unjwt

name	unjwt
description	Expert knowledge for working with unjwt — a low-level, zero-dep, JWT library using the Web Crypto API. Use this skill whenever the user is working with JWS, JWE, JWK, or JWT utilities, including signing, verifying, encrypting, decrypting, key management, and session handling. Trigger on any mention of unjwt or related JWT operations.
metadata	{"version":"0.1.0","library":"unjwt","library-version":"0.7.2","org":"sandros94","documentation":"https://github.com/sandros94/unjwt"}

unjwt Skill

Low-level JWT library using the Web Crypto API. Zero runtime dependencies for core; optional peer deps for framework adapters.

Implements JWS (RFC 7515), JWE (RFC 7516), and JWK (RFC 7517).

Quick orientation

Skill written against unjwt@0.7.2. APIs are stable within v0.7 but check the changelog if behaviour seems off on a newer version.

The following is a list of reference files:

• references/jws.md: sign(), verify(), signMulti(), verifyMulti(), verifyMultiAll(), generalToFlattenedJWS(), JWSSignOptions, JWSVerifyOptions, JWSMultiSignOptions, JWSMultiVerifyOptions, JWSMultiVerifyAllOptions, JWSMultiVerifyOutcome, JWSGeneralSerialization, JWSFlattenedSerialization, JWSMultiSigner
• references/jwe.md: encrypt(), decrypt(), encryptMulti(), decryptMulti(), generalToFlattened(), JWEEncryptOptions, JWEDecryptOptions, JWEMultiEncryptOptions, JWEMultiDecryptOptions, JWEGeneralSerialization, JWEFlattenedSerialization, JWEMultiRecipient
• references/jwk.md: generateKey(), generateJWK(), importKey(), exportKey(), wrapKey(), unwrapKey(), deriveSharedSecret(), PEM import/export (importPEM, exportPEM; importFromPEM, exportToPEM are deprecated aliases), PBES2 key derivation (deriveKeyFromPassword, deriveJWKFromPassword), JWK set utilities (getJWKsFromSet, getJWKFromSet — deprecated), JWK cache (configureJWKCache, clearJWKCache, WeakMapJWKCache), key lookup types (JWKLookupFunction, JWKLookupFunctionHeader), all JWK type definitions
• references/utils.md: base64UrlEncode/base64UrlDecode, base64Encode/base64Decode, secureRandomBytes, concatUint8Arrays, textEncoder/textDecoder, type guards (isJWK, isJWKSet, isSymmetricJWK, isAsymmetricJWK, isPrivateJWK, isPublicJWK, isCryptoKey, isCryptoKeyPair, assertCryptoKey), validateJwtClaims, inferJWSAllowedAlgorithms, inferJWEAllowedAlgorithms, computeDurationInSeconds, Duration format (aliased by ExpiresIn / NotBeforeIn / MaxTokenAge), JWTClaimValidationOptions
• references/adapters-h3.md: H3 session adapters (v1 and v2), useJWESession, useJWSSession, SessionManager interface, SessionConfigJWE, SessionConfigJWS, lifecycle hooks (onRead, onUpdate, onClear, onExpire, onError), key lookup hooks (onUnsealKeyLookup, onVerifyKeyLookup), lower-level functions, cookie chunking (v2), header-based tokens, refresh token pattern
• references/adapters-elysia.md: Elysia session adapter, jwsSession/jweSession plugins, ambient ctx[contextKey], requireSession guard macro (derived per contextKey), multiple sessions (access JWS + refresh JWE), createJWSSession/createJWESession lower-level, SessionConfigJWS/SessionConfigJWE, lifecycle hooks (context not event), cookie chunking, header tokens, isolatedDeclarations plugin typing

Export Paths

Path	Purpose
unjwt	Flat barrel: all public functions and types from jws, jwe, jwk, utils
unjwt/jws	sign(), verify() (Compact) — signMulti(), verifyMulti() (General JSON Serialization)
unjwt/jwe	encrypt(), decrypt() (Compact) — encryptMulti(), decryptMulti() (General JSON Serialization)
unjwt/jwk	Key generation, import/export, wrap/unwrap, PEM conversion, PBES2, cache utils
unjwt/utils	Base64URL encode/decode, type guards, JWT claim validation, secureRandomBytes
unjwt/adapters/h3	H3 session adapter (aliases h3v1)
unjwt/adapters/h3v1	H3 v1 session adapter (Nuxt v4, Nitro v2)
unjwt/adapters/h3v2	H3 v2 session adapter (Nuxt v5, Nitro v3)
unjwt/adapters/elysia	Elysia session adapter — jwsSession/jweSession plugins (>=1.4.0)

Quick Start

// Sign and verify (JWS)
import { sign, verify } from "unjwt/jws";
import { generateJWK } from "unjwt/jwk";

const key = await generateJWK("HS256");
const token = await sign({ sub: "user123" }, key, { expiresIn: "1h" });
const { payload } = await verify(token, key);

// Encrypt and decrypt (JWE)
import { encrypt, decrypt } from "unjwt/jwe";

const jwe = await encrypt({ secret: "data" }, "password");
const { payload } = await decrypt(jwe, "password");

// H3 session
import { useJWESession } from "unjwt/adapters/h3v2";

const session = await useJWESession(event, { key: "secret", maxAge: "7D" });
await session.update({ userId: "123" });

Key Concepts

• JOSEPayload: the payload type accepted by sign/encrypt — string | Uint8Array | Record<string, unknown>; covers both JWT and generic serializable objects. JWTClaims remains the spec-compliant sub-type for typed claim access
• JWK-first key model: functions accept JWK objects directly; importKey() normalizes CryptoKey/JWK/Uint8Array/string
• Algorithm inference: sign/encrypt infer alg/enc from JWK properties when not explicitly provided; password strings default to PBES2
• dir (direct encryption): pass a CryptoKey | JWK_oct | Uint8Array directly as the CEK; enc must always be specified
• Multi-recipient JWE: encryptMulti() emits General JSON Serialization (RFC 7516 §7.2.1). One shared CEK, one ciphertext, per-recipient wraps. dir and bare ECDH-ES are rejected in multi (throw ERR_JWE_ALG_FORBIDDEN_IN_MULTI). decryptMulti() accepts General + Flattened (auto-normalized); compact tokens stay with decrypt()
• Multi-signature JWS: signMulti() emits General JSON Serialization (RFC 7515 §7.2.1). Shared payload, per-signer protected header. b64: false (RFC 7797) must be consistent across all signers. verifyMulti() returns the first valid signature; verifyMultiAll() returns per-signer outcomes for policy-driven verification (all-must-verify, M-of-N quorum, named signers). Both accept General + Flattened (auto-normalized); compact tokens stay with verify()
• ExpiresIn: time durations accept numbers (seconds) or strings: "30s", "10m", "2h", "7D", "1W", "3M", "1Y" (also long forms: "minutes", "hours", "days", "weeks", "months", "years")
• H3 Session Adapters: store JWTs in chunked cookies; sessions are lazy (id is undefined until update() is called)
• PBES2 security: default p2c (iteration count) is 600_000 per OWASP cookbook; only lower it for legacy interoperability