Download src/agent/skills/shader-gen/SKILL.md from the publisher, or copy the path and open the repository. PlugMCP lists the skill and does not host the file.
Where does shader-gen live?
The publisher keeps it at https://github.com/0xsline/OpenChatCut.
Which agents can use shader-gen?
Claude, Cursor, and Codex can read a SKILL.md you add from the publisher's repository.
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name: shader-gen
description: |
AI shader generator for WebGL video effects, transitions, masks, and color grading (LUT / 调色 / 电影感 / film look). Use when the user wants a video effect (滤镜 / 特效), a transition (转场 / crossfade / wipe / cube / 3d), a mask (蒙版 / 遮罩 / reveal), a zoom / push-in (推近 / 推镜头), or a color grade — try the built-in effects (zoom, builtin LUTs) before generating a new shader.
user-invocable: true
Shader Generator
Submit-only: creates a backend generation job, returns jobId. Use the track_progress tool for job lifecycle after submission.
Always use generate.ts for new shaders. Manual authoring is only for editing existing asset code — never as a fallback when generation fails.
Catalog-first rule — try existing assets before generation
Before generating a shader, call browse_library unless the user names an exact asset id that is already visible in .
read_project
browse_library is the source of truth for built-in effects, built-in transitions, and project effect/transition assets. Built-ins are stable global asset ids, not per-project DB assets, so they may not appear in read_project asset lists.
Apply catalog entries with edit_item, do not call submit_shader.
Generate only when no catalog entry matches the user's intent closely enough.
builtin:zoom is track-bound only — DO NOT use item-bound
The default effect mode is "item-bound" (attach to a single item via targetItemId). builtin:zoom does NOT render in item-bound mode — the renderer reads zoom data exclusively from track-bound effect items. An item-bound zoom inserts into the DB silently but shows nothing in preview.
Use mode: "track-bound" with trackId + trackBoundFrom + trackBoundDurationInFrames. These three fields are required.
# Zoom on the entire video clip
edit_item(json: '{"adds":[{"type":"effect","assetId":"builtin:zoom","mode":"track-bound","trackId":"<clip-trackId>","trackBoundFrom":<clip-fromFrame>,"trackBoundDurationInFrames":<clip-durationInFrames>,"propertyOverrides":{"magnification":1.5,"shape":"hold"}}]}')
# Zoom on a sub-range of the clip (e.g. frames 90–150 only, a punch zoom on a beat)
edit_item(json: '{"adds":[{"type":"effect","assetId":"builtin:zoom","mode":"track-bound","trackId":"<trackId>","trackBoundFrom":90,"trackBoundDurationInFrames":60,"propertyOverrides":{"magnification":2,"shape":"punch"}}]}')
Get trackId / fromFrame / durationInFrames from read_project (each video/image item lists its trackId and timeline-frame range).
Key
Type
Range / values
Default
Notes
magnification
number
1–4
1.5
Zoom factor; 1 = no zoom, 2 = 2× in
focalPointX
number
0–1
0.5
Horizontal focal point (0 = left, 1 = right)
focalPointY
number
0–1
0.5
Vertical focal point (0 = top, 1 = bottom)
shape
select
punch / hold / slow-push / instant
hold
Animation curve
focalMode
select
auto / manual
auto
auto picks subject; manual uses focalPoint
easeInFrames
number
0–60
8
Frames to ramp in
easeOutFrames
number
0–60
8
Frames to ramp out
Omit propertyOverrides entirely for default zoom. Send only the keys you want to change — patch semantics.
Track-bound vs item-bound — the broader rule
Effect items in the schema have two modes:
item-bound (default): targetItemId only. Effect covers the whole target item's playback. Works for shader effects, LUTs, color grades, blurs.
track-bound: trackId + trackBoundFrom + trackBoundDurationInFrames. Effect covers a timeline range on a track, independent of any item. Required for builtin:zoom; also valid for any shader effect when you want it to cover a specific timeline range (e.g. a transition-like color shift across the boundary of two clips).
Default to item-bound for shader effects. Use track-bound when (a) the asset requires it (zoom), or (b) the effect should cover a timeline range that doesn't match a single item.
To swap: delete the effect and re-add with a different assetId. To remove: delete the effect item.
These are separate from user-uploaded .cube LUT assets (see "Applying an Existing LUT Asset" below) — those use a different code path with assetId:"lut".
Beta Status Gate
New shader generation is beta. Before generating, warn the user and wait for explicit confirmation.
Use the user's language. Chinese: "新的特效/转场生成目前还是 beta 阶段，可能会有不稳定的问题。如果你坚持要做，我可以帮你实现。" Skip if user already acknowledged in the same request.
Supported Targets
Effects and transitions apply to video, image, and gif items.
Type Routing
Before generating anything, check two non-generation paths first:
Catalog entry — use browse_library for built-in and project effects/transitions.
User-uploaded .cube LUT asset that already exists in the project library — separate code path, see "Applying an Existing LUT Asset" below. The asset shows up in read_project with type: lut.
User wants
--type
Video appearance (color, blur, glow, grain, distortion)
effect
Color grade / look (teal-orange, cinematic, vintage, LUT-style)
effect
Visibility control (mask, reveal, wipe, shape cutout, gradient fade)
effect
Blend between clips (crossfade, dissolve, slide, 3D cube/page flip)
transition
"LUT-style" in the table means generating a fresh GLSL color grade that resembles a LUT — only when the user wants something new. If they want to apply a .cube file already in the library, don't generate; bind the existing asset instead.
No separate LUT or mask generator for the generation path — those are all effect.
Applying an Existing LUT Asset
.cube files uploaded by the user become lut assets. Applying one to a clip is not generation — it's a single edit_item call that attaches an effect item whose assetId is the literal string "lut" and whose propertyOverrides.lut binds the real LUT asset id. (Legacy contract; the unified LUT API binds the LUT effect asset id directly — see edit_item description.)
assetId is the literal string "lut", not the LUT asset's id. The real LUT asset id goes inside propertyOverrides.lut.assetId.
intensity is 0–1; default 1 (full strength).
targetItemType defaults to video; also supports image, gif.
To swap a LUT on an existing effect: update propertyOverrides.lut.assetId to the new LUT asset id.
To remove: delete the effect item.
Do not call generate.ts for this path. Do not pass a real LUT asset id as assetId — the editor checks assetId === "lut" to route into the LUT renderer; passing a UUID silently renders nothing.
Usage
Before calling submit_shader, restate the user's intent in one concrete sentence, then proceed immediately. After track_progress returns, state what was produced in one line — do NOT ask "要保留还是重新生成".
Use the track_progress tool for status/wait after submission.
Generation always produces a library asset — never refuse because the timeline isn't ready.
Apply is separate and optional. Only apply when user explicitly asks ("加到视频", "apply", "用到第一段"). When ambiguous, default to library-only.
Editing Existing Properties
Any time you're about to edit shader asset.properties, applied effect/transition item.propertyOverrides, or promote a hardcoded shader value, read references/property-changes.md first.
It reinforces that shader properties is an array, but the allowed shader property types are only number, boolean, color, select, and vec2. Motion Graphic properties are also arrays, but use a different type set.
Parameters
Param
Description
Default
type
"effect" or "transition" (req'd)
—
prompt
Description of the shader (req'd)
—
name
Asset name shown in library
—
referenceAssetIds
Asset ids. Image id → model LOOKS AT it for visual inspiration. Effect/transition id → reuse its code as style anchor (≤1 per submit, kind must match type).
Requires two adjacent same-track endpoints. edit_item validates live seam feasibility and refuses durations that would require freeze frames or overlapping neighboring transitions. If the add fails, retry with the suggested durationInFrames, trim the clips to expose handles, delete/shorten neighboring transitions, or keep a hard cut.
When generating via generate.ts, the backend handles validation automatically (transpile, AST security, class structure, retry on failure).
Manual Code Verification
NEVER write shader code from scratch. Always use generate.ts for new shaders. This section is ONLY for modifying existing shader code that was already generated.
When writing shader code manually, read ${CLAUDE_SKILL_DIR}/references/design-principles.md first. If the change touches editable properties, also read ${CLAUDE_SKILL_DIR}/references/property-changes.md.
Typical workflow:
read_project with the shader assetId and code: true — read the current source.
Edit the source in your own context.
edit_asset with action=update, the same assetId, and the full replacement source inline in json.code. Validation runs automatically on update — if code is invalid, the update is rejected with error details.
How do I install shader-gen?
Download src/agent/skills/shader-gen/SKILL.md from the publisher, or copy the path and open the repository. PlugMCP lists the skill and does not host the file.
Where does shader-gen live?
The publisher keeps it at https://github.com/0xsline/OpenChatCut.
Which agents can use shader-gen?
Claude, Cursor, and Codex can read a SKILL.md you add from the publisher's repository.