Choose the singular or plural form for a given count, e.g. (apple, 3) → "apples", (apple, 1) → "apple". By default the count is prepended ("3 apples"); set includeCount=false to omit it.

Compute a cryptographic digest (SHA-2, SHA-3, BLAKE2, and legacy SHA-1/MD5/RIPEMD-160) of some data. The input may be utf8/hex/base64/base64url and the digest is returned as hex/base64/base64url.

Validate a UUID and report its version and variant.

Build braille cells from raised-dot numbers (each cell an array of 1–8). Out-of-range or repeated dots are clean 400s.

Return the synonyms of an English word, aggregated across all its senses. Optionally filter by part of speech. An unknown word returns found:false with a 200.

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

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

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).

Verify a submitted TOTP code against a base32 secret, scanning ±window time steps (default ±1) to tolerate clock drift. Returns valid plus the matching step offset (delta). A code that does not match is a successful result with valid=false — not an error.

Expand a fraction to its decimal form by exact long division, detecting a repeating cycle and rendering it in parenthesis notation (e.g. 1/6 → '0.1(6)', 1/7 → '0.(142857)'). maxDigits caps a non-repeating expansion. A zero denominator is a clean 400.

Search the constants table by key, symbol or name substring. Exact matches rank first, then prefix matches, then substring matches. Returns up to `limit` constants (default 20) plus the total match count.

Sanitize untrusted HTML to a safe allowlist. Keeps common formatting and links but removes dangerous scripting tags, inline event handlers and unsafe URL schemes. Ideal for rendering user-supplied HTML.

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

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.

Parse dice notation such as "3d6+2", "4d6kh3" (keep highest 3) or "2d20dl1" (drop lowest 1) into structured terms. Malformed notation is a clean 400.

Break a braille string into its cells and the raised-dot numbers (1–8) of each cell.

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.

Flatten a nested object/array into a single-level object whose keys are the delimited paths to each leaf (default delimiter `.`). Requires an object or array.