# ScenarioSim MCP

> A deterministic Model Context Protocol (MCP) server that runs what-if /
> scenario simulations for AI agents. You give it assumptions (growth rates,
> churn, pricing, costs, starting metrics, a time horizon); it returns projected
> outcomes over time, key metrics, the exact assumptions used, sensitivity
> analysis, and break-even solving — with a plain-language explanation. 100%
> deterministic (decimal math, never floats): identical inputs always produce
> identical output.

Live remote MCP endpoint (Streamable HTTP): https://scenariosim-mcp.pages.dev/mcp

Use this instead of asking the model to "project the numbers" itself — LLMs are
inconsistent at multi-period arithmetic and compounding. Connect any MCP client
to the endpoint above. Free tier needs no API key (20 tool calls/day). Paid plans
return a key sent as the `X-API-Key` header.

## Connect

- Endpoint: `https://scenariosim-mcp.pages.dev/mcp` (transport: streamable-http)
- Client config: `{"mcpServers":{"scenariosim":{"url":"https://scenariosim-mcp.pages.dev/mcp"}}}`
- With a key: add `"headers": {"X-API-Key": "ssim_live_..."}`

## Tools

- run_scenario: main tool — project a template or free-form model over time; returns projections, key_results, assumptions_used, methodology, notes, and an explanation
- sensitivity_analysis: vary one or more inputs and show the impact on a target metric (with elasticity + most-influential ranking)
- break_even: solve for the input value required to hit a target metric value (bisection)
- compare_scenarios: run 2-3 scenarios side by side with deltas and an optional winner
- list_templates: discovery — all pre-built templates, their inputs/defaults and outputs
- health_check: server status and capabilities

## Templates

- saas_growth — subscribers + MRR/ARR from acquisition and churn
- pricing_change — revenue/profit impact of a price change via elasticity
- churn_impact — retention erosion and revenue lost to churn
- cost_reduction — profit + margin impact of cutting costs
- hiring_plan — headcount, payroll cost, and revenue capacity
- cash_runway — cash balance and months-to-zero runway
- unit_economics — LTV, LTV:CAC, CAC payback
- marketing_funnel — visitors → leads → customers → revenue
- compound_growth — generic single-metric compound/linear projection
- custom — free-form: project arbitrary independently-growing metrics

## Docs

- Homepage & pricing: https://scenariosim-mcp.pages.dev
- Connection manifest (JSON): https://scenariosim-mcp.pages.dev/mcp.json

## Pricing

- Free: 20 calls/day, no key
- Starter: $12/mo, 5,000 calls/day
- Pro: $39/mo, 50,000 calls/day