x402 Utils

Compare two texts by lines, words or characters: what was added and removed, and a unified diff for lines.

Encode or decode text: base64, base64url, hex, URL (percent) encoding and HTML escaping.

Holidays of a country (and optionally a state or region) in a year, with date, name and type (public, bank, school, optional, observance), from the date-holidays data for about 200 countries.

The current time, or a given time, in one or more IANA time zones, with UTC offset, abbreviation, whether daylight saving time is in effect, and the weekday. Give a local time with from_tz to convert it, handling DST correctly.

Convert a value between units of length, mass, volume, temperature, speed, area, energy, power, pressure, data size, time and more (mathjs units), such as mi to km, degF to degC, GB to MiB, kWh to J.

Explain a cron expression in plain English and list its next run times in a time zone (5 or 6 fields, with ranges, steps, L, W and #).

Add or subtract an ISO 8601 duration (P1M, P2W, PT36H) to a date, months clamped to the month's end; or count the days, weeks, calendar months, years, seconds and business days (Monday to Friday, less a country's public holidays) between two dates. Also the weekday, ISO week and day of year.

MD5, SHA-1, SHA-256, SHA-512, SHA3-256 and Keccak-256 (Ethereum) of a text, or of bytes given as hex or base64, as hex and base64.

Generate random IDs from a cryptographic source: UUID v4, UUID v7 (time ordered), ULID or nanoid, up to 100 at a time.

Validate a JSON value against a JSON Schema (draft-07 and 2019-09 keywords, formats such as email, uri, date-time) and list every error with its path. Patterns run on RE2, so a schema cannot stall the check.

Decode a JSON Web Token's header and claims, and say when it was issued, when it expires, whether it has expired and in how many seconds it will. The signature is not verified.

Evaluate an arithmetic expression with 64 significant digits (no floating point surprises): operators, parentheses, powers, roots, logs, trigonometry, percentages, constants, units (5 inch to cm) and simple statistics.

Check whether a phone number is valid and possible, find its country and type (mobile, fixed line, toll free and others), and format it as E.164, international and national (libphonenumber metadata).

Run a regular expression on a text: every match with its position and capture groups (named too), and the text with a replacement applied. RE2 syntax, which runs in linear time (no lookaround or backreferences).

Count the tokens of a text for OpenAI models (o200k_base for GPT-4o and later, cl100k_base for GPT-4), with characters, words and lines, to size prompts and estimate cost.