ext-apps/examples/scenario-modeler-server
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Jonathan Hefner 6eb82b5562
Refactor server startup functions
Rename `startServer` to `startStreamableHTTPServer` and add a new
`startStdioServer` helper to make the transport type explicit. Remove
the `ServerOptions` interface in favor of reading `PORT` directly from
the environment inside the function (defaulting to `3001`).

Also update Python examples to default to port `3001` for consistency.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-24 09:27:54 -06:00
..
src feat: use structuredContent with outputSchema in example servers (#220) 2026-01-12 14:25:16 +00:00
.gitignore Improve consistency and organization of examples for AI learning 2026-01-13 20:48:02 -06:00
grid-cell.png feat: add example gallery with auto-generated screenshots (#253) 2026-01-13 15:12:18 +00:00
main.ts Refactor server startup functions 2026-01-24 09:27:54 -06:00
mcp-app.html Add color-scheme meta tag to all example apps 2025-12-15 11:42:18 -08:00
package.json fix: update serve:http to run main.ts instead of server.ts (#315) 2026-01-20 17:57:08 +00:00
README.md docs: add MCP client configuration to example READMEs 2026-01-16 14:00:57 +00:00
screenshot.png feat: add example gallery with auto-generated screenshots (#253) 2026-01-13 15:12:18 +00:00
server.ts fix(examples): resolve DIST_DIR path for npm package execution (#277) 2026-01-15 12:23:13 +00:00
tsconfig.json Add scenario-modeler-server example 2025-12-04 14:33:07 -06:00
tsconfig.server.json feat: compile example servers to JavaScript for npm consumption (#259) 2026-01-14 23:46:17 +00:00
vite.config.ts Add scenario-modeler-server example 2025-12-04 14:33:07 -06:00

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

MCP Client Configuration

Add to your MCP client configuration (stdio transport):

{
  "mcpServers": {
    "scenario-modeler": {
      "command": "npx",
      "args": [
        "-y",
        "--silent",
        "--registry=https://registry.npmjs.org/",
        "@modelcontextprotocol/server-scenario-modeler",
        "--stdio"
      ]
    }
  }
}

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