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Filename Latest commit message Latest commit date
Olivier Chafik c3e9d4d694
 fix(examples): use server.registerTool for non-UI tool + fix missing imports (#173) 
* fix(threejs-server): use server.registerTool for non-UI tool

The learn_threejs tool doesn't have a UI component - it only returns
documentation text. Using registerAppTool without _meta causes a
runtime error when the function tries to access config._meta.ui.

Fixes crash: "Cannot read property 'ui' of undefined"

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* fix(examples): add missing registerAppTool and registerAppResource imports

All example servers were using registerAppTool and registerAppResource
but not importing them from @modelcontextprotocol/ext-apps/server,
causing "ReferenceError: registerAppTool is not defined" at runtime.

Affected servers:
- budget-allocator-server
- cohort-heatmap-server
- customer-segmentation-server
- scenario-modeler-server
- system-monitor-server
- threejs-server
- wiki-explorer-server

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
2025-12-17 00:17:45 +00:00
..
src Fix widget layout to use full available width 2025-12-08 14:01:28 +00:00
mcp-app.html Add color-scheme meta tag to all example apps 2025-12-15 11:42:18 -08:00
package.json feat: make MCP SDK a peer dependency (#168) 2025-12-16 22:09:59 +00:00
README.md docs: add tool visibility and restructure _meta.ui (#131) 2025-12-16 21:47:40 +00:00
server.ts fix(examples): use server.registerTool for non-UI tool + fix missing imports (#173) 2025-12-17 00:17:45 +00:00
tsconfig.json Add scenario-modeler-server example 2025-12-04 14:33:07 -06:00
vite.config.ts Add scenario-modeler-server example 2025-12-04 14:33:07 -06:00

README.md

Example: SaaS Scenario Modeler

A React-based demo MCP App that lets users adjust SaaS business parameters and see real-time 12-month projections of revenue, costs, and profitability with comparison against pre-built scenario templates.

Compare to Bootstrapped growth VC rocketship

Features

  • Interactive Parameters: 5 sliders for Starting MRR, Growth Rate, Churn Rate, Gross Margin, and Fixed Costs
  • 12-Month Projections: Line chart showing MRR, Gross Profit, and Net Profit over time
  • Scenario Templates: 5 pre-built business strategies (Bootstrapped, VC Rocketship, Cash Cow, Turnaround, Efficient Growth)
  • Template Comparison: Overlay dashed lines to compare your scenario against any template
  • Summary Metrics: Key metrics including Ending MRR, Total Revenue, Total Profit, and break-even month
  • Theme Support: Adapts to light/dark mode preferences

Running

  1. Install dependencies:

    npm install

  2. Build and start the server:

    npm run start:http  # for Streamable HTTP transport
# OR
npm run start:stdio  # for stdio transport

  3. View using the basic-host example or another MCP Apps-compatible host.

Architecture

Server (server.ts)

Exposes a single get-scenario-data tool that returns:

  • 5 pre-built scenario templates with parameters, projections, and summaries
  • Default input values for the sliders
  • Optionally computes custom projections when customInputs are provided

The tool is linked to a UI resource via _meta.ui.resourceUri.

App (src/)

  • Built with React for reactive slider updates and derived state management
  • Uses Chart.js for the line chart visualization
  • All projection calculations run client-side for instant slider feedback
  • Components: SliderRow, MetricCard, ProjectionChart
  • Template comparison shown as dashed overlay lines on the chart