In order to simplify the setup of the library, we provide the class Lcobucci\JWT\Configuration.

It's meant for:

  • Configuring the default algorithm (signer) and key(s) to be used
  • Configuring the default set of validation constraints
  • Providing custom implementation for the extension points
  • Retrieving components (encoder, decoder, parser, validator, and builder)


In order to use it, you must:

  1. Initialise the configuration object
  2. Customise the configuration object
  3. Retrieve components

Configuration initialisation

The Lcobucci\JWT\Signer\Key\InMemory object is used for symmetric/asymmetric signature.

To initialise it, you can pass the key content as a plain text:

use Lcobucci\JWT\Signer\Key\InMemory;

$key = InMemory::plainText('my-key-as-plaintext');

Provide a base64 encoded string:

use Lcobucci\JWT\Signer\Key\InMemory;

$key = InMemory::base64Encoded('YSB2ZXJ5IGxvbmcgYSB2ZXJ5IHVsdHJhIHNlY3VyZSBrZXkgZm9yIG15IGFtYXppbmcgdG9rZW5z');

Or provide a file path:

use Lcobucci\JWT\Signer\Key\InMemory;
use Lcobucci\JWT\Signer\Key\LocalFileReference;

$key = InMemory::file(__DIR__ . '/path-to-my-key-stored-in-a-file.pem'); // this reads the file and keeps its contents in memory
$key = LocalFileReference::file(__DIR__ . '/path-to-my-key-stored-in-a-file.pem'); // this just keeps a reference to file

For symmetric algorithms

Symmetric algorithms use the same key for both signature creation and verification. This means that it's really important that your key remains secret.


It is recommended that you use a key with lots of entropy, preferably generated using a cryptographically secure pseudo-random number generator (CSPRNG). You can use the CryptoKey tool to do this for you.

use Lcobucci\JWT\Configuration;
use Lcobucci\JWT\Signer\Hmac\Sha256;
use Lcobucci\JWT\Signer\Key\InMemory;

$configuration = Configuration::forSymmetricSigner(
    // You may use any HMAC variations (256, 384, and 512)
    new Sha256(),
    // replace the value below with a key of your own!
    // You may also override the JOSE encoder/decoder if needed by providing extra arguments here

For asymmetric algorithms

Asymmetric algorithms use a private key for signature creation and a public key for verification. This means that it's fine to distribute your public key. However, the private key should remain secret.

use Lcobucci\JWT\Configuration;
use Lcobucci\JWT\Signer;
use Lcobucci\JWT\Signer\Key\LocalFileReference;
use Lcobucci\JWT\Signer\Key\InMemory;

$configuration = Configuration::forAsymmetricSigner(
    // You may use RSA or ECDSA and all their variations (256, 384, and 512) and EdDSA over Curve25519
    new Signer\Rsa\Sha256(),
    LocalFileReference::file(__DIR__ . '/my-private-key.pem'),
    // You may also override the JOSE encoder/decoder if needed by providing extra arguments here


The implementation of ECDSA algorithms have a constructor dependency. Use the create() named constructor to avoid having to handle it (e.g.: Lcobucci\JWT\Signer\Ecdsa\Sha256::create()).

For no algorithm


This configuration type is NOT recommended for production environments. It's only provided to allow people to have a simpler and faster setup for tests, avoiding any kind of signature creation/verification.

use Lcobucci\JWT\Configuration;

$configuration = Configuration::forUnsecuredSigner(
    // You may also override the JOSE encoder/decoder if needed by providing extra arguments here


By using the setters of the Lcobucci\JWT\Configuration you may customise the setup of this library.


If you want to use a customised configuration, please make sure you call the setters before of invoking any getter. Otherwise, the default implementations will be used.

These are the available setters:

  • Lcobucci\JWT\Configuration#setBuilderFactory(): configures how the token builder should be created
  • Lcobucci\JWT\Configuration#setParser(): configures a custom token parser
  • Lcobucci\JWT\Configuration#setValidator(): configures a custom validator
  • Lcobucci\JWT\Configuration#setValidationConstraints(): configures the default set of validation constraints

Retrieve components

Once you've made all the necessary configuration you can pass the configuration object around your code and use the getters to retrieve the components:

These are the available getters:

  • Lcobucci\JWT\Configuration#builder(): retrieves the token builder (always creating a new instance)
  • Lcobucci\JWT\Configuration#parser(): retrieves the token parser
  • Lcobucci\JWT\Configuration#signer(): retrieves the signer
  • Lcobucci\JWT\Configuration#signingKey(): retrieves the key for signature creation
  • Lcobucci\JWT\Configuration#verificationKey(): retrieves the key for signature verification
  • Lcobucci\JWT\Configuration#validator(): retrieves the token validator
  • Lcobucci\JWT\Configuration#validationConstraints(): retrieves the default set of validation constraints