Filling the PASETO gap in JavaScript: paseto-kit (v3/v4 + full PASERK)

The gap PASETO is a "secure alternative to JWT" — no algorithm-confusion footguns, versioned protocols, sensible defaults. On Node, the reference implementation was panva/paseto. In March 2025 it was archived read-only. The maintained libraries that remain are v4-only and don't implement PASERK — the companion standard for serializing, wrapping, and sealing keys. So there was no maintained JS library that covered both PASETO and full PASERK. That's the gap paseto-kit fills. What's in it PASETO v4 — XChaCha20 + BLAKE2b (local), Ed25519 (public) PASETO v3 — the NIST/FIPS-friendly profile: P-384 / AES-256-CTR / HMAC-SHA384 Full PASERK (all 11 types, per version): local/public/secret serialization, lid/pid/sid key IDs, local-wrap/secret-wrap, password wrapping with Argon2id (v4) and PBKDF2 (v3), and seal (X25519 / P-384 ECDH) Registered-claims validation (exp, nbf, iss, aud, sub) with clock tolerance Runtime-agnostic — one build for Node, Deno, Bun, browsers, edge. No node: imports, no Buffer; just Uint8Array + WebCrypto's CSPRNG, on the audited @noble/* primitives Using it import { generateKeyPair, sign, verify } from 'paseto-kit'; const { secretKey, publicKey } = generateKeyPair(); const token = sign(secretKey, { role: 'admin' }); const { payload } = verify(publicKey, token); Need the NIST profile? Everything's mirrored under a v3 namespace, with distinct key types so a v4 key can never be used on a v3 token: import { v3 } from 'paseto-kit'; const key = v3.generateLocalKey(); v3.decrypt(key, v3.encrypt(key, { sub: 'u1' }), { validate: { exp: true } }); On correctness Crypto libraries earn trust by being boring and verifiable. paseto-kit implements no novel cryptography — it assembles audited primitives per spec, and it's tested against the official PASETO and PASERK test vectors, including the expect-fail cases (e.g. non-canonical base64url, which must be rejected to prevent token malleability). Honest caveat: it's pre-1.0 and has not had an independent third-party security audit. Review it before production use, and file issues — especially on the crypto. npm: npm install paseto-kit · repo: https://github.com/Elalitareq/paseto-kit