About Penny Rounding
Round cash totals to the nearest nickel correctly — after tax, on the total, cash only
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://penny-rounding.gumballtools.com/api/mcpclaude mcp add --transport http com-gumballtools-penny-rounding https://penny-rounding.gumballtools.com/api/mcp{"mcpServers":{"com-gumballtools-penny-rounding":{"type":"http","url":"https://penny-rounding.gumballtools.com/api/mcp"}}}Open in Cursor{"servers":{"com-gumballtools-penny-rounding":{"type":"http","url":"https://penny-rounding.gumballtools.com/api/mcp"}}}Open in VS Code{"mcpServers":{"com-gumballtools-penny-rounding":{"type":"http","url":"https://penny-rounding.gumballtools.com/api/mcp"}}}{"mcpServers":{"com-gumballtools-penny-rounding":{"serverUrl":"https://penny-rounding.gumballtools.com/api/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
Tools
3| Parameter | Type | Required | Description |
|---|---|---|---|
| rule | enum | No | symmetric (default) is the Common Cents Act and Canadian method. always-down is Indiana's rule for cash payments of TAX, not a retail rule. always-up is not law anywhere for retail and is here only to quantify it. none is what a card gets.symmetric | always-down | always-up | none |
| items | array | No | Line items, totalled in exact cents. Rounding applies to the TOTAL only. |
| tender | enum | No | Default cash. A card is NEVER rounded — if the user is paying by card, the exact total is the answer and any rounding rule is ignored.cash | card |
| subtotal | string|number | No | The pre-tax subtotal. Use this or `items`. |
| taxRatePercent | number | No | Percentage, e.g. 8.25 — not 0.0825. Supply it whenever it is known: rounding happens after tax, so the rate decides which nickel the total lands on. |
Details
The maintainer has not added details yet. Check the README in the repository.
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.