses, and one face of our own
The faces
Outlines are extracted ahead of time, so the page draws paths without loading a font file. The font files are still here, with their licenses. How to add a face or a glyph.
Dancing Script
SIL Open Font License. The file is a variable font. These outlines are the regular master, weight 400.
Copyright 2016 The Dancing Script Project Authors, with Reserved Font Name “Dancing Script”.
Great Vibes
SIL Open Font License. Regular.
Copyright 2015 The Great Vibes Pro Project Authors.
Allura
SIL Open Font License. Regular.
Copyright 2010 The Allura Project Authors.
Sacramento
SIL Open Font License. Regular.
Copyright 2012 Brian J. Bonislawsky DBA Astigmatic, with Reserved Font Name “Sacramento”.
Mrs Saint Delafield
SIL Open Font License. Regular.
Copyright 2011 Alejandro Paul, with Reserved Font Name “Mrs Saint Delafield”.
Herr Von Muellerhoff
SIL Open Font License. Regular.
Copyright 2011 Alejandro Paul, with Reserved Font Name “Herr Von Muellerhoff”.
Homemade Apple
Apache License 2.0, not the SIL Open Font License. The LICENSE.txt beside the file is the grant.
Copyright 2010 Font Diner, Inc.
04 · Five different jobs, often called by one word
What “validating” a signature can mean
A mark
Shows a shape someone made or chose: typed in a font, drawn, or uploaded.
Integrity
A SHA-256 of the exported PNG. If one byte of that file changes, the hash changes. It does not say who made the file.
A key
An ed25519 signature over a statement and that hash. It shows the holder of a private key signed those exact bytes. It does not show who that person is.
A time on one server
A signed post on the PointCast devnet is sealed into a block with that server’s clock. devnet · no value · may reset. It is not a legal timestamp and it is not anchored to another chain.
A legal signature
Statutes such as the US ESIGN Act and UETA can give effect to an electronic signature when intent, agreement, attribution and retention are met. This page does not do those things. It is not a notary and not an e-signature service.
The longer version, with the sources, is the history of signatures.
05 · A fingerprint, then a key
Hash it, sign a statement, or check someone else’s
The hash is SHA-256 of the exported PNG bytes. The signature is ed25519 over a short canonical text: a header, that hash, and your statement. Anyone can paste the three pieces below and check them. The private key stays in this browser.
A key, in this browser
This key is separate from the chain apps. “Keep it on this device” writes the seed to localStorage. Any script on pointcast.xyz can read that. It is a play key. Do not reuse it anywhere that matters. Leave the box unchecked and the key dies with the tab. Nothing here stores a private key on a server.
Reading whether this browser can make an ed25519 key.
Check a signature
Paste the canonical text, the 64-character public key, and the 128-character signature. Changing one character of the statement makes the check fail.
06 · devnet · no value · may reset
Record the hash on the PointCast devnet
Prepare builds a signature/v1 post and shows it here before anything is sent. Sign and send uses the key above. The post goes to channel ART, which the house holds open. The body names the PNG’s SHA-256. The chain docs describe a 64 KiB body. On 2026-10-20 the public devnet rejected a body over 8,192 bytes, and a larger request at 17,408 bytes of JSON. It also refused a real outline: its word filter folds digits into letters and then reads the coordinates as text. The recorded post therefore keeps the hash and says svg:omitted. Download the SVG here. A media URI is included only if you supply an https, ipfs, or ar address. This studio does not host images.
Reading the public devnet.
Why this is a post, not a mint
An edition mint on this devnet is a different transaction from a post. edition_mint carries a recipe and an approval signature from the edition’s attestor. The public devnet’s editions list, GET /editions, currently has one edition, daily-mint, and its mints are approved by the house attestor. Signature Studio cannot produce that approval, and it will not pretend a post is a mint. To mint a signature as an edition you would need: an open_edition from the editions admin whose recipe is short enough for the chain (the PNG’s SHA-256, or a small SVG), either no attestor or an attestor that will sign approval_digest for the visitor’s key, and a renderer hash the terms commit to. Until that edition exists, Record writes a signature/v1 post on the ART channel, which the house holds open.
Editions load with the devnet status.
