Project Gumball is an MCP server with 13 tools an agent can call, among them body_metrics, color_analyse, cron_build. It answers at https://gumballtools.com/api/mcp over streamable HTTP, and it listed its tools to an anonymous client, so no sign-in was needed for that. Our probes reached it 9 of 9 times since 5 September 2026; the last check, on 17 October 2026, succeeded.
One MCP server exposing every tool in the Gumball portfolio.
Description as the publisher wrote it.
| Tool | What it does |
|---|---|
body_metrics | Compute BMI, energy expenditure, and protein targets from height and weight. Height and weight MUST carry units — a bare number is REFUSED rather than guessed, because a unit mix-up produces a plausible-looking answer that is badly wrong. R Inputs: height, weight, sex, age, activity, bodyFatPercent |
color_analyse | Convert a colour between hex, RGB, HSL, OKLCH, CMYK, and CSS names, and derive complementary, analogous, triadic, split-complementary and monochromatic harmonies. Harmonies are rotated in OKLCH, not HSL, so they keep their perceived lightne Inputs: color |
cron_build | Convert an English schedule description into a cron expression. Rule-based, not a language model: it refuses phrases outside its grammar rather than guessing, and reports which words it did not use so you can tell whether it read you correc Inputs: phrase |
cron_explain | Translate a cron expression into plain English, list upcoming run times in a timezone, and report the gotchas that make schedules misfire: day-of-month/day-of-week OR semantics, steps that do not divide evenly, impossible dates, and dayligh Inputs: expression, timezone, count |
due_date | Estimate a due date from a last menstrual period, a known conception date, an IVF transfer, or an ultrasound measurement. Gestational age is counted from the LAST PERIOD, not conception: at "6 weeks pregnant" conception was about 4 weeks ag Inputs: method, date, cycleLength, scanWeeks, scanDays, lmp |
json_to_types | Convert a JSON sample into TypeScript interfaces and a matching Zod schema. Merges EVERY array element into a union rather than typing from the first, keeps optional and nullable distinct, and emits unknown with a warning for empty containe Inputs: json, rootName |
offside | Returns a verdict plus every step taken. THREE verdicts, not two: offside, onside, and no-offside-offence — the last is real and common, because in soccer an offside POSITION is not an offence without involvement in active play. Soccer: han Inputs: sport, attacker, ball, secondLastDefender, involvement, restart |
regex_explain | Explain a regular expression in plain English and detect catastrophic backtracking. ALWAYS call this before putting a pattern where it will run against untrusted input: (a+)+$ looks harmless and takes minutes of CPU on a failing 30-characte Inputs: pattern |
round_cash_total | Settle a transaction: exact subtotal, tax computed on that exact subtotal, then round the final total to the nearest nickel — and ONLY for cash. Card, EFT and gift-card payments stay priced to the cent, so the same basket legitimately comes Inputs: subtotal, taxRatePercent, tender, rule |
rounding_impact | Compute the mean rounding delta per cash transaction across a price list. Answers "does rounding make retailers money" with arithmetic rather than a guess: symmetric rounding nets to essentially zero by construction. Pass always-up to quant Inputs: prices, taxRatePercent, rule |
timezone_convert | Convert a wall-clock time between IANA zones. Returns null when the local time DOES NOT EXIST because a daylight-saving jump skipped it, and both candidates when it happens twice. Rejects ambiguous abbreviations — most runtimes accept "BST" Inputs: time, from, to |
vocab_check | Mark an attempt and get the teaching content: whether it was right, which option was correct, why it fits, and why EVERY distractor fails. Read the distractor reasons out even when the learner was right — knowing why the tempting option was Inputs: id, choice |
vocab_draw | Draw words-in-context practice questions from a curated bank. The response deliberately contains NO answers and NO explanations, so you can quiz someone without leaking them — call vocab_check for the answer and the reason each distractor f Inputs: count, difficulty, theme, seed |
Every block below points at https://gumballtools.com/api/mcp. Pick your client and copy.
claude mcp add --transport http project-gumball https://gumballtools.com/api/mcp
{
"mcpServers": {
"project-gumball": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://gumballtools.com/api/mcp"]
}
}
}{
"mcpServers": {
"project-gumball": {
"url": "https://gumballtools.com/api/mcp"
}
}
}{
"servers": {
"project-gumball": {
"type": "http",
"url": "https://gumballtools.com/api/mcp"
}
}
}{
"context_servers": {
"project-gumball": {
"url": "https://gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"project-gumball": {
"serverUrl": "https://gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"project-gumball": {
"url": "https://gumballtools.com/api/mcp"
}
}
}name: Project Gumball
version: 0.0.1
schema: v1
mcpServers:
- name: Project Gumball
type: streamable-http
url: https://gumballtools.com/api/mcp{
"mcpServers": {
"project-gumball": {
"httpUrl": "https://gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"project-gumball": {
"type": "http",
"url": "https://gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"project-gumball": {
"url": "https://gumballtools.com/api/mcp"
}
}
}goose://extension?url=https%3A%2F%2Fgumballtools.com%2Fapi%2Fmcp&type=streamable_http&id=project-gumball&name=Project%20Gumball
It answered our last check on 17 October 2026 in 766 ms. Over 9 checks since 5 September 2026 it answered 9. Status here comes from Neuronto's own probes, not from the publisher.
Yes. It is published by gumballtools.com and served from gumballtools.com, the vendor's own domain: https://gumballtools.com/api/mcp.
13, as returned by the server's own tools/list on 5 September 2026: body_metrics, color_analyse, cron_build, cron_explain, due_date, json_to_types, offside, regex_explain, and 5 more.
It answered our last check on 17 October 2026 in 766 ms. Over 9 checks since 5 September 2026 it answered 9.
Put the server under mcpServers in ~/.cursor/mcp.json with the URL https://gumballtools.com/api/mcp. The exact JSON is above, with the same setup for Claude Code, Claude Desktop, VS Code, Windsurf, Zed, Gemini CLI and the rest.
It listed its tools to an anonymous client, so reading the tool list needs no key. Individual tools can still ask for credentials in their own inputs.
Publisher: com.gumballtools. Endpoint host: gumballtools.com. ARD identifier: urn:air:com.gumballtools:mcp:platform.
First indexed 5 September 2026. The tools are exactly what the server returned; nothing on this page
is inferred from its name. Ranking in Neuronto search is never for sale.