[Alvis1]

What

FastShaders can now run as the shader editor of another app: opened at ?embed=1 inside an iframe, it mounts a small postMessage bridge (src/embed/EmbedBridge.tsx) that talks to the parent window at the page's own origin only. The host is SuperWXR, a WebXR game engine + editor whose Material component edits its shader in an embedded FastShaders.

Messages (all type: 'superwxr:*'):

direction	message	meaning
in	superwxr:open { module, name? }	open a shader .js export — a FASTSHADERS_PROJECT_V1 block restores the graph, a bare module is parsed back — through importShaderText, the "Load Script…" path (no Open/Add dialog)
out	superwxr:ready	the bridge listens
out	superwxr:module { module, name }	the settled EXPORT module (images inlined, project block appended), whenever the graph, the module settings or the name changed — trailing-debounced like the preview, deduped on the text
out	superwxr:export { kind, fileName, mime, bytes }	what downloadShader would have downloaded: when embedded, exportShader.ts posts the bytes to the host instead of saving them

How it stays out of the way

• src/embed/embedMode.ts is the switch: a LEAF (imports nothing), sampled once at module init like eval/evalArm.ts, never true at the top level — only an embedding page can answer the bridge.
• The bridge is a lazyOr chunk mounted from App.tsx on EvalGate's terms: an ordinary visitor's boot never creates the element and never fetches the chunk (it pulls the import path and the export assembly). bootWave.test.ts still passes.
• Never in a study (isEmbedMode() && !isEvalMode()): it is a second way to change the graph.
• Messages are accepted from window.parent at location.origin only; the module is type-checked before anything runs; the name is bounded (80 chars, extension stripped) and still goes through the import path's own sanitizeDroppedName.
• The store subscription compares three references and the Output node's settings object by reference, so a drag frame costs nothing (the checklist's "selector on every notify" rule).

Tests and docs

• src/embed/embedBridge.test.ts pins the shape: the switch is a leaf and off under node, App.tsx mounts the bridge lazily behind the switch and outside a study, the bridge answers the parent at its own origin only, EXPORT posts instead of downloading only when embedded.
• npm run build (tsc -b + vite) and npm test green locally: 502 files, 11231 tests passed, 3 skipped.
• Tree entries added to CLAUDE.md and docs/dev/project-structure.md.

The host side (the panel, the superwxr:* consumer, the browser suite that drives the real embed end-to-end) lives in SuperWXR; this is the whole FastShaders half.

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Generated by Claude Code