djwt

Create and verify JSON Web Tokens with deno.

API

create

Takes a header, payload and key and returns the url-safe encoded jwt.

import { create } from "https://deno.land/x/djwt@$VERSION/mod.ts"

const jwt = await create({ alg: "HS512", typ: "JWT" }, { foo: "bar" }, "secret")
// eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIifQ.WePl7achkd0oGNB8XRF_LJwxlyiPZqpdNgdKpDboAjSTsWq-aOGNynTp8TOv8KjonFym8vwFwppXOLoLXbkIaQ

verify

Takes a jwt, key and an algorithm and returns the payload of the jwt if the jwt is valid. Otherwise it throws an Error.

import { verify } from "https://deno.land/x/djwt@$VERSION/mod.ts"

const payload = await verify(jwt, "secret", "HS512") // { foo: "bar" }

decode

Takes a jwt and returns a 3-tuple [header, payload, signature] if the jwt has a valid serialization. Otherwise it throws an Error.

import { decode } from "https://deno.land/x/djwt@$VERSION/mod.ts"

const jwt =
  "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIifQ.WePl7achkd0oGNB8XRF_LJwxlyiPZqpdNgdKpDboAjSTsWq-aOGNynTp8TOv8KjonFym8vwFwppXOLoLXbkIaQ"

const [header, payload, signature] = decode(jwt)
// [
// { alg: "HS512", typ: "JWT" },
// { foo: "bar" },
// "59e3e5eda72191dd2818d07c5d117f2c9c3197288f66aa5d36074aa436e8023493b16abe68e18dca74e9f133aff0a8e89c5c..."
// ]

getNumericDate

This helper function simplifies setting a NumericDate. It takes either a Date object or a number (in seconds) and returns the number of seconds from 1970-01-01T00:00:00Z UTC until the specified UTC date/time.

// A specific date:
getNumericDate(new Date("2025-07-01"))
// One hour from now:
getNumericDate(60 * 60)

Claims

Expiration Time (exp)

The optional exp claim in the payload identifies the expiration time on or after which the JWT must not be accepted for processing. Its value must be a number containing a NumericDate value. This module checks if the current date/time is before the expiration date/time listed in the exp claim.

const jwt = await create(header, { exp: getNumericDate(60 * 60) }, "secret")

Not Before (nbf)

The optional nbf (not before) claim identifies the time before which the jwt must not be accepted for processing. Its value must be a number containing a NumericDate value.

Algorithms

The following signature and MAC algorithms have been implemented:

• HS256 (HMAC SHA-256)
• HS512 (HMAC SHA-512)
• RS256 (RSASSA-PKCS1-v1_5 SHA-256)
• RS512 (RSASSA-PKCS1-v1_5 SHA-512)
• PS256 (RSASSA-PSS SHA-256)
• PS512 (RSASSA-PSS SHA-512)
• none (Unsecured JWTs).

Serialization

This application uses the JWS Compact Serialization only.

Specifications

• JSON Web Token
• JSON Web Signature
• JSON Web Algorithms

Contribution

Every kind of contribution to this project is highly appreciated. Please run deno fmt on the changed files before making a pull request.

Big Thank you to timreichen and all the other amazing contributors.