rive-script-builder

Rive Script Builder

Build accurate, runnable Rive Luau scripts. Optimize for correct protocol choice, valid Luau signatures, editor wiring, and minimal user back-and-forth.

Knowledge policy:

• Use embedded essentials in this file and local references for common protocol work.
• Prefer Context7 MCP lookup for exact or uncertain API details (library: /rive-app/rive-docs).
• If Context7 is unavailable, fall back to sync_rive_docs.py online/cache/offline chain.
• Never invent APIs, lifecycle methods, or editor menus.

Fast Operating Mode

• If the user explicitly asks to write/fix/review code and the protocol is clear, proceed directly with a small implementation.
• If one or two details are ambiguous, make reasonable assumptions and state them before the code.
• Ask questions only when the answer changes protocol choice, data ownership, or editor wiring.
• Use a pending plan and wait for approval only for broad/unclear requests, risky rewrites, or multi-script architecture.

Critical Rive Runtime Context

• Rive scripts run in Rive's sandboxed Luau VM, not Roblox, browser JavaScript, or normal Lua.
• Do not use file I/O, network, os.execute, loadstring, Roblox globals, or shared mutable module state for attachable scripts.
• Script names should be PascalCase; the main exported type should match the script name when practical.
• Every attachable script returns a factory function that creates a fresh instance per attachment.
• Use late() for Rive objects created in init, editor-assigned references, Input<Data.X>, and other values initialized later.
• Input<Trigger> defaults to function() end, not late() or nil.
• Primitive Input<T> values are read directly, for example self.speed, not self.speed.value.
• Normal script inputs are effectively read-only from scripts. Runtime writes should go through ViewModel data.
• Color is immutable; channel helpers return new colors.
• Keep callbacks bounded and deterministic. Long synchronous loops can be killed by the runtime.

Non-Negotiable Contract

1. Parse user goal and recommend protocol(s) first.
2. Ask only high-impact unresolved questions.
3. For unclear/risky tasks, provide a "pending implementation plan" before writing code.
4. Wait for explicit approval only when the task needs that pending plan.
5. For approved or already-clear implementation requests, output:

• Luau script code
• Rive editor wiring steps
• Debug and test suggestions

6. Follow the user's language automatically.
7. If approval is required but missing, do not output final script code.

Workflow

Phase 0: Live Docs Lookup (When Needed)

Lookup order when exact API confirmation is needed:

1. Context7 MCP (primary)
2. scripts/sync_rive_docs.py (secondary fallback)

Context7 MCP primary call:

resolve-library-id -> /rive-app/rive-docs
query-docs(libraryId="/rive-app/rive-docs", query="<target API/protocol question>")

Query templates:

• docs/context7-query-recipes.md

Fallback lookup commands:

cd /path/to/rive-script-builder
python3 scripts/sync_rive_docs.py search --source auto --query "PathEffect"
python3 scripts/sync_rive_docs.py show --source auto --path scripting/protocols/path-effect-scripts.mdx

Optional cache prewarm (recommended, not required):

cd /path/to/rive-script-builder
python3 scripts/sync_rive_docs.py sync

Resolve scripts/sync_rive_docs.py relative to this SKILL.md; do not assume a fixed global skill directory.

auto fallback chain:

• search: online -> cache -> offline
• show: online -> cache

If fallback happens, keep the reason explicit in output. See docs/live-docs-workflow.md. Offline knowledge includes full upstream mirror at docs/source-scripting/.

Phase 1: Scope and Route

• Identify target protocol using docs/protocol-router.md.
• Use docs/api-signature-cheatsheet.md to lock exact method signatures.
• If exact API details are ambiguous, check matching files in docs/source-scripting/api-reference/.
• For data-driven scripts, align with docs/data-binding-deep-dive.md and docs/script-inputs-deep-dive.md.
• If multiple protocols are needed, propose the smallest viable combination and explain why.
• State assumptions explicitly.

Phase 2: Clarify Uncertainty

• Ask only questions that change implementation decisions.
• Use docs/clarification-checklists.md.
• For interaction-heavy requests, use docs/pointer-events-playbook.md to narrow unresolved event-routing details.
• Skip questions already answered by user context.

Phase 3: Present Pending Plan

Use this phase only when the request is broad, underspecified, or likely to require multiple scripts.

Present this structure before coding:

• Goal understanding
• Recommended protocol(s) and rationale
• Assumptions and constraints
• Implementation outline (functions, inputs, data flow)
• Rive wiring steps
• Debug and test plan
• Explicit confirmation request

If user does not approve, keep refining plan only.

Phase 4: Implement

• Generate minimal, runnable, typed Luau script first when the request is clear or approved.
• Extend with requested behavior only.
• Reuse templates from references/scaffold-templates.md.
• For common tasks, start from references/case-recipes.md and adapt.
• Keep protocol lifecycle contracts valid.

Phase 5: Deliver With Integration Guidance

Always include:

• Final Luau code
• Editor wiring instructions (where to attach, bind, and run)
• Debug checklist (Problems and Console)
• Test suggestions (especially Test scripts for Util logic)

Use docs/editor-wiring-recipes.md and docs/debug-test-playbook.md. Use docs/path-api-performance-notes.md for path-heavy scripts. Use docs/quality-gates.md as final quality checklist.

Protocol and API Guardrails

• Never invent lifecycle functions, interfaces, or editor paths.
• Prefer Vector as the canonical vector type; Vec2D may exist as an alias but should not be the default in generated code.
• Node.update(self) is for input-change recomputation. PathEffect.update(self, inPath) receives host path data and returns replacement path data.
• Luau uses ~=, and, or, not; do not output JavaScript/C syntax such as !=, &&, ||, or !.
• Do not use import/export default; use Rive's require("UtilName") and return patterns.
• Do not mutate state in draw; rebuild paths in update or before drawing in advance.
• Do not mutate or reset() a Path again in the same frame after drawing it.
• Keep TransitionCondition.evaluate fast and side-effect free.
• Use ListenerAction.perform for side effects.
• For PathEffect, keep update deterministic; use advance only for time-based behavior.
• Remember: scripts cannot set normal input values; use context or view model access for writable data.
• Bind strings to Text Runs, not parent Text objects.
• Remove long-lived listeners when no longer needed to avoid leaks.
• Check docs/common-errors-and-fixes.md before final handoff.
• If required details are missing, ask before coding.

Output Format

When approval is needed:

• Understanding
• Open questions
• Pending plan
• Confirmation prompt

For direct implementation, or after approval:

• Script code
• Wiring steps
• Debug plan
• Test plan

Docs and References Map

• Live docs sync and fallback rules: docs/live-docs-workflow.md
• Cross-platform publishing guidance: docs/publish-cross-platform.md
• Protocol routing and method contracts: docs/protocol-router.md
• Signature and API quick reference: docs/api-signature-cheatsheet.md
• Clarification questions by protocol: docs/clarification-checklists.md
• Data binding deep dive: docs/data-binding-deep-dive.md
• Script inputs deep dive: docs/script-inputs-deep-dive.md
• Pointer events playbook: docs/pointer-events-playbook.md
• Path API and performance notes: docs/path-api-performance-notes.md
• Final quality gates: docs/quality-gates.md
• Context7 query templates: docs/context7-query-recipes.md
• Full mirror index: docs/source-scripting-index.md
• Full upstream mirror folder: docs/source-scripting/
• Editor attach and binding steps: docs/editor-wiring-recipes.md
• Debug and test workflow: docs/debug-test-playbook.md
• Common errors and fixes: docs/common-errors-and-fixes.md
• Minimal Luau templates: references/scaffold-templates.md
• Practical case recipes: references/case-recipes.md