# Create and update Figma shaders

Load this skill before every `create_shader` or `update_shader` call. It covers account-library shader authoring through the Figma MCP server. Reading or applying an existing shader does not require this skill.

Shaders have two kinds:

- `effect` samples and transforms the rendered layer beneath it. Use it for blur, distortion, glow, color grading, pixelation, halftone, or other post-processing.
- `fill` generates pixels without an input raster. Use it for gradients, patterns, noise, textures, and procedural backgrounds.

Do not silently switch kinds during an update. The `kind` passed to `update_shader` must match the existing shader.

## Create workflow

1. Decide whether the request is an effect or fill. Ask only when the visual intent does not resolve the distinction.
2. Resolve `planKey`. Reuse one supplied by the user; otherwise call `whoami`. Use the sole eligible plan automatically, or ask the user to choose when several materially different plans are available.
3. Call `create_shader` once with a concise name, description, selected `kind`, and `planKey`. This creates a starter scaffold, not the requested final shader.
4. Call `get_shader` with the returned `id`, then read every source URI. If the client cannot read MCP resources, call `get_shader` with `includeSource: true` instead. This establishes the runtime imports and the scaffold's fixed metadata contract.
5. Author the complete replacement `main.ts` for the requested result.
6. Call `update_shader` with the returned `id`, the same `kind`, `files: [{ path: "main.ts", content: "..." }]`, and a specific `commitMessage`. Use `metadata` when changing the name, description, or animation capabilities. Set `metadata.isAnimated: true` when the source reads time-related frame inputs and `metadata.usesMouse: true` when it reads `frame.mousePosition`.

Never stop after `create_shader`: the starter scaffold is only a structural starting point.

## Update workflow

1. Identify the shader with `list_shaders`, then call `get_shader`. Use its `type` (`effect` or `fill`) as the required update kind.
2. Read every source URI returned by `get_shader` before editing. If the client cannot read MCP resources, call it with `includeSource: true`. Treat those files as the current source of truth.
3. Preserve existing controls and behavior unless the user asks to change them.
4. Call `update_shader` with the complete replacement `main.ts` in the `files` array, not a diff or partial fragment. An empty `files` array is valid only for a metadata-only update.

## Authoring rules

- Before writing the `main.ts` replacement, read [Shader source authoring](references/authoring.md). It contains the required module shape, WebGPU lifecycle, supported parameter schemas, effect/fill alpha rules, and WGSL failure checklist.
- Match animation metadata to the source. Set `metadata.isAnimated: true` if `main.ts` reads `frame.time`, `frame.deltaTime`, or `frame.frame`, and set `metadata.usesMouse: true` if it reads `frame.mousePosition`. Set the corresponding value to `false` when removing the last such use. `update_shader` applies these metadata fields to the fixed `features.json` manifest even though that file cannot be replaced directly.
- Prefer `frame.time` for animation so skipped frames do not change the result. It is an absolute millisecond clock; convert it to seconds with `Number(frame.time) * 0.001` when useful.
- Expose controls for values users are likely to tune per layer; hardcode implementation details.
- Keep numeric ranges bounded and defaults visually useful.
- For effects, sample the input raster intentionally. For fills, do not assume an input raster exists.
- Treat a non-error `update_shader` result as success. Record the returned version when present; a successful response may omit it.
- On a build error, use the returned compiler output to make the smallest source correction and retry once. If it still fails, surface the error instead of repeatedly rewriting the shader.
- If the tool reports that animation or mouse input is unavailable, treat that as a terminal capability gate: do not retry or attempt to bypass it. Offer to author a static shader whose exposed properties can be keyframed in Motion mode instead.

## Completion

Report the shader name, kind, and id, plus the returned version when present. Briefly identify the controls or behavior that were added. Construct and include a clickable URL that opens a new Design file with the unpublished shader ready to try, using the exact shader id as `try-tool-resource-content-id`. Set `try-tool-resource-type` from the shader kind: `gen_effect` for an effect and `gen_fill` for a fill.

`https://www.figma.com/file/new?try-tool-resource-content-id=<id>&try-tool-resource-type=<gen_effect|gen_fill>&type=design&mode=design`

After presenting the new-file link, ask whether the user wants to open the shader in an existing Figma Design file instead. If yes, reuse a file URL already provi

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