Project Scaffold

sunpeak-app/
├── src/
│   ├── resources/
│   │   └── review/
│   │       └── review.tsx                   # Review UI component + resource metadata.
│   ├── tools/
│   │   ├── review-diff.ts                   # Tool with handler, schema, and optional resource link.
│   │   ├── review-post.ts                   # Multiple tools can share one resource.
│   │   └── review.ts                        # Backend-only tool (no resource, no UI).
│   └── server.ts                            # Optional: auth, server config.
├── tests/
│   ├── simulations/
│   │   ├── review-diff.json                 # Mock state for testing (includes serverTools).
│   │   ├── review-post.json                 # Mock state for testing (includes serverTools).
│   │   └── review-purchase.json             # Mock state for testing (includes serverTools).
│   ├── e2e/
│   │   └── review.spec.ts                   # Playwright tests against the inspector.
│   └── live/
│       └── review.spec.ts                   # Live tests against real ChatGPT (one per resource).
└── package.json

// src/resources/review/review.tsx

import { useToolData } from 'sunpeak';
import type { ResourceConfig } from 'sunpeak';

export const resource: ResourceConfig = {
  description: 'Visualize and review a code change',
  _meta: { ui: { csp: { resourceDomains: ['https://cdn.example.com'] } } },
};

export function ReviewResource() {
  const { output: data } = useToolData<unknown, { title: string }>();

  return <h1>Review: {data?.title}</h1>;
}

// src/tools/review-diff.ts

import { z } from 'zod';
import type { AppToolConfig, ToolHandlerExtra } from 'sunpeak/mcp';

export const tool: AppToolConfig = {
  resource: 'review',
  title: 'Diff Review',
  description: 'Show a review dialog for a proposed code diff',
  annotations: { readOnlyHint: false },
  _meta: { ui: { visibility: ['model', 'app'] } },
};

export const schema = {
  changesetId: z.string().describe('Unique identifier for the changeset'),
  title: z.string().describe('Title describing the changes'),
};

type Args = z.infer<z.ZodObject<typeof schema>>;

export default async function (args: Args, extra: ToolHandlerExtra) {
  return { structuredContent: { title: args.title, sections: [] } };
}

// tests/simulations/review-diff.json

{
  "tool": "review-diff",                      // References src/tools/review-diff.ts
  "userMessage": "Refactor the auth module to use JWT tokens.",
  "toolInput": {
    "changesetId": "cs_789",
    "title": "Refactor Authentication Module"
  },
  "toolResult": {
    "structuredContent": {
      "title": "Refactor Authentication Module"
      // ...
    }
  }
}