# CompoundSim Muse connector

From musedirectory.ai, the independent directory of Meta Muse connectors. Not affiliated with Meta.

## CompoundSim

Project how monthly investing or retirement withdrawals could play out, using past market returns for real assets.

- Record: https://musedirectory.ai/connector/compoundsim
- Category: Finance & Bills
- Developer: CompoundSim (https://compoundsim.app/mcp)
- Muse status: Extra setup. Not in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
- Health: Working, 266ms, checked 2026-11-01T16:31:41Z
- Endpoint: https://compoundsim.app/mcp
- Auth: No account needed; Pricing: unknown
- Screening: Screened, no issues found (2026-11-01T16:31:41Z)
- Source: Found in the official MCP Registry (app.compoundsim/compoundsim) https://registry.modelcontextprotocol.io/v0/servers?search=app.compoundsim%2Fcompoundsim

Runs compound-growth and Monte Carlo simulations on S&P 500, Nasdaq 100 and other asset mixes using past returns. Compares portfolios, estimates retirement withdrawal success rates, and returns a shareable scenario link. No account needed.

Example request: "Show me the likely range of what I'd have in 25 years if I put 500 a month into an S&P 500 index fund, adjusted for 3% inflation."

How to connect: Not in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use CompoundSim to help me. It is a free service with an MCP server at https://compoundsim.app/mcp. It does not need an API key. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.

Tools:
- simulate_portfolio: Monte Carlo simulation of investing monthly (plus an optional starting sum) in one asset or a mix rebalanced monthly. Returns the range of outcomes by year (10th to 90th percentile), the deepest fall along the way, the mix's own past return and volatility, and a compoundsim.app u
- compare_portfolios: Runs the same monthly-investing plan through 2 to 4 portfolios (the same simulation as simulate_portfolio) and returns each one's final outcome range, deepest fall, past return and volatility, and url, for questions like 'S&P 500 or all-country stocks?'.
- simulate_withdrawal: Monte Carlo simulation of withdrawing a yearly percentage of a starting balance, raised with inflation every month, from a portfolio (the 4% rule and its variants). Returns the share of paths that still had money at the end, when the others ran out, the remaining balance range in
- simulate_fixed_rate: Deterministic compound growth of monthly contributions (plus an optional starting sum) at a fixed annual return. Returns contributions, gains and total by year, and a compoundsim.app url. Use simulate_portfolio for the range of outcomes of real assets.
- get_asset_returns: Annualised past returns of the assets compoundsim simulates, over the last 5, 10 or 20 years, all the data, or a calendar span: total return with dividends reinvested, price return, the dividends' share, volatility, and the return after US inflation (in USD) or the exchange rate'

Screening checks:
- MCP handshake: pass (Answered in 266ms)
- Domain against threat feeds (Cloudflare security DNS): pass (compoundsim.app not flagged)
- Published packages against the OSV malicious-package database: n/a (No npm or PyPI package published)
- Hidden instructions or invisible characters in tool text: pass (5 tools read, nothing found)
- Inputs asking for passwords, card numbers or seed phrases: pass (None found)
- Domain and redirects: pass (No redirects off the domain)
- AI review of purpose and tool behavior: pass (No concerns)