Project Gumball
com.gumballtools/platformOne MCP server exposing every tool in the Gumball portfolio.
Score: 100/100
Handshake verified by our own probe.
Tools · 25
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 divi…
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…
Lists the next run times for a cron expression in a specific timezone, with no prose. Use it when the only question is "when does this next fire" — whether a job runs before a deadline, or what a user…
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 u…
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…
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 ab…
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 H…
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…
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 rig…
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 plausib…
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 p…
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 cen…
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 …
For a list price and a tax rate, finds every nearby list price that settles to the SAME cash total, and the highest one. Use it for "what should I charge" and "can I price to gain from rounding" quest…
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…
Returns the structural differences between soccer offside and hockey offside, one dimension at a time. Use it when someone asks how the two compare, and — more usefully — before reasoning about one sp…
Checks the check digit on an IBAN (ISO 7064 MOD 97-10), ISBN-10, ISBN-13, EAN-13, UPC-A, or a Luhn-checked card number. When the checksum fails it searches for the single substitution or adjacent tran…
Returns the full row-by-row schedule: per-period interest, scheduled principal, any extra principal, PMI, payment and running balance. Handles monthly or daily accrual (daily needs a start date, so le…
Converts calendar dates to ISO 8601 week-numbering dates and back, in either direction, and reports how many weeks an ISO year has. Use it whenever a date must be expressed as a week number or a week…
Validates a JSON document and reports every problem in one pass with a 1-based line and column, a stable rule code and a fix hint. Reports the three things JSON.parse cannot: duplicate keys (accepted …
Validates a YAML document, including the values that mean different things to different loaders — found by resolving each unquoted scalar under both spec versions and comparing, not by matching a list…
Validates XML for well-formedness, namespace correctness and entity-based attacks. Catches four classes of invalid XML that ordinary well-formedness checkers accept: two root elements, undeclared name…
Validates CSV against RFC 4180 and reports ragged rows individually with both field counts, because "row 4813 has 6 fields, the header has 5" is the entire answer. A ragged row loads without complaint…
Detects whether a payload is JSON, YAML, XML or CSV, then validates it. Use it for a file with no extension, a clipboard paste, or a response body with an unhelpful content type. Detection is structur…
Solves a linear or quadratic equation in one variable and returns every step: expanding parentheses, combining like terms, moving terms across the equals sign, and applying the quadratic formula with …
How to use
Claude Desktop or claude.ai: add a custom connector (Customize → Connectors; on Team and Enterprise plans an owner adds it under Organization settings → Connectors) with this server URL: https://gumballtools.com/api/mcp
Cursor or Cline: add to your MCP config:
{
"mcpServers": {
"project_gumball": {
"url": "https://gumballtools.com/api/mcp",
"transport": "streamable-http"
}
}
}