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)
• datetime (string, optional) — ISO8601 datetime string for convert/format
• fromTimezone (string, optional) — Source timezone for conversion
• 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

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
• cidr (string, optional) — CIDR notation (e.g., 192.168.1.0/24)
• target (string, optional) — Target IP to check against CIDR

Examples:

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

Is 192.168.1.50 in 192.168.1.0/24?
→ true

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

Examples:

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

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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