Return the singular form of an English word (handles irregulars — people → person, mice → mouse).

Verify a JSON Web Token's signature and claims against a shared secret (HS*) or a PEM public key (RS/ES/PS). Returns { valid, payload } on success or { valid: false, reason } for a bad signature, expired/not-yet-active token, or a failed issuer/audience/subject check. Pass `algorithms` to pin the accepted signing algorithms and prevent algorithm-confusion attacks.

Fletcher checksum over the input payload, in 16-bit (default) or 32-bit width. Returns the checksum as an unsigned integer and hex. Non-cryptographic.

Parse a document (in any format) and re-emit it in the RFC 8785 JSON Canonicalization Scheme form — sorted keys, canonical number/string formatting — plus the SHA-256 of the canonical bytes for stable hashing, signing and dedup.

Adler-32 checksum (as used by zlib) over the input payload. Faster than CRC-32 but weaker for short inputs. Returns the checksum as an unsigned integer and 8-digit hex. Non-cryptographic.

Decode a JSON Web Token WITHOUT verifying its signature and return the header, payload and signature. A structurally malformed token is rejected before payment. Never trust a decoded payload you have not verified.

Encode a word with the Metaphone algorithm — more accurate than Soundex for English pronunciation.

Split YAML front-matter from a document — returns the parsed metadata object and the remaining content body. Malformed YAML is rejected as a clean 400.

Classify a User-Agent by device form factor and return convenience booleans (isBot, isMobile, isTablet, isDesktop, isTouchCapable) for routing decisions.

Fuzzy-search emoji by name, shortcode or keyword tag, ranked exact → prefix → substring.

Return the plural form of an English word (handles irregulars — person → people, mouse → mice).

Validate a ULID and extract its embedded timestamp and time/random components.

Validate a UUID and report its version and variant.

Estimate password strength: score, guesses, crack-time and feedback. Never stored.

Encode a word with Double Metaphone, returning a primary and a secondary code to capture alternate pronunciations (useful for non-English names).

Encode a word with the classic Soundex algorithm (letter + 3 digits) for phonetic matching of names.

Infer a JSON Schema (draft-07) from a sample document in any supported format. Types are inferred, present keys are marked required, and heterogeneous array item schemas are merged. The result validates out of the box with /v1/validate.

Given an emoji character (or any string), return its code points and — if known — its name, category, shortcodes and tags. An unknown emoji is a successful result with `known:false`, not an error.

Evaluate one or more percentiles (0–100) of a numeric sample using linear interpolation between order statistics (the R-7 / Excel PERCENTILE.INC method). 50 is the median, 25/75 the quartiles.

Generate one or more UUIDs. Supports v4 (random), v1/v7 (time), and v3/v5 (namespaced).