diff --git a/src/Component/Checker/CallableChecker.php b/src/Component/Checker/CallableChecker.php
new file mode 100644
index 00000000..3bb63735
--- /dev/null
+++ b/src/Component/Checker/CallableChecker.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Jose\Component\Checker;
+
+use function call_user_func;
+use InvalidArgumentException;
+use function is_callable;
+
+/**
+ * @see \Jose\Tests\Component\Checker\CallableCheckerTest
+ */
+final class CallableChecker implements ClaimChecker, HeaderChecker
+{
+    /**
+     * @param string     $key      The claim or header parameter name to check.
+     * @param callable(mixed $value): bool $callable The callable function that will be invoked.
+     */
+    public function __construct(
+        private readonly string $key,
+        private $callable,
+        private readonly bool $protectedHeaderOnly = true
+    ) {
+        if (! is_callable($this->callable)) { // @phpstan-ignore-line
+            throw new InvalidArgumentException('The $callable argument must be a callable.');
+        }
+    }
+
+    public function checkClaim(mixed $value): void
+    {
+        if (call_user_func($this->callable, $value) !== true) {
+            throw new InvalidClaimException(sprintf('The "%s" claim is invalid.', $this->key), $this->key, $value);
+        }
+    }
+
+    public function supportedClaim(): string
+    {
+        return $this->key;
+    }
+
+    public function checkHeader(mixed $value): void
+    {
+        if (call_user_func($this->callable, $value) !== true) {
+            throw new InvalidHeaderException(sprintf('The "%s" header is invalid.', $this->key), $this->key, $value);
+        }
+    }
+
+    public function supportedHeader(): string
+    {
+        return $this->key;
+    }
+
+    public function protectedHeaderOnly(): bool
+    {
+        return $this->protectedHeaderOnly;
+    }
+}
diff --git a/src/Component/Checker/IsEqualChecker.php b/src/Component/Checker/IsEqualChecker.php
new file mode 100644
index 00000000..d826475c
--- /dev/null
+++ b/src/Component/Checker/IsEqualChecker.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Jose\Component\Checker;
+
+/**
+ * @see \Jose\Tests\Component\Checker\IsEqualCheckerTest
+ */
+final class IsEqualChecker implements ClaimChecker, HeaderChecker
+{
+    /**
+     * @param string $key                 The claim or header parameter name to check.
+     * @param mixed  $value               The expected value.
+     * @param bool   $protectedHeaderOnly [optional] Whether the header parameter MUST be protected.
+     *                                    This option has no effect for claim checkers.
+     */
+    public function __construct(
+        private readonly string $key,
+        private readonly mixed $value,
+        private readonly bool $protectedHeaderOnly = true
+    ) {
+    }
+
+    public function checkClaim(mixed $value): void
+    {
+        if ($value !== $this->value) {
+            throw new InvalidClaimException(sprintf('The "%s" claim is invalid.', $this->key), $this->key, $value);
+        }
+    }
+
+    public function supportedClaim(): string
+    {
+        return $this->key;
+    }
+
+    public function checkHeader(mixed $value): void
+    {
+        if ($value !== $this->value) {
+            throw new InvalidHeaderException(sprintf('The "%s" header is invalid.', $this->key), $this->key, $value);
+        }
+    }
+
+    public function supportedHeader(): string
+    {
+        return $this->key;
+    }
+
+    public function protectedHeaderOnly(): bool
+    {
+        return $this->protectedHeaderOnly;
+    }
+}
diff --git a/tests/Component/Checker/CallableCheckerTest.php b/tests/Component/Checker/CallableCheckerTest.php
new file mode 100644
index 00000000..d90c89de
--- /dev/null
+++ b/tests/Component/Checker/CallableCheckerTest.php
@@ -0,0 +1,88 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Jose\Tests\Component\Checker;
+
+use InvalidArgumentException;
+use Jose\Component\Checker\CallableChecker;
+use Jose\Component\Checker\InvalidClaimException;
+use Jose\Component\Checker\InvalidHeaderException;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @internal
+ */
+final class CallableCheckerTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function theCallableIsCallable(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('The $callable argument must be a callable.');
+
+        new CallableChecker('foo', 'not_a_callable');
+    }
+
+    /**
+     * @test
+     */
+    public function theCallableDoesNotReturnABoolean(): void
+    {
+        $this->expectException(InvalidClaimException::class);
+
+        $checker = new CallableChecker('foo', fn (mixed $value) => 1);
+        $checker->checkClaim('baz');
+
+        $this->expectException(InvalidHeaderException::class);
+
+        $checker = new CallableChecker('foo', fn (mixed $value) => 0);
+        $checker->checkHeader('baz');
+    }
+
+    /**
+     * @test
+     */
+    public function theClaimIsInvalid(): void
+    {
+        $this->expectException(InvalidClaimException::class);
+
+        $checker = new CallableChecker('foo', fn (mixed $value) => $value === 'bar');
+        $checker->checkClaim('baz');
+    }
+
+    /**
+     * @test
+     */
+    public function theHeaderIsInvalid(): void
+    {
+        $this->expectException(InvalidHeaderException::class);
+
+        $checker = new CallableChecker('foo', fn (mixed $value) => $value === 'bar');
+        $checker->checkHeader('baz');
+    }
+
+    /**
+     * @test
+     */
+    public function theClaimIsSupported(): void
+    {
+        $checker = new CallableChecker('foo', fn (mixed $value) => $value === 'bar');
+        $checker->checkClaim('bar');
+
+        static::assertSame('foo', $checker->supportedClaim());
+    }
+
+    /**
+     * @test
+     */
+    public function theHeaderIsSupported(): void
+    {
+        $checker = new CallableChecker('foo', fn (mixed $value) => $value === 'bar');
+        $checker->checkHeader('bar');
+
+        static::assertSame('foo', $checker->supportedHeader());
+    }
+}
diff --git a/tests/Component/Checker/IsEqualCheckerTest.php b/tests/Component/Checker/IsEqualCheckerTest.php
new file mode 100644
index 00000000..2783f68f
--- /dev/null
+++ b/tests/Component/Checker/IsEqualCheckerTest.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Jose\Tests\Component\Checker;
+
+use Jose\Component\Checker\InvalidClaimException;
+use Jose\Component\Checker\InvalidHeaderException;
+use Jose\Component\Checker\IsEqualChecker;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @internal
+ */
+final class IsEqualCheckerTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function theClaimIsInvalid(): void
+    {
+        $this->expectException(InvalidClaimException::class);
+
+        $checker = new IsEqualChecker('foo', 'bar');
+        $checker->checkClaim('baz');
+    }
+
+    /**
+     * @test
+     */
+    public function theHeaderIsInvalid(): void
+    {
+        $this->expectException(InvalidHeaderException::class);
+
+        $checker = new IsEqualChecker('foo', 'bar');
+        $checker->checkHeader('baz');
+    }
+
+    /**
+     * @test
+     */
+    public function theClaimIsSupported(): void
+    {
+        $checker = new IsEqualChecker('foo', 'bar');
+        $checker->checkClaim('bar');
+        static::assertSame('foo', $checker->supportedClaim());
+    }
+
+    /**
+     * @test
+     */
+    public function theHeaderIsSupported(): void
+    {
+        $checker = new IsEqualChecker('foo', 'bar');
+        $checker->checkHeader('bar');
+        static::assertSame('foo', $checker->supportedHeader());
+    }
+}