All Tools

Calc MCP provides 21 tools for operations that AI models can struggle with. Tools are invoked by your AI assistant in response to natural language requests.

Math & Numbers

math

Evaluate mathematical expressions or compute statistics on numbers.

Security

Expressions are evaluated in a sandboxed environment. Dangerous functions like import, eval, require, process, and child_process are blocked.

Parameters:

• expression (string, optional) — Math expression to evaluate
• action (enum, optional) — eval (default) or statistics
• values (array of numbers, optional) — Array of numbers for statistics

Examples:

What's 10 + 34 × 341 ÷ 23?
→ 514.087

Calculate mean and stddev of [1, 2, 3, 4, 5]
→ { mean: 3, median: 3, stddev: 1.414, ... }

count

Count characters (grapheme-aware), words, lines, and bytes in text.

Parameters:

• text (string) — Text to analyze
• encoding (enum, optional) — utf8 (default) or shift_jis for byte count

Examples:

How many characters in "Hello, World! 🌍"?
→ 15 chars, 18 bytes

Count words in "The quick brown fox"
→ 4 words

base

Convert numbers between different bases (2–36).

Parameters:

• value (string | number) — Value to convert
• from (number) — Source base (2–36)
• to (number) — Target base (2–36)

Examples:

Convert 255 to binary
→ 11111111

Convert FF from hex to decimal
→ 255

convert

Convert between units across 8 categories: length, weight, temperature, area, volume, speed, data, time.

Parameters:

• value (number) — Value to convert
• from (string) — Source unit
• to (string) — Target unit
• category (enum, optional) — Category (auto-detected if omitted)

Supported units:

• Length: m, km, cm, mm, in, ft, yd, mi, nmi, um
• Weight: kg, g, mg, lb, oz, t, st
• Temperature: c, f, k (Celsius, Fahrenheit, Kelvin)
• Area: m2, km2, cm2, ha, acre, ft2, in2, tsubo, jo, tatami
• Volume: l, ml, m3, gal, qt, pt, cup, floz, tbsp, tsp
• Speed: m/s, km/h, mph, kn, ft/s
• Data: b, kb, mb, gb, tb, pb, bit, kbit, mbit
• Time: ms, s, min, h, d, wk, mo, yr

Examples:

100 miles in kilometers?
→ 160.93 km

72°F in Celsius?
→ 22.22°C

10 tsubo in square meters?
→ 33.06 m²

Random Generation

random

Generate cryptographically random values: UUID, ULID, password, number, or shuffle a list.

Parameters:

• type (enum) — uuid, ulid, password, number, or shuffle
• uuidVersion (enum, optional) — v4 (random, default) or v7 (time-ordered)
• length (number, optional) — Length for password (default: 16, max: 256)
• min (number, optional) — Minimum value for number (default: 0)
• max (number, optional) — Maximum value for number (default: 100)
• charset (string, optional) — Custom character set for password
• uppercase (boolean, optional) — Include uppercase letters (default: true)
• numbers (boolean, optional) — Include numbers (default: true)
• symbols (boolean, optional) — Include symbols (default: true)
• excludeChars (string, optional) — Characters to exclude (e.g., "\\|{}")
• readable (boolean, optional) — Exclude ambiguous characters (l/1/I/O/0/o)
• items (array of strings, optional) — Items to shuffle (for type=shuffle)

Examples:

Generate a UUID v7
→ 019c4b54-aad2-7e52-8a3b-...

Generate a readable 20-char password
→ hT9jZDojX6sHRJt8vaKS

Shuffle ["Alice", "Bob", "Charlie"]
→ ["Charlie", "Alice", "Bob"]

Random number between 1 and 100
→ 42

Date & Time

datetime

Get current time, convert timezones, format datetime, or work with UNIX timestamps.

Parameters:

• action (enum) — now, convert, format, or timestamp
• timezone (string, optional) — IANA timezone (e.g., Asia/Tokyo, America/New_York). Names the output zone for now/format/timestamp; for convert it is read as the source zone when fromTimezone is absent
• datetime (string, optional) — Datetime string for convert/format/timestamp. A string carrying a UTC designator or a numeric offset (2026-11-03T14:30:00Z, ...+09:00) is absolute, and fromTimezone is ignored. A bare wall-clock string (2026-11-03 14:30) is read in fromTimezone
• fromTimezone (string, optional) — IANA timezone the datetime string is written in, used when the string carries no offset of its own. Defaults to UTC, never the host's local timezone, so results do not depend on the machine the server runs on
• toTimezone (string, optional) — Target timezone for conversion
• format (string, optional) — Output format: iso, date, time, full, short, date-fns pattern (e.g. yyyy/MM/dd HH:mm), or Intl JSON options
• timestamp (number, optional) — UNIX timestamp in seconds for timestamp action

Examples:

What time is it in New York?
→ 2026-02-10T19:00:00-05:00

Convert 1609459200 to ISO8601
→ 2021-01-01T00:00:00Z

2026-11-03 14:30 in New York, in UTC?
→ 2026-11-03T19:30:00.000+00:00   (EST that day, so UTC-5)

2026-06-15 14:30 in New York, in UTC?
→ 2026-06-15T18:30:00.000+00:00   (EDT that day, so UTC-4)

date

Perform date arithmetic: difference, add/subtract, get weekday, or convert to wareki (Japanese era).

Parameters:

• action (enum) — diff, add, weekday, or wareki
• date (string) — Date string (ISO8601)
• date2 (string, optional) — Second date for diff
• amount (number, optional) — Amount to add
• unit (enum, optional) — days, months, years, hours, minutes

Examples:

What's 100 days after 2026-02-11?
→ 2026-05-22

Difference between 2026-01-01 and 2026-12-31
→ 364 days

What day of the week is 2026-02-11?
→ Wednesday (水曜日)

cron_parse

Parse cron expressions into human-readable descriptions and get next occurrences.

Parameters:

• expression (string) — Cron expression (5 fields: min hour dom mon dow). Supports weekday names (MON–SUN), month names (JAN–DEC), ranges (MON-FRI, JAN-MAR), and aliases (@daily, @hourly, @weekly, @monthly, @yearly)
• count (number, optional) — Number of next occurrences to return (default: 5)
• timezone (string, optional) — IANA timezone (default: UTC)

Examples:

When does "30 9 * * 1-5" run?
→ Mon–Fri at 9:30, next runs: ...

When does "0 9 * * MON-FRI" run?
→ Mon–Fri at 9:00

When does "0 0 1 JAN-MAR *" run?
→ 1st of Jan, Feb, Mar at midnight

Text Processing

hash

Compute hashes, checksums, or HMAC signatures: MD5, SHA-1, SHA-256, SHA-512, CRC32 (non-cryptographic checksum).

Security Notice

MD5 and SHA-1 (sha1) are cryptographically weak. Use SHA-256 or SHA-512 for security-sensitive applications.

Parameters:

• input (string) — String to hash
• algorithm (enum) — md5, sha1, sha256, sha512, or crc32 (crc32 is supported only with action=hash, not with action=hmac)
• action (enum, optional) — hash (default) or hmac
• key (string, optional) — Secret key for HMAC (required when action=hmac; HMAC is not available with crc32)

Examples:

SHA-256 hash of "password123"
→ {"hash": "ef92b778bafe771e89245b89ec..."}

HMAC-SHA256 of "message" with key "secret"
→ {"hash": "8b5f48702995c159..."}

MD5 of "hello world"
→ {"hash": "5eb63bbbe01eeed093cb22bb8f5acdc3", "warning": "MD5 is cryptographically weak..."}

base64

Encode or decode Base64 strings.

Parameters:

• input (string) — String to encode or decode
• action (enum) — encode or decode

Examples:

Base64 encode "Hello World"
→ SGVsbG8gV29ybGQ=

Base64 decode "eyJhbGciOiJIUzI1NiJ9"
→ {"alg":"HS256"}

encode

URL, HTML entity, or Unicode escape encoding/decoding.

Parameters:

• input (string) — String to encode or decode
• action (enum) — encode or decode
• type (enum) — url, html, or unicode

Examples:

URL-encode "hello world"
→ hello%20world

HTML-decode "<script>"
→ <script>

regex

Test, match, or replace with regular expressions.

Security

Patterns are analyzed for potential ReDoS (Regular Expression Denial of Service) vulnerabilities. Catastrophic backtracking patterns are detected and rejected.

Parameters:

• pattern (string) — Regular expression pattern
• flags (string, optional) — Regex flags (g, i, m, etc.)
• text (string) — Text to search
• action (enum) — match, test, replace, or matchAll
• replacement (string, optional) — Replacement string for replace

Examples:

Extract numbers from "abc123def456"
→ ["123", "456"]

Replace all spaces with dashes in "hello world"
→ "hello-world"

diff

Line diff (Myers algorithm, falls back to full replacement if edit distance exceeds 1000) or Levenshtein distance between two texts.

Parameters:

• text1 (string) — First text
• text2 (string) — Second text
• action (enum, optional) — diff (line diff, default) or distance (Levenshtein)

Examples:

Edit distance: "kitten" → "sitting"
→ 3

Line diff between two texts
→ - old line
→ + new line

char_info

Get Unicode information about characters.

Parameters:

• char (string) — Character(s) to get info about

Examples:

Unicode info for "€"
→ U+20AC, Currency Symbols

What's the code point for "🌍"?
→ U+1F30D, Miscellaneous Symbols and Pictographs

Validation & Parsing

format_validate

Validate JSON, CSV, XML, or YAML format.

Parameters:

• input (string) — String to validate/parse
• format (enum) — json, csv, xml, or yaml

Examples:

Is '{"name":"test"}' valid JSON?
→ valid, object, keys: ["name"]

Validate CSV with 3 columns
→ valid, 10 rows, 3 columns

luhn

Validate or generate Luhn check digits (credit cards, etc.).

Parameters:

• number (string) — Number string to validate or generate check digit for
• action (enum, optional) — validate (default) or generate

Examples:

Is 4539578763621486 a valid card number?
→ true

Generate check digit for 453957876362148
→ 6

semver

Semantic versioning operations: compare, validate, parse, or check range satisfaction.

Supports common npm-style range patterns: OR (||), AND (space-separated), and hyphen ranges. Other npm/semver range features may not be supported.

Parameters:

• action (enum) — compare, valid, satisfies, or parse
• version (string) — Semver version string
• version2 (string, optional) — Second version for compare
• range (string, optional) — Version range for satisfies (e.g., ^1.0.0, >=1.0.0 <2.0.0, 1.0.0 - 2.0.0)

Examples:

Does 1.5.3 satisfy ^1.0.0?
→ true

Does 1.8.0 satisfy ">=1.5.0 <2.0.0"? (AND range)
→ true

Does 2.1.0 satisfy "^1.0.0 || ^2.0.0"? (OR range)
→ true

Does 1.5.0 satisfy "1.0.0 - 2.0.0"? (hyphen range)
→ true

Compare 2.0.0 and 1.9.9
→ 2.0.0 is greater

ip

IPv4/IPv6 address information, CIDR range calculations, and membership checks.

Parameters:

• action (enum) — info, contains, or range
• ip (string, optional) — IP address. For info, IPv4 CIDR notation is also accepted
• cidr (string, optional) — CIDR notation (e.g., 192.168.1.0/24). For info, supplying an IPv4 prefix adds the network details to the result. An IPv6 prefix is rejected with a message naming the address to pass instead
• target (string, optional) — Target IP to check against CIDR

range reports both hostCount, which excludes the network and broadcast addresses, and totalAddresses, which counts every address in the block.

Examples:

IP range of 192.168.1.0/24?
→ 192.168.1.1 – .254 (254 hosts, 256 addresses)

Is 192.168.1.50 in 192.168.1.0/24?
→ true

Info on 10.0.0.0/29?
→ network 10.0.0.0, broadcast 10.0.0.7, hostCount 6, totalAddresses 8

color

Convert between color formats: HEX ↔ RGB ↔ HSL. Supports alpha channel for transparency.

Parameters:

• color (string) — Color value: #hex (3/4/6/8 digits), rgb(r,g,b), rgba(r,g,b,a), hsl(h,s%,l%), hsla(h,s%,l%,a), or named color
• to (enum, optional) — hex, rgb, or hsl (returns all if omitted)

Examples:

Convert #FF5733 to RGB
→ rgb(255, 87, 51)

Convert rgb(100, 200, 50) to HSL
→ hsl(100, 60%, 49%)

Convert #FF573380 to RGBA (8-digit HEX with alpha)
→ rgba(255, 87, 51, 0.5019607843137255)

Convert rgba(255, 0, 0, 0.5) to 8-digit HEX
→ #ff000080

jwt_decode

Decode JWT tokens (header + payload, no signature verification).

Parameters:

• token (string) — JWT token to decode

Examples:

Decode this JWT: eyJhbGci...
→ { header: { alg: "HS256" }, payload: { name: "John Doe" } }

url_parse

Parse URLs into components.

Parameters:

• url (string) — URL to parse

A query string may repeat a key, which an object cannot represent with one value per key. A key that appears once maps to a string; a key that repeats maps to an array of every value, in the order they appear. The raw search string is returned alongside.

Examples:

Parse https://example.com/search?q=hello
→ host: example.com, pathname: /search, q: "hello"

Parse https://example.com/s?tag=api&tag=mcp
→ tag: ["api", "mcp"]

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Tool Categories Summary

Category	Count	Tools
Math & Numbers	4	math, count, base, convert
Random	1	random (5 types)
Date & Time	3	datetime, date, cron_parse
Text Processing	6	hash, base64, encode, regex, diff, char_info
Validation & Parsing	7	format_validate, luhn, semver, ip, color, jwt_decode, url_parse

Total: 21 tools