compoundsim

app.compoundsimPublished by compoundsim.appOfficial publisherv1.0.0Updated Nov 1, 2026

Compound interest and Monte Carlo simulators for investing, retirement and past asset returns.

VerifiedStreamable HTTPWeb executableFinanceData & Analytics

Overview

AI-generated overview

Runs compound-interest and Monte Carlo investing simulations — monthly investing, portfolio comparisons, retirement withdrawals and past asset returns — and…

What you can do
  • Simulate monthly investing in one asset or a mix, with outcome ranges by year, worst drawdown, past return and volatility
  • Compare 2 to 4 portfolios under the same plan, e.g. one index versus all-country stocks
  • Simulate retirement withdrawals at a yearly percentage raised with inflation, showing success rate and remaining balance
  • Project deterministic compound growth of monthly contributions at a fixed annual return
  • Look up annualised past returns, volatility and inflation-adjusted returns of the simulated assets over 5, 10 or 20 years
When to use it
Useful when a user asks about long-term investing, compound interest, retirement drawdown or how one portfolio might compare with another, and wants illustrative ranges rather than a single number. Each result also comes with a link the user can open to adjust the scenario.
Requirements
Remote MCP endpoint over streamable HTTP; no package, account, API key or environment variable is declared. Amounts are entered and returned in a chosen currency (19 supported).
Before you install
Results are simulations of past data, not forecasts, and the server asks assistants to say so. Figures are illustrative only and should not be presented as investment advice. The returned links point to a third-party site.

Installation

In SourceWeft

  1. Open compoundsim in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/app.compoundsim%2Fcompoundsim/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "compoundsim": {
      "type": "http",
      "url": "https://compoundsim.app/mcp"
    }
  }
}

Tools

5

simulate_portfolio

Simulate monthly investing in a 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 url that shows the same scenario.

Parametersyearshistoryinitialmonthlyrequiredcurrencylanguageportfoliorequiredhistory_tohistory_frominflation_percent

compare_portfolios

Compare portfolios side by side

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?'.

Parametersyearshistoryinitialmonthlyrequiredcurrencylanguagehistory_toportfoliosrequiredhistory_frominflation_percent

simulate_withdrawal

Simulate spending down a portfolio in retirement

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 today's money, the success rate at withdrawal rates from 2% to 8%, and a compoundsim.app url.

Parametersyearsbalancerequiredhistorycurrencylanguageportfoliorequiredhistory_tohistory_frominflation_percentwithdrawal_rate_pct

simulate_fixed_rate

Compound interest at a 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.

Parametersyearsinitialmonthlyrequiredcurrencylanguageannual_return_pctinflation_percent

get_asset_returns

Past annualised returns of assets

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's share of the return (in another currency).

Parametersassetsperiodcurrencylanguageperiod_toperiod_from

Version history

1
  1. v1.0.0LatestNov 1, 2026

Score

72% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts

    Publish an icon in the registry entry.

  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.