claude-api-in-prototypes
Call Claude from your HTML artifacts via window.claude.complete
git clone --depth 1 https://github.com/asgeirtj/system_prompts_leaks /tmp/claude-api-in-prototypes && cp -r /tmp/claude-api-in-prototypes/Anthropic/claude-design/skills/claude-api-in-prototypes ~/.claude/skills/claude-api-in-prototypesSKILL.md
# Claude API in prototypes
Your HTML artifacts can call Claude via a built-in helper. No SDK or API key needed.
```html
<script>
(async () => {
const text = await window.claude.complete("Summarize this: ...");
// or with a messages array:
const text2 = await window.claude.complete({
messages: [{ role: 'user', content: '...' }],
});
})();
</script>
```
Calls default to `claude-haiku-4-5` with a 1024-token output cap. The body may also set `model` (haiku/sonnet families only), `max_tokens` (up to 32000), `system`, `tool_choice`, and client `tools` — standard Messages API shapes, except each tool also carries `run: async (input) => string` and the helper executes tool calls in-page and loops (max 8 model calls), resolving with the final text. Handler throws become is_error tool_results. Server tools (web search etc.) are rejected; no streaming; rate-limited 15 calls/minute per user, loop iterations included. Shared artifacts run under the viewer's quota.three.js model, downloadable as OBJ or GLB
Timeline-based motion design
Runtime capabilities a published Artifact page can be granted — behavior static HTML cannot provide on its own, such as the page reading live or connected data, remembering what people do on it (a poll, a sign-up sheet, a checklist, a document edited in place — it saves new versions of itself), keeping state shared across viewers, knowing who is viewing, asking Claude a question of its own, storing files people add, or handing the viewer a file to save. Serves this user's live capability roster and the typed call definitions. Load it whenever the user asks for an artifact needing any such runtime behavior.
Design guidance and fundamentals for Artifacts.
Diagramming know-how for Artifacts - when a picture earns its place, how to draw one that shows the real mechanism, and the inline-SVG mechanics that keep it legible in both themes.
Research and plan a large-scale change, then execute it in parallel across 5–30 isolated worktree agents that each open a PR.
Automates your Chrome browser to interact with web pages - clicking elements, filling forms, capturing screenshots, reading console logs, and navigating sites. Opens pages in new tabs within your existing Chrome session. Requires site-level permissions before executing (configured in the extension).
Review the current diff, or a PR number/branch/path target, for correctness bugs and reuse/simplification/efficiency cleanups at the given effort level (low/medium: fewer, high-confidence findings; high→max: broader coverage, may include uncertain findings; ultra: deep multi-agent review in the cloud); with no level given, it reuses the level you typed last. Pass --comment to post findings as inline PR comments, or --fix to apply the findings to the working tree after the review. For ultra on a GitHub.com PR target, --post asks to post the finished review’s findings to the PR as a single comment from the user’s GitHub account (not a review; the launch dialog still confirms in interactive sessions, while non-interactive mode posts on the flag alone) and --no-post hides that option.