html-in-canvas SKILL.md skillA
html-in-canvas from yuiseki/map-from-scratch is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add yuiseki/map-from-scratch/html-in-canvas@git:20261105.a3ec914Pins git:20261105.a3ec914 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- yuiseki/map-from-scratch
- Path
.agents/skills/html-in-canvas/SKILL.md- Versions recorded
- 1
- Latest version
- git:20261105.a3ec914, committed Nov 5, 2026
- Size
- 15,555 bytes
- Repository stars
- 24
- License
- GPL-3.0
How to draw real, interactive HTML (popups, label cards, panels with buttons, sliders and links) into a map's Canvas 2D, WebGL2 or WebGPU canvas with HTML-in-Canvas (shipped in Chrome 157), measured on the three examples in examples/htmlcanvas/. Covers the API as it actually behaves in Chrome 157, the paint-event lifecycle, hit testing (including a hit-test cache that ignores moved elements), feature detection and the DOM-overlay fallback, and how to verify all of it in this harness. Load it…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# HTML-in-Canvas: real HTML inside a map's canvas A map that wants a rich popup or a label card has always had two bad choices. A DOM overlay is real HTML, but it floats outside the canvas: it lags the camera by a frame, is missing from a canvas export, and cannot sit between two GPU layers. Drawing the card yourself (fillText, SDF text, rounded rectangles) keeps it in the canvas, but you re-implement line breaking, Japanese typography, badges and button states. HTML-in-Canvas lets the browser lay out and paint a real element that is a child of the canvas, and lets you draw that paint into 2D pixels or a GPU texture, wherever the renderer wants it. The element stays live: it takes clicks, hover, focus, text input and accessibility, at the place you tell the browser it was drawn. Everything below was measured on Chrome for Testing 157.0.8103.38 without flags, on an RTX 3060, between 2026-11-05 and 2026-11-06, in three examples: a 2D popup over aerial tiles (htmlcanvas-001) [1], WebGPU label cards (htmlcanvas-002) [2], and HTML panels standing on a WebGL2 globe (htmlcanvas-003) [3]. Numbers in brackets refer to the Sources at the end. ## Status (2026-11-06) …
Read the whole file at its exact version.
How to install
mdr add yuiseki/map-from-scratch/html-in-canvas@sha256:4b8584068d87397cThe line at the top of this page pins the label git:20261105.a3ec914, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_urtkaaoyhl6ybxkw)
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Versions
The registry has recorded 1 version of this file, committed on Nov 5, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (15555 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
yuiseki/map-from-scratch · 24 stars · license GPL-3.0 · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_urtkaaoyhl6ybxkw GET https://markdownregistry.com/api/v1/resolve?ref=yuiseki/map-from-scratch/html-in-canvas GET https://markdownregistry.com/api/v1/blob/4b8584068d87397c11095e47a034bba16ddd7747b0a928b1a5bd48e9de2e0ae9
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.