diff --git a/lib/node_modules/@stdlib/array/uint64/README.md b/lib/node_modules/@stdlib/array/uint64/README.md
index 02da19409141..42bba3859e1c 100644
--- a/lib/node_modules/@stdlib/array/uint64/README.md
+++ b/lib/node_modules/@stdlib/array/uint64/README.md
@@ -335,6 +335,44 @@ var u = arr.get( 100 );
// returns undefined
```
+
+
+#### Uint64Array.prototype.reduce( reducerFn\[, initialValue] )
+
+Applies a provided callback function to each element of the array, in order, passing in the return value from the calculation on the preceding element and returning the accumulated result upon completion.
+
+```javascript
+var add = require( '@stdlib/number/uint64/base/add' );
+
+var arr = new Uint64Array( [ 1, 2, 3 ] );
+
+var u = arr.reduce( add );
+// returns [ 6n ]
+```
+
+The reducer function is provided four arguments:
+
+- **acc**: accumulated result.
+- **value**: current array element.
+- **index**: current array element index.
+- **arr**: the array on which this method was called.
+
+By default, the function initializes the accumulated result to the first element in the array and passes the second array element as `value` during the first invocation of the provided callback. To begin accumulation from a different starting value and pass in the first array element as `value` during the first invocation of the provided callback, provide an `initialValue` argument.
+
+```javascript
+var Number = require( '@stdlib/number/ctor' );
+
+function reducer( acc, v ) {
+ acc += Number( v );
+ return acc;
+}
+
+var arr = new Uint64Array( [ 1, 2, 3 ] );
+
+var sum = arr.reduce( reducer, 2 );
+// returns 8
+```
+
#### Uint64Array.prototype.set( value\[, i] )
diff --git a/lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.js b/lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.js
new file mode 100644
index 000000000000..b7376999c583
--- /dev/null
+++ b/lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.js
@@ -0,0 +1,81 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var bench = require( '@stdlib/bench' );
+var isUint64 = require( '@stdlib/assert/is-uint64' );
+var add = require( '@stdlib/number/uint64/base/add' );
+var Uint64 = require( '@stdlib/number/uint64/ctor' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var Uint64Array = require( './../lib' );
+
+
+// MAIN //
+
+bench( format( '%s:reduce', pkg ), function benchmark( b ) {
+ var out;
+ var arr;
+ var i;
+
+ arr = new Uint64Array( 10 );
+
+ // Benchmark worst case scenario (i.e., every element is visited and passed to the reducer)...
+ b.tic();
+ for ( i = 0; i < b.iterations; i++ ) {
+ out = arr.reduce( add );
+ if ( typeof out !== 'object' ) {
+ b.fail( 'should return an object' );
+ }
+ }
+ b.toc();
+ if ( !isUint64( out ) ) {
+ b.fail( 'should return a 64-bit unsigned integer' );
+ }
+ b.pass( 'benchmark finished' );
+ b.end();
+});
+
+bench( format( '%s::initial_value:reduce', pkg ), function benchmark( b ) {
+ var out;
+ var arr;
+ var v;
+ var i;
+
+ arr = new Uint64Array( 10 );
+
+ v = new Uint64( 0 );
+
+ // Benchmark worst case scenario (i.e., every element is visited and passed to the reducer)...
+ b.tic();
+ for ( i = 0; i < b.iterations; i++ ) {
+ out = arr.reduce( add, v );
+ if ( typeof out !== 'object' ) {
+ b.fail( 'should return an object' );
+ }
+ }
+ b.toc();
+ if ( !isUint64( out ) ) {
+ b.fail( 'should return a 64-bit unsigned integer' );
+ }
+ b.pass( 'benchmark finished' );
+ b.end();
+});
diff --git a/lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.length.js b/lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.length.js
new file mode 100644
index 000000000000..2336da53d722
--- /dev/null
+++ b/lib/node_modules/@stdlib/array/uint64/benchmark/benchmark.reduce.length.js
@@ -0,0 +1,97 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var bench = require( '@stdlib/bench' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var isUint64 = require( '@stdlib/assert/is-uint64' );
+var add = require( '@stdlib/number/uint64/base/add' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var Uint64Array = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+ var arr = new Uint64Array( len );
+ return benchmark;
+
+ /**
+ * Benchmark function.
+ *
+ * @private
+ * @param {Benchmark} b - benchmark instance
+ */
+ function benchmark( b ) {
+ var out;
+ var i;
+
+ // Benchmark worst case scenario (i.e., every element is visited and passed to the reducer)...
+ b.tic();
+ for ( i = 0; i < b.iterations; i++ ) {
+ out = arr.reduce( add );
+ if ( typeof out !== 'object' ) {
+ b.fail( 'should return an object' );
+ }
+ }
+ b.toc();
+ if ( !isUint64( out ) ) {
+ b.fail( 'should return a 64-bit unsigned integer' );
+ }
+ b.pass( 'benchmark finished' );
+ b.end();
+ }
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+*/
+function main() {
+ var len;
+ var min;
+ var max;
+ var f;
+ var i;
+
+ min = 1; // 10^min
+ max = 6; // 10^max
+
+ for ( i = min; i <= max; i++ ) {
+ len = pow( 10, i );
+ f = createBenchmark( len );
+ bench( format( '%s:reduce:len=%d', pkg, len ), f );
+ }
+}
+
+main();
diff --git a/lib/node_modules/@stdlib/array/uint64/docs/repl.txt b/lib/node_modules/@stdlib/array/uint64/docs/repl.txt
index c737fc5bf588..ecdc1ffaa839 100644
--- a/lib/node_modules/@stdlib/array/uint64/docs/repl.txt
+++ b/lib/node_modules/@stdlib/array/uint64/docs/repl.txt
@@ -299,6 +299,47 @@
[ 2n ]
+{{alias}}.prototype.reduce( reducerFn[, initialValue] )
+ Applies a provided function to each element of the array, in order, passing
+ in the return value from the calculation on the preceding element and
+ returning the accumulated result upon completion.
+
+ A reducer function is provided the following arguments:
+
+ - acc: accumulated result.
+ - value: current array element.
+ - index: current array element index.
+ - arr: the array on which the method was called.
+
+ If provided an initial value, the method invokes a provided function with
+ the initial value as the first argument and the first array element as the
+ second argument.
+
+ If not provided an initial value, the method invokes a provided function
+ with the first array element as the first argument and the second array
+ element as the second argument.
+
+ Parameters
+ ----------
+ reducerFn: Function
+ Function to apply to each array element.
+
+ initialValue: any (optional)
+ Initial accumulation value.
+
+ Returns
+ -------
+ out: any
+ Accumulated result.
+
+ Examples
+ --------
+ > var arr = new {{alias}}( [ 1, 2, 3 ] )
+ [ 1n, 2n, 3n ]
+ > var u = arr.reduce( {{alias:@stdlib/number/uint64/base/add}} )
+ [ 6n ]
+
+
{{alias}}.prototype.set( v[, i] )
Sets one or more array elements.
diff --git a/lib/node_modules/@stdlib/array/uint64/docs/types/index.d.ts b/lib/node_modules/@stdlib/array/uint64/docs/types/index.d.ts
index 78b11c503625..94bf3a3af0cb 100644
--- a/lib/node_modules/@stdlib/array/uint64/docs/types/index.d.ts
+++ b/lib/node_modules/@stdlib/array/uint64/docs/types/index.d.ts
@@ -477,6 +477,23 @@ declare class Uint64Array implements Uint64ArrayInterface {
*/
get( i: number ): Uint64 | void;
+ /**
+ * Applies a provided callback function to each element of the array, in order, passing in the return value from the calculation on the preceding element and returning the accumulated result upon completion.
+ *
+ * @param reducer - callback function
+ * @param initialValue - initial value
+ * @returns accumulated result
+ *
+ * @example
+ * var add = require( '@stdlib/number/uint64/base/add' );
+ *
+ * var arr = new Uint64Array( [ 1, 2, 3 ] );
+ *
+ * var u = arr.reduce( add );
+ * // returns [ 6n ]
+ */
+ reduce( reducer: Reducer, initialValue?: U ): U;
+
/**
* Sets an array element.
*
diff --git a/lib/node_modules/@stdlib/array/uint64/lib/main.js b/lib/node_modules/@stdlib/array/uint64/lib/main.js
index 684cb8e4b9bd..33f3bc9376f5 100644
--- a/lib/node_modules/@stdlib/array/uint64/lib/main.js
+++ b/lib/node_modules/@stdlib/array/uint64/lib/main.js
@@ -758,6 +758,58 @@ setReadOnlyAccessor( Uint64Array.prototype, 'length', function get() {
return this._length;
});
+/**
+* Applies a provided callback function to each element of the array, in order, passing in the return value from the calculation on the preceding element and returning the accumulated result upon completion.
+*
+* @name reduce
+* @memberof Uint64Array.prototype
+* @type {Function}
+* @param {Function} reducer - callback function
+* @param {*} [initialValue] - initial value
+* @throws {TypeError} `this` must be a 64-bit unsigned integer array
+* @throws {TypeError} first argument must be a function
+* @throws {Error} if not provided an initial value, the array must have at least one element
+* @returns {*} accumulated result
+*
+* @example
+* var add = require( '@stdlib/number/uint64/base/add' );
+*
+* var arr = new Uint64Array( [ 1, 2, 3 ] );
+*
+* var u = arr.reduce( add );
+* // returns [ 6n ]
+*/
+setReadOnly( Uint64Array.prototype, 'reduce', function reduce( reducer, initialValue ) {
+ var buf;
+ var acc;
+ var len;
+ var v;
+ var i;
+ if ( !isUint64Array( this ) ) {
+ throw new TypeError( 'invalid invocation. `this` is not a 64-bit unsigned integer array.' );
+ }
+ if ( !isFunction( reducer ) ) {
+ throw new TypeError( format( 'invalid argument. First argument must be a function. Value: `%s`.', reducer ) );
+ }
+ buf = this._buffer;
+ len = this._length;
+ if ( arguments.length > 1 ) {
+ acc = initialValue;
+ i = 0;
+ } else {
+ if ( len === 0 ) {
+ throw new Error( 'invalid operation. If not provided an initial value, an array must contain at least one element.' );
+ }
+ acc = getUint64( buf, 0 );
+ i = 1;
+ }
+ for ( ; i < len; i++ ) {
+ v = getUint64( buf, i );
+ acc = reducer( acc, v, i, this );
+ }
+ return acc;
+});
+
/**
* Sets an array element.
*
diff --git a/lib/node_modules/@stdlib/array/uint64/test/test.reduce.js b/lib/node_modules/@stdlib/array/uint64/test/test.reduce.js
new file mode 100644
index 000000000000..07d31060422a
--- /dev/null
+++ b/lib/node_modules/@stdlib/array/uint64/test/test.reduce.js
@@ -0,0 +1,204 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var tape = require( 'tape' );
+var hasOwnProp = require( '@stdlib/assert/has-own-property' );
+var isFunction = require( '@stdlib/assert/is-function' );
+var isUint64 = require( '@stdlib/assert/is-uint64' );
+var isEqual = require( '@stdlib/number/uint64/base/assert/is-equal' );
+var add = require( '@stdlib/number/uint64/base/add' );
+var Number = require( '@stdlib/number/ctor' );
+var Uint64 = require( '@stdlib/number/uint64/ctor' );
+var Uint64Array = require( './../lib' );
+
+
+// TESTS //
+
+tape( 'main export is a function', function test( t ) {
+ t.ok( true, __filename );
+ t.strictEqual( typeof Uint64Array, 'function', 'main export is a function' );
+ t.end();
+});
+
+tape( 'attached to the prototype of the main export is a `reduce` method', function test( t ) {
+ t.strictEqual( hasOwnProp( Uint64Array.prototype, 'reduce' ), true, 'has property' );
+ t.strictEqual( isFunction( Uint64Array.prototype.reduce ), true, 'has method' );
+ t.end();
+});
+
+tape( 'the method throws an error if invoked with a `this` context which is not a 64-bit unsigned integer array instance', function test( t ) {
+ var values;
+ var arr;
+ var i;
+
+ arr = new Uint64Array( 5 );
+
+ values = [
+ '5',
+ 5,
+ NaN,
+ true,
+ false,
+ null,
+ void 0,
+ {},
+ []
+ ];
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[i] ), TypeError, 'throws an error when provided '+values[i] );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ return arr.reduce.call( value, add );
+ };
+ }
+});
+
+tape( 'the method throws an error if provided a first argument which is not a function', function test( t ) {
+ var values;
+ var arr;
+ var i;
+
+ arr = new Uint64Array( 5 );
+
+ values = [
+ '5',
+ 5,
+ NaN,
+ true,
+ false,
+ null,
+ void 0,
+ {},
+ []
+ ];
+ for ( i = 0; i < values.length; i++ ) {
+ t.throws( badValue( values[i] ), TypeError, 'throws an error when provided '+values[i] );
+ }
+ t.end();
+
+ function badValue( value ) {
+ return function badValue() {
+ return arr.reduce( value );
+ };
+ }
+});
+
+tape( 'the method throws an error if not provided an initial value when operating on an empty 64-bit unsigned integer array', function test( t ) {
+ var arr;
+
+ arr = new Uint64Array( 0 );
+ t.throws( foo, Error, 'throws an error' );
+ t.end();
+
+ function foo() {
+ arr.reduce( add );
+ }
+});
+
+tape( 'the method uses the first element of the array as the initial value when an initial value is not provided', function test( t ) {
+ var valueArray;
+ var accArray;
+ var expected;
+ var actual;
+ var arr;
+
+ arr = new Uint64Array( [ 1, 2, 3 ] );
+ accArray = [ 1, 3 ];
+ valueArray = [ 2, 3 ];
+ expected = new Uint64( 6 );
+ actual = arr.reduce( reducer );
+
+ t.strictEqual( isUint64( actual ), true, 'returns expected value' );
+ t.strictEqual( isEqual( actual, expected ), true, 'returns expected value' );
+
+ t.end();
+
+ function reducer( acc, value, index ) {
+ var ind = index - 1;
+ t.strictEqual( isUint64( acc ), true, 'returns expected value' );
+ t.strictEqual( isEqual( acc, new Uint64( accArray[ ind ] ) ), true, 'returns expected value' );
+ t.strictEqual( isUint64( value ), true, 'returns expected value' );
+ t.strictEqual( isEqual( value, new Uint64( valueArray[ ind ] ) ), true, 'returns expected value' );
+ return add( acc, value );
+ }
+});
+
+tape( 'the method supports providing an initial value as the second argument', function test( t ) {
+ var valueArray;
+ var accArray;
+ var expected;
+ var actual;
+ var arr;
+
+ arr = new Uint64Array( [ 1, 2, 3 ] );
+ accArray = [ 2, 3, 5 ];
+ valueArray = [ 1, 2, 3 ];
+ expected = new Uint64( 8 );
+ actual = arr.reduce( reducer, new Uint64( 2 ) );
+
+ t.strictEqual( isUint64( actual ), true, 'returns expected value' );
+ t.strictEqual( isEqual( actual, expected ), true, 'returns expected value' );
+
+ t.end();
+
+ function reducer( acc, value, index ) {
+ t.strictEqual( isUint64( acc ), true, 'returns expected value' );
+ t.strictEqual( isEqual( acc, new Uint64( accArray[ index ] ) ), true, 'returns expected value' );
+ t.strictEqual( isUint64( value ), true, 'returns expected value' );
+ t.strictEqual( isEqual( value, new Uint64( valueArray[ index ] ) ), true, 'returns expected value' );
+ return add( acc, value );
+ }
+});
+
+tape( 'the method returns the accumulated result', function test( t ) {
+ var expected;
+ var actual;
+ var arr;
+
+ arr = new Uint64Array( [ 1, 2, 3 ] );
+ expected = new Uint64( 6 );
+ actual = arr.reduce( add );
+
+ t.strictEqual( isUint64( actual ), true, 'returns expected value' );
+ t.strictEqual( isEqual( actual, expected ), true, 'returns expected value' );
+ t.end();
+});
+
+tape( 'the method supports returning real-valued results', function test( t ) {
+ var expected;
+ var actual;
+ var arr;
+
+ arr = new Uint64Array( [ 1, 2, 3 ] );
+ expected = 6;
+ actual = arr.reduce( reducer, 0 );
+
+ t.strictEqual( actual, expected, 'returns expected value' );
+ t.end();
+
+ function reducer( acc, value ) {
+ return acc + Number( value );
+ }
+});