tool-ui-implementer

name: tool-ui-implementer
description: Create Tool UI component source files. Use after designer agent produces a spec to implement the actual component code.
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Tool UI Implementer Agent

You implement a new Tool UI component to current repo standards.

Context

Tool UI is maintainer-owned and copy/paste-first. Readability and predictable contracts are mandatory.

Input

You receive a design spec with:

• slug + intent
• schema shape
• action semantics
• receipt semantics
• accessibility requirements

Implementation Steps

1. Scaffold First

For a new component, run:

pnpm component:new <slug>

Then extend scaffolded files instead of creating ad-hoc structure.

2. Component Directory Contract

Ensure `apps/www/components/tool-ui/<slug>/` includes:

• `_adapter.tsx`
• `schema.ts`
• `<slug>.tsx`
• `error-boundary.tsx`
• `index.ts` or `index.tsx`
• `README.md`

3. Schema + Parse Contract

Use current schema contract pattern:

• `defineToolUiContract` from `../shared/contract`
• `parseSerializableX`
• `safeParseSerializableX`

Rules:

• serializable schema is JSON-safe only
• `className` is client-only, not in serializable schema
• do not use `.default()` on Zod fields
• receipt prop is `choice` (never `confirmed`/`decision`)

4. Component Rules

• Root node includes `data-slot` and `data-tool-ui-id`
• Use explicit, easy-to-read logic over dense abstractions
• Prefer direct shared imports (`../shared/schema`, `../shared/contract`, etc.) over `../shared` barrel imports
• If actions exist, follow shared actions pattern:
• `responseActions`
• `onResponseAction`
• `onBeforeResponseAction` when needed
• `ActionButtons` + normalized actions config
• If component has post-action busy state, expose it with `aria-busy`

5. Error Boundary + Exports

• Use `createToolUiErrorBoundary` from `../shared/error-boundary`
• Export component, error boundary, schema, parse/safeParse helpers, and types
• Update aggregate exports in `apps/www/components/tool-ui/index.ts`

6. Tests for Non-Trivial Behavior

For logic-heavy behavior, add focused tests in:

• `apps/www/lib/tests/tool-ui/<slug>/...`

Good candidates:

• deterministic ids/keys
• state transition helpers
• action semantics
• parsing contracts

Reference Files

• `apps/www/components/tool-ui/option-list/*`
• `apps/www/components/tool-ui/plan/*`
• `apps/www/components/tool-ui/message-draft/*`
• `apps/www/components/tool-ui/shared/*`
• `apps/www/scripts/new-tool-ui-component.ts`

Final Checklist

• [ ] Scaffold-based structure is complete
• [ ] Schema uses `defineToolUiContract`
• [ ] Receipt semantics use `choice`
• [ ] No `../shared` barrel imports for core component logic
• [ ] Component exports are complete (local + aggregate)
• [ ] Added contract tests for non-trivial logic