diff --git a/tfjs-backend-cpu/package.json b/tfjs-backend-cpu/package.json
index 8fed43cf62d..86efac109d8 100644
--- a/tfjs-backend-cpu/package.json
+++ b/tfjs-backend-cpu/package.json
@@ -70,5 +70,10 @@
   "browser": {
     "util": false,
     "crypto": false
-  }
+  },
+  "sideEffects": [
+    "./dist/register_all_kernels.js",
+    "./dist/base.js",
+    "./dist/index.js"
+  ]
 }
diff --git a/tfjs-backend-cpu/src/base.ts b/tfjs-backend-cpu/src/base.ts
index 17fa0f9f063..60d137700c1 100644
--- a/tfjs-backend-cpu/src/base.ts
+++ b/tfjs-backend-cpu/src/base.ts
@@ -17,10 +17,15 @@
 
 /*
  * base.ts contains all the exports from tfjs-backend-cpu
- * that do not trigger side effects.
+ * without auto-kernel registration
  */
+import {registerBackend} from '@tensorflow/tfjs-core';
+import {MathBackendCPU} from './backend_cpu';
 import * as shared from './shared';
 
 export {MathBackendCPU} from './backend_cpu';
 export {version as version_cpu} from './version';
 export {shared};
+
+// Side effects for default initialization of MathBackendCPU
+registerBackend('cpu', () => new MathBackendCPU(), 1 /* priority */);
diff --git a/tfjs-backend-cpu/src/index.ts b/tfjs-backend-cpu/src/index.ts
index 53ca24399c5..abf89246ec3 100644
--- a/tfjs-backend-cpu/src/index.ts
+++ b/tfjs-backend-cpu/src/index.ts
@@ -15,12 +15,6 @@
  * =============================================================================
  */
 
-import {registerBackend} from '@tensorflow/tfjs-core';
-import {MathBackendCPU} from './base';
-
-// Side effects for default initialization of MathBackendCPU
-registerBackend('cpu', () => new MathBackendCPU(), 1 /* priority */);
-import './register_all_kernels';
-
 // All exports from this package should be in base.
 export * from './base';
+import './register_all_kernels';
diff --git a/tfjs-backend-webgl/package.json b/tfjs-backend-webgl/package.json
index 64b91654b52..f2de6562434 100644
--- a/tfjs-backend-webgl/package.json
+++ b/tfjs-backend-webgl/package.json
@@ -80,5 +80,11 @@
   "browser": {
     "util": false,
     "crypto": false
-  }
+  },
+  "sideEffects": [
+    "./dist/register_all_kernels.js",
+    "./dist/flags_webgl.js",
+    "./dist/base.js",
+    "./dist/index.js"
+  ]
 }
diff --git a/tfjs-backend-webgl/src/base.ts b/tfjs-backend-webgl/src/base.ts
new file mode 100644
index 00000000000..f2412eab16a
--- /dev/null
+++ b/tfjs-backend-webgl/src/base.ts
@@ -0,0 +1,33 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+// base.ts is the webgl backend without auto kernel registration.
+
+import {device_util, registerBackend} from '@tensorflow/tfjs-core';
+import {MathBackendWebGL} from './backend_webgl';
+export {version as version_webgl} from './version';
+
+if (device_util.isBrowser()) {
+  registerBackend('webgl', () => new MathBackendWebGL(), 2 /* priority */);
+}
+
+// Export webgl utilities
+export * from './webgl';
+
+// Export forceHalfFlost under webgl namespace for the union bundle.
+import {forceHalfFloat} from './webgl';
+export const webgl = {forceHalfFloat};
diff --git a/tfjs-backend-webgl/src/index.ts b/tfjs-backend-webgl/src/index.ts
index 14f5863c480..abf89246ec3 100644
--- a/tfjs-backend-webgl/src/index.ts
+++ b/tfjs-backend-webgl/src/index.ts
@@ -15,18 +15,6 @@
  * =============================================================================
  */
 
-import {device_util, registerBackend} from '@tensorflow/tfjs-core';
-import {MathBackendWebGL} from './backend_webgl';
-export {version as version_webgl} from './version';
-
-if (device_util.isBrowser()) {
-  registerBackend('webgl', () => new MathBackendWebGL(), 2 /* priority */);
-}
+// All exports from this package should be in base.
+export * from './base';
 import './register_all_kernels';
-
-// Export webgl utilities
-export * from './webgl';
-
-// Export forceHalfFlost under webgl namespace for the union bundle.
-import {forceHalfFloat} from './webgl';
-export const webgl = {forceHalfFloat};
diff --git a/tfjs-backend-webgl/src/kernel_utils/shared.ts b/tfjs-backend-webgl/src/kernel_utils/shared.ts
index c5b51211eef..0ac71e981c0 100644
--- a/tfjs-backend-webgl/src/kernel_utils/shared.ts
+++ b/tfjs-backend-webgl/src/kernel_utils/shared.ts
@@ -18,7 +18,7 @@
 // Import shared functionality from tfjs-backend-cpu without triggering
 // side effects.
 // tslint:disable-next-line: no-imports-from-dist
-import {shared} from '@tensorflow/tfjs-backend-cpu/dist/base';
+import * as shared from '@tensorflow/tfjs-backend-cpu/dist/shared';
 
 const {maxImpl: maxImplCPU, transposeImpl: transposeImplCPU} = shared;
 
diff --git a/tfjs-core/package.json b/tfjs-core/package.json
index 1d73f344c78..74ef2a84f50 100644
--- a/tfjs-core/package.json
+++ b/tfjs-core/package.json
@@ -91,5 +91,15 @@
     "node-fetch": false,
     "util": false,
     "crypto": false
-  }
+  },
+  "sideEffects": [
+    "./dist/index.js",
+    "./dist/base_side_effects.js",
+    "./dist/engine.js",
+    "./dist/flags.js",
+    "./dist/platforms/*.js",
+    "./dist/register_all_gradients.js",
+    "./dist/public/chained_ops/*.js",
+    "./dist/io/*.js"
+  ]
 }
diff --git a/tfjs-core/src/base.ts b/tfjs-core/src/base.ts
new file mode 100644
index 00000000000..831f00dee0a
--- /dev/null
+++ b/tfjs-core/src/base.ts
@@ -0,0 +1,101 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+// base.ts is tfjs-core without auto registration of gradients or chained ops.
+
+/**
+ * @fileoverview
+ * @suppress {partialAlias} Optimization disabled due to passing the module
+ * object into a function below:
+ *
+ *   import * as ops from './ops/ops';
+ *   setOpHandler(ops);
+ */
+
+// Serialization.
+import * as io from './io/io';
+import * as math from './math';
+import * as browser from './ops/browser';
+import * as gather_util from './ops/gather_nd_util';
+import * as scatter_util from './ops/scatter_nd_util';
+import * as slice_util from './ops/slice_util';
+import * as serialization from './serialization';
+import {setOpHandler} from './tensor';
+import * as tensor_util from './tensor_util';
+import * as test_util from './test_util';
+import * as util from './util';
+import {version} from './version';
+
+export {InferenceModel, MetaGraph, MetaGraphInfo, ModelPredictConfig, ModelTensorInfo, SavedModelTensorInfo, SignatureDef, SignatureDefInfo} from './model_types';
+// Optimizers.
+export {AdadeltaOptimizer} from './optimizers/adadelta_optimizer';
+export {AdagradOptimizer} from './optimizers/adagrad_optimizer';
+export {AdamOptimizer} from './optimizers/adam_optimizer';
+export {AdamaxOptimizer} from './optimizers/adamax_optimizer';
+export {MomentumOptimizer} from './optimizers/momentum_optimizer';
+export {Optimizer} from './optimizers/optimizer';
+export {RMSPropOptimizer} from './optimizers/rmsprop_optimizer';
+export {SGDOptimizer} from './optimizers/sgd_optimizer';
+export {Scalar, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D, TensorBuffer, Variable} from './tensor';
+export {GradSaveFunc, NamedTensorMap, TensorContainer, TensorContainerArray, TensorContainerObject} from './tensor_types';
+export {BackendValues, DataType, DataTypeMap, DataValues, NumericDataType, PixelData, Rank, RecursiveArray, ScalarLike, ShapeMap, sumOutType, TensorLike, TypedArray, upcastType} from './types';
+
+export * from './ops/ops';
+export {Reduction} from './ops/loss_ops_utils';
+
+export * from './train';
+export * from './globals';
+export * from './kernel_registry';
+export {customGrad, grad, grads, valueAndGrad, valueAndGrads, variableGrads} from './gradients';
+
+export {TimingInfo, MemoryInfo, ForwardFunc} from './engine';
+export {Environment, env, ENV} from './environment';
+export {Platform} from './platforms/platform';
+
+export {version as version_core};
+
+// Top-level method exports.
+export {nextFrame} from './browser_util';
+
+// Second level exports.
+import * as backend_util from './backends/backend_util';
+import * as device_util from './device_util';
+export {
+  browser,
+  io,
+  math,
+  serialization,
+  test_util,
+  util,
+  backend_util,
+  tensor_util,
+  slice_util,
+  gather_util,
+  scatter_util,
+  device_util
+};
+
+import * as kernel_impls from './backends/kernel_impls';
+export {kernel_impls};
+// Backend specific.
+export {KernelBackend, BackendTimingInfo, DataMover, DataStorage} from './backends/backend';
+
+import * as ops from './ops/ops';
+setOpHandler(ops);
+
+// Export all kernel names / info.
+export * from './kernel_names';
diff --git a/tfjs-core/src/base_side_effects.ts b/tfjs-core/src/base_side_effects.ts
new file mode 100644
index 00000000000..f645809a7c1
--- /dev/null
+++ b/tfjs-core/src/base_side_effects.ts
@@ -0,0 +1,27 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+// Required side effectful code for tfjs-core (in any build)
+
+// Engine is the global singleton that needs to be initialized before the rest
+// of the app.
+import './engine';
+// Register backend-agnostic flags.
+import './flags';
+// Register platforms
+import './platforms/platform_browser';
+import './platforms/platform_node';
diff --git a/tfjs-core/src/index.ts b/tfjs-core/src/index.ts
index 49a95123436..52090c4e992 100644
--- a/tfjs-core/src/index.ts
+++ b/tfjs-core/src/index.ts
@@ -15,98 +15,12 @@
  * =============================================================================
  */
 
-/**
- * @fileoverview
- * @suppress {partialAlias} Optimization disabled due to passing the module
- * object into a function below:
- *
- *   import * as ops from './ops/ops';
- *   setOpHandler(ops);
- */
+// Required side effectful code.
+import './base_side_effects';
+// All exports from this package should be in base.
+export * from './base';
 
-// Engine is the global singleton that needs to be initialized before the rest
-// of the app.
-import './engine';
-// Register backend-agnostic flags.
-import './flags';
 // Register all the gradients.
 import './register_all_gradients';
-import './platforms/platform_browser';
-import './platforms/platform_node';
-
-// Serialization.
-import * as io from './io/io';
-import * as math from './math';
-import * as browser from './ops/browser';
-import * as gather_util from './ops/gather_nd_util';
-import * as scatter_util from './ops/scatter_nd_util';
-import * as slice_util from './ops/slice_util';
-import * as serialization from './serialization';
-import {setOpHandler} from './tensor';
-import * as tensor_util from './tensor_util';
-import * as test_util from './test_util';
-import * as util from './util';
-import {version} from './version';
-
-export {InferenceModel, MetaGraph, MetaGraphInfo, ModelPredictConfig, ModelTensorInfo, SavedModelTensorInfo, SignatureDef, SignatureDefInfo} from './model_types';
-// Optimizers.
-export {AdadeltaOptimizer} from './optimizers/adadelta_optimizer';
-export {AdagradOptimizer} from './optimizers/adagrad_optimizer';
-export {AdamOptimizer} from './optimizers/adam_optimizer';
-export {AdamaxOptimizer} from './optimizers/adamax_optimizer';
-export {MomentumOptimizer} from './optimizers/momentum_optimizer';
-export {Optimizer} from './optimizers/optimizer';
-export {RMSPropOptimizer} from './optimizers/rmsprop_optimizer';
-export {SGDOptimizer} from './optimizers/sgd_optimizer';
-export {Scalar, Tensor, Tensor1D, Tensor2D, Tensor3D, Tensor4D, Tensor5D, TensorBuffer, Variable} from './tensor';
-export {GradSaveFunc, NamedTensorMap, TensorContainer, TensorContainerArray, TensorContainerObject} from './tensor_types';
-export {BackendValues, DataType, DataTypeMap, DataValues, NumericDataType, PixelData, Rank, RecursiveArray, ScalarLike, ShapeMap, sumOutType, TensorLike, TypedArray, upcastType} from './types';
-
-export * from './ops/ops';
-export {Reduction} from './ops/loss_ops_utils';
-
-export * from './train';
-export * from './globals';
-export * from './kernel_registry';
-export {customGrad, grad, grads, valueAndGrad, valueAndGrads, variableGrads} from './gradients';
-
-export {TimingInfo, MemoryInfo, ForwardFunc} from './engine';
-export {Environment, env, ENV} from './environment';
-export {Platform} from './platforms/platform';
-
-export {version as version_core};
-
-// Top-level method exports.
-export {nextFrame} from './browser_util';
-
-// Second level exports.
-import * as backend_util from './backends/backend_util';
-import * as device_util from './device_util';
-export {
-  browser,
-  io,
-  math,
-  serialization,
-  test_util,
-  util,
-  backend_util,
-  tensor_util,
-  slice_util,
-  gather_util,
-  scatter_util,
-  device_util
-};
-
-import * as kernel_impls from './backends/kernel_impls';
-export {kernel_impls};
-// Backend specific.
-export {KernelBackend, BackendTimingInfo, DataMover, DataStorage} from './backends/backend';
-
-import * as ops from './ops/ops';
-setOpHandler(ops);
-
-// Export all kernel names / info.
-export * from './kernel_names';
-
 // Import all op chainers and add type info to Tensor.
 import './public/chained_ops/register_all_chained_ops';
diff --git a/tfjs-core/src/ops/browser.ts b/tfjs-core/src/ops/browser.ts
index 22aba683829..e060db10fa1 100644
--- a/tfjs-core/src/ops/browser.ts
+++ b/tfjs-core/src/ops/browser.ts
@@ -23,6 +23,9 @@ import {NamedTensorMap} from '../tensor_types';
 import {convertToTensor} from '../tensor_util_env';
 import {PixelData, TensorLike} from '../types';
 
+import {cast} from './cast';
+import {max} from './max';
+import {min} from './min';
 import {op} from './operation';
 import {tensor3d} from './tensor3d';
 
@@ -177,7 +180,7 @@ export async function toPixels(
   if (!(img instanceof Tensor)) {
     // Assume int32 if user passed a native array.
     const originalImgTensor = $img;
-    $img = originalImgTensor.toInt();
+    $img = cast(originalImgTensor, 'int32');
     originalImgTensor.dispose();
   }
   if ($img.rank !== 2 && $img.rank !== 3) {
@@ -194,26 +197,26 @@ export async function toPixels(
   }
 
   const data = await $img.data();
-  const minTensor = $img.min();
-  const maxTensor = $img.max();
+  const minTensor = min($img);
+  const maxTensor = max($img);
   const vals = await Promise.all([minTensor.data(), maxTensor.data()]);
   const minVals = vals[0];
   const maxVals = vals[1];
-  const min = minVals[0];
-  const max = maxVals[0];
+  const minVal = minVals[0];
+  const maxVal = maxVals[0];
   minTensor.dispose();
   maxTensor.dispose();
   if ($img.dtype === 'float32') {
-    if (min < 0 || max > 1) {
+    if (minVal < 0 || maxVal > 1) {
       throw new Error(
           `Tensor values for a float32 Tensor must be in the ` +
-          `range [0 - 1] but got range [${min} - ${max}].`);
+          `range [0 - 1] but got range [${minVal} - ${maxVal}].`);
     }
   } else if ($img.dtype === 'int32') {
-    if (min < 0 || max > 255) {
+    if (minVal < 0 || maxVal > 255) {
       throw new Error(
           `Tensor values for a int32 Tensor must be in the ` +
-          `range [0 - 255] but got range [${min} - ${max}].`);
+          `range [0 - 255] but got range [${minVal} - ${maxVal}].`);
     }
   } else {
     throw new Error(
diff --git a/tfjs/package.json b/tfjs/package.json
index 97c0c28745b..63683a0df16 100644
--- a/tfjs/package.json
+++ b/tfjs/package.json
@@ -14,6 +14,9 @@
     "url": "https://github.com/tensorflow/tfjs.git"
   },
   "license": "Apache-2.0",
+  "bin": {
+    "tfjs-custom-bundle": "dist/tools/custom_bundle/cli.js"
+  },
   "devDependencies": {
     "@babel/core": "^7.9.0",
     "@babel/preset-env": "^7.9.5",
@@ -67,12 +70,15 @@
     "build-backend-webgl-ci": "cd ../tfjs-backend-webgl && yarn && yarn build-ci",
     "build-deps": "yarn build-core && yarn build-layers && yarn build-converter && yarn build-data && yarn build-backend-cpu && yarn build-backend-webgl",
     "build-deps-ci": "yarn build-core-ci && yarn build-layers-ci && yarn build-converter-ci && yarn build-data-ci && yarn build-backend-cpu-ci && yarn build-backend-webgl-ci",
+    "build-cli": "tsc --project ./tools/custom_bundle/tsconfig.json && chmod +x ./dist/tools/custom_bundle/cli.js",
+    "run-custom-build": "ts-node -s ./src/tools/custom_bundle/cli.ts",
     "build-npm": "./scripts/build-npm.sh",
     "link-local": "yalc link",
     "publish-local": "yarn build-npm && yalc push",
     "publish-npm": "npm publish",
     "lint": "tslint -p . -t verbose",
     "test": "yarn && yarn build-deps && yarn build && karma start",
+    "test-tools": "ts-node --project ./tools/custom_bundle/tsconfig.json run_tools_tests.ts",
     "test-ci": "./scripts/test-ci.sh"
   },
   "dependencies": {
@@ -82,6 +88,8 @@
     "@tensorflow/tfjs-core": "link:../tfjs-core",
     "@tensorflow/tfjs-data": "link:../tfjs-data",
     "@tensorflow/tfjs-layers": "link:../tfjs-layers",
+    "argparse": "^1.0.10",
+    "chalk": "^4.1.0",
     "core-js": "3",
     "regenerator-runtime": "^0.13.5"
   }
diff --git a/tfjs/run_tools_tests.ts b/tfjs/run_tools_tests.ts
new file mode 100644
index 00000000000..cd7e46bc933
--- /dev/null
+++ b/tfjs/run_tools_tests.ts
@@ -0,0 +1,32 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+// tslint:disable-next-line:no-require-imports
+const jasmineCtor = require('jasmine');
+// tslint:disable-next-line:no-require-imports
+
+Error.stackTraceLimit = Infinity;
+
+process.on('unhandledRejection', e => {
+  throw e;
+});
+const toolsTests = './tools/**/*_test.ts';
+
+const runner = new jasmineCtor();
+runner.loadConfig({spec_files: [toolsTests], random: false});
+
+runner.execute();
diff --git a/tfjs/scripts/test-ci.sh b/tfjs/scripts/test-ci.sh
index 85f5fd0cb50..8316f8414d6 100755
--- a/tfjs/scripts/test-ci.sh
+++ b/tfjs/scripts/test-ci.sh
@@ -18,6 +18,7 @@
 set -e
 
 yarn karma start --browsers='bs_firefox_mac,bs_chrome_mac' --singleRun
+yarn test-tools
 # cd integration_tests
 # yarn benchmark-cloud
 # Reinstall the following line once https://github.com/tensorflow/tfjs/pull/1663
diff --git a/tfjs/tools/custom_bundle/cli.ts b/tfjs/tools/custom_bundle/cli.ts
new file mode 100755
index 00000000000..d94fc76ca14
--- /dev/null
+++ b/tfjs/tools/custom_bundle/cli.ts
@@ -0,0 +1,113 @@
+#!/usr/bin/env node
+
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+/**
+ * Entry point for cli tool to build custom tfjs bundles
+ */
+
+import * as argparse from 'argparse';
+import * as chalk from 'chalk';
+import * as fs from 'fs';
+
+import {getCustomModuleString} from './custom_module';
+import {CustomTFJSBundleConfig, SupportedBackends} from './types';
+import {esmModuleProvider} from './esm_module_provider';
+
+const DEFAULT_CUSTOM_BUNDLE_ARGS: Partial<CustomTFJSBundleConfig> = {
+  entries: [],
+  models: [],
+  kernels: [],
+  forwardModeOnly: true,
+  backends: ['cpu', 'webgl'],
+};
+
+const parser = new argparse.ArgumentParser();
+parser.addArgument(
+    '--config', {help: 'path to custom bundle config file.', required: true});
+
+function bail(errorMsg: string) {
+  console.log(chalk.red(errorMsg));
+  process.exit(1);
+}
+
+function validateArgs(): CustomTFJSBundleConfig {
+  const args = parser.parseArgs();
+  const configFilePath = args.config;
+  if (!fs.existsSync(configFilePath)) {
+    bail(`Error: config file does not exist at ${configFilePath}`);
+  }
+  let config;
+  try {
+    config = JSON.parse(fs.readFileSync(configFilePath, 'utf-8'));
+  } catch (error) {
+    bail(`Error could not read/parse JSON config file. \n ${error.message}`);
+  }
+
+  if (config.outputPath == null) {
+    bail('Error: config must specify "outputPath" property');
+  }
+
+  console.log(`Using custom bundle configuration from ${
+      configFilePath}. Final config:`);
+  const replacer: null = null;
+  const space = 2;
+  console.log(`${JSON.stringify(config, replacer, space)}\n`);
+
+  const finalConfig = Object.assign({}, DEFAULT_CUSTOM_BUNDLE_ARGS, config);
+
+  if (finalConfig.entries.length !== 0) {
+    bail('Error: config.entries not yet supported');
+  }
+
+  if (finalConfig.models.length !== 0) {
+    bail('Error: config.models not yet supported');
+  }
+
+  for (const requestedBackend of finalConfig.backends) {
+    if (requestedBackend !== SupportedBackends.cpu &&
+        requestedBackend !== SupportedBackends.webgl) {
+      bail(`Error: Unsupported backend specified '${requestedBackend}'`);
+    }
+  }
+
+  return finalConfig;
+}
+
+function getKernelNamesForConfig(config: CustomTFJSBundleConfig) {
+  // Later on this will do a union of kernels from entries, models and kernels,
+  // (and kernels used by the converter itself) Currently we only support
+  // directly listing kernels. remember that this also needs to handle
+  // kernels used by gradients if forwardModeOnly is false.
+  return config.kernels;
+}
+function produceCustomTFJSModule(
+    kernels: string[], backends: string[], forwardModeOnly: boolean,
+    outputPath: string) {
+  const moduleStr = getCustomModuleString(
+      kernels, backends, forwardModeOnly, esmModuleProvider);
+
+  console.log(`Writing custom tfjs module to ${outputPath}`);
+  fs.writeFileSync(outputPath, moduleStr);
+}
+
+const customConfig = validateArgs();
+const kernelsToInclude = getKernelNamesForConfig(customConfig);
+produceCustomTFJSModule(
+    kernelsToInclude, customConfig.backends, customConfig.forwardModeOnly,
+    customConfig.outputPath);
diff --git a/tfjs/tools/custom_bundle/custom_module.ts b/tfjs/tools/custom_bundle/custom_module.ts
new file mode 100644
index 00000000000..9725e9f6483
--- /dev/null
+++ b/tfjs/tools/custom_bundle/custom_module.ts
@@ -0,0 +1,63 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+import {ModuleProvider} from './types';
+
+export function getCustomModuleString(
+    kernels: string[],
+    backends: string[],
+    forwardModeOnly: boolean,
+    moduleProvider: ModuleProvider,
+    ): string {
+  const result: string[] = [];
+
+  addLine(result, moduleProvider.importCoreStr());
+  addLine(result, moduleProvider.importConverterStr());
+
+  for (const backend of backends) {
+    addLine(result, `\n//backend = ${backend}`);
+    addLine(result, moduleProvider.importBackendStr(backend));
+    for (const kernelName of kernels) {
+      const kernelImport = moduleProvider.importKernelStr(kernelName, backend);
+      addLine(result, kernelImport.importStatement);
+      addLine(result, registerKernelStr(kernelImport.kernelConfigId));
+    }
+  }
+
+  if (!forwardModeOnly) {
+    addLine(result, `\n//Gradients`);
+    for (const kernelName of kernels) {
+      const gradImport = moduleProvider.importGradientConfigStr(kernelName);
+      addLine(result, gradImport.importStatement);
+      addLine(result, registerGradientConfigStr(gradImport.gradConfigId));
+    }
+  }
+
+  return result.join('\n');
+}
+
+function addLine(target: string[], line: string) {
+  target.push(line);
+}
+
+function registerKernelStr(kernelConfigId: string) {
+  return `registerKernel(${kernelConfigId});`;
+}
+
+function registerGradientConfigStr(gradConfigId: string) {
+  return `registerGradient(${gradConfigId});`;
+}
diff --git a/tfjs/tools/custom_bundle/custom_module_test.ts b/tfjs/tools/custom_bundle/custom_module_test.ts
new file mode 100644
index 00000000000..ce7549fc738
--- /dev/null
+++ b/tfjs/tools/custom_bundle/custom_module_test.ts
@@ -0,0 +1,165 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+import {getCustomModuleString} from './custom_module';
+import {ModuleProvider} from './types';
+
+const mockModuleProvider: ModuleProvider = {
+  importCoreStr: () => 'import CORE',
+  importConverterStr: () => 'import CONVERTER',
+  importBackendStr: (name: string) => `import BACKEND ${name}`,
+  importKernelStr: (kernelName: string, backend: string) => ({
+    importStatement: `import KERNEL ${kernelName} from BACKEND ${backend}`,
+    kernelConfigId: `${kernelName}_${backend}`
+  }),
+  importGradientConfigStr: (kernel: string) => ({
+    importStatement: `import GRADIENT ${kernel}`,
+    gradConfigId: `${kernel}_GRAD_CONFIG`,
+  }),
+};
+
+describe('ESM Module Provider forwardModeOnly=true', () => {
+  const forwardModeOnly = true;
+  it('one kernel, one backend', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl'], ['FastBcknd'], forwardModeOnly, mockModuleProvider);
+
+    expect(res).toContain('import CORE');
+    expect(res).toContain('import CONVERTER');
+
+    expect(res).toContain('import BACKEND FastBcknd');
+    expect(res).toContain('import KERNEL MathKrnl from BACKEND FastBcknd');
+    expect(res).toContain('registerKernel(MathKrnl_FastBcknd)');
+
+    expect(res).not.toContain('GRADIENT');
+  });
+
+  it('one kernel, two backend', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl'], ['FastBcknd', 'SlowBcknd'], forwardModeOnly,
+        mockModuleProvider);
+
+    expect(res).toContain('import CORE');
+    expect(res).toContain('import CONVERTER');
+
+    expect(res).toContain('import BACKEND FastBcknd');
+    expect(res).toContain('import KERNEL MathKrnl from BACKEND FastBcknd');
+    expect(res).toContain('registerKernel(MathKrnl_FastBcknd)');
+
+    expect(res).toContain('import BACKEND SlowBcknd');
+    expect(res).toContain('import KERNEL MathKrnl from BACKEND SlowBcknd');
+    expect(res).toContain('registerKernel(MathKrnl_SlowBcknd)');
+
+    expect(res).not.toContain('GRADIENT');
+  });
+
+  it('two kernels, one backend', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl', 'MathKrn2'], ['FastBcknd'], forwardModeOnly,
+        mockModuleProvider);
+
+    expect(res).toContain('import CORE');
+    expect(res).toContain('import CONVERTER');
+
+    expect(res).toContain('import BACKEND FastBcknd');
+    expect(res).toContain('import KERNEL MathKrnl from BACKEND FastBcknd');
+    expect(res).toContain('import KERNEL MathKrn2 from BACKEND FastBcknd');
+    expect(res).toContain('registerKernel(MathKrnl_FastBcknd)');
+    expect(res).toContain('registerKernel(MathKrn2_FastBcknd)');
+
+    expect(res).not.toContain('GRADIENT');
+  });
+
+  it('two kernels, two backends', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl', 'MathKrn2'], ['FastBcknd', 'SlowBcknd'], forwardModeOnly,
+        mockModuleProvider);
+
+    expect(res).toContain('import CORE');
+    expect(res).toContain('import CONVERTER');
+
+    expect(res).toContain('import BACKEND FastBcknd');
+    expect(res).toContain('import KERNEL MathKrnl from BACKEND FastBcknd');
+    expect(res).toContain('import KERNEL MathKrn2 from BACKEND FastBcknd');
+    expect(res).toContain('registerKernel(MathKrnl_FastBcknd)');
+    expect(res).toContain('registerKernel(MathKrn2_FastBcknd)');
+
+    expect(res).toContain('import BACKEND SlowBcknd');
+    expect(res).toContain('import KERNEL MathKrnl from BACKEND SlowBcknd');
+    expect(res).toContain('import KERNEL MathKrn2 from BACKEND SlowBcknd');
+    expect(res).toContain('registerKernel(MathKrnl_SlowBcknd)');
+    expect(res).toContain('registerKernel(MathKrn2_SlowBcknd)');
+
+    expect(res).not.toContain('GRADIENT');
+  });
+});
+
+describe('ESM Module Provider forwardModeOnly=false', () => {
+  const forwardModeOnly = false;
+
+  it('one kernel, one backend', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl'], ['FastBcknd'], forwardModeOnly, mockModuleProvider);
+
+    expect(res).toContain('import CORE');
+    expect(res).toContain('import CONVERTER');
+
+    expect(res).toContain('import BACKEND FastBcknd');
+    expect(res).toContain('import KERNEL MathKrnl from BACKEND FastBcknd');
+    expect(res).toContain('registerKernel(MathKrnl_FastBcknd)');
+
+    expect(res).toContain('import GRADIENT MathKrnl');
+    expect(res).toContain('registerGradient(MathKrnl_GRAD_CONFIG)');
+  });
+
+  it('one kernel, two backend', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl'], ['FastBcknd', 'SlowBcknd'], forwardModeOnly,
+        mockModuleProvider);
+
+    expect(res).toContain('import GRADIENT MathKrnl');
+    expect(res).toContain('registerGradient(MathKrnl_GRAD_CONFIG)');
+
+    const gradIndex = res.indexOf('GRADIENT');
+    expect(res.indexOf('GRADIENT', gradIndex + 1))
+        .toBe(-1, `Gradient import appears twice in:\n ${res}`);
+  });
+
+  it('two kernels, one backend', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl', 'MathKrn2'], ['FastBcknd'], forwardModeOnly,
+        mockModuleProvider);
+
+    expect(res).toContain('import GRADIENT MathKrnl');
+    expect(res).toContain('registerGradient(MathKrnl_GRAD_CONFIG)');
+
+    expect(res).toContain('import GRADIENT MathKrn2');
+    expect(res).toContain('registerGradient(MathKrn2_GRAD_CONFIG)');
+  });
+
+  it('two kernels, two backends', () => {
+    const res = getCustomModuleString(
+        ['MathKrnl', 'MathKrn2'], ['FastBcknd', 'SlowBcknd'], forwardModeOnly,
+        mockModuleProvider);
+
+    expect(res).toContain('import GRADIENT MathKrnl');
+    expect(res).toContain('registerGradient(MathKrnl_GRAD_CONFIG)');
+
+    expect(res).toContain('import GRADIENT MathKrn2');
+    expect(res).toContain('registerGradient(MathKrn2_GRAD_CONFIG)');
+  });
+});
diff --git a/tfjs/tools/custom_bundle/esm_module_provider.ts b/tfjs/tools/custom_bundle/esm_module_provider.ts
new file mode 100644
index 00000000000..24d31cdfc5d
--- /dev/null
+++ b/tfjs/tools/custom_bundle/esm_module_provider.ts
@@ -0,0 +1,81 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+import {ModuleProvider, SupportedBackend} from './types';
+
+/**
+ * A module provider to generate custom esm modules.
+ */
+export const esmModuleProvider: ModuleProvider = {
+  importCoreStr() {
+    return `
+import {registerKernel, registerGradient} from '@tensorflow/tfjs-core/dist/base';
+import '@tensorflow/tfjs-core/dist/base_side_effects';
+export * from '@tensorflow/tfjs-core/dist/base';
+  `;
+  },
+
+  importConverterStr() {
+    return `export * from '@tensorflow/tfjs-converter';`;
+  },
+
+  importBackendStr(backend: SupportedBackend) {
+    const backendPkg = getBackendPath(backend);
+    return `export * from '${backendPkg}/dist/base';`;
+  },
+
+  importKernelStr(kernelName: string, backend: SupportedBackend) {
+    // TODO(yassogba) validate whether the target file referenced by
+    // importStatement exists and warn the user if it doesn't. That could happen
+    // here or in an earlier validation phase that uses this function
+
+    const backendPkg = getBackendPath(backend);
+    const kernelConfigId = `${kernelName}_${backend}`;
+    const importStatement =
+        `import {${kernelNameToVariableName(kernelName)}Config as ${
+            kernelConfigId}} from '${backendPkg}/dist/kernels/${kernelName}';`;
+
+    return {importStatement, kernelConfigId};
+  },
+
+  importGradientConfigStr(kernelName: string) {
+    // TODO(yassogba) validate whether the target file referenced by
+    // importStatement exists and warn the user if it doesn't. That could happen
+    // here or in an earlier validation phase that uses this function
+
+    const gradConfigId = `${kernelNameToVariableName(kernelName)}GradConfig`;
+    const importStatement =
+        `import {${gradConfigId}} from '@tensorflow/tfjs-core/dist/gradients/${
+            kernelName}_grad';`;
+
+    return {importStatement, gradConfigId};
+  }
+};
+
+function getBackendPath(backend: SupportedBackend) {
+  switch (backend) {
+    case 'cpu':
+      return '@tensorflow/tfjs-backend-cpu';
+    case 'webgl':
+      return '@tensorflow/tfjs-backend-webgl';
+    default:
+      throw new Error(`Unsupported backend ${backend}`);
+  }
+}
+
+function kernelNameToVariableName(kernelName: string) {
+  return kernelName.charAt(0).toLowerCase() + kernelName.slice(1);
+}
diff --git a/tfjs/tools/custom_bundle/esm_module_provider_test.ts b/tfjs/tools/custom_bundle/esm_module_provider_test.ts
new file mode 100644
index 00000000000..aac2acf5c6b
--- /dev/null
+++ b/tfjs/tools/custom_bundle/esm_module_provider_test.ts
@@ -0,0 +1,64 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+import {esmModuleProvider} from './esm_module_provider';
+
+describe('ESM Module Provider', () => {
+  it('importCoreStr', () => {
+    const res = esmModuleProvider.importCoreStr();
+    expect(res).toContain(
+        // tslint:disable-next-line: max-line-length
+        `import {registerKernel, registerGradient} from '@tensorflow/tfjs-core/dist/base'`);
+    expect(res).toContain(
+        `import '@tensorflow/tfjs-core/dist/base_side_effects';`);
+    expect(res).toContain(`export * from '@tensorflow/tfjs-core/dist/base';`);
+  });
+
+  it('importConverterStr', () => {
+    const res = esmModuleProvider.importConverterStr();
+    expect(res).toBe(`export * from '@tensorflow/tfjs-converter';`);
+  });
+
+  it('importBackendStr cpu', () => {
+    const res = esmModuleProvider.importBackendStr('cpu');
+    expect(res).toBe(`export * from '@tensorflow/tfjs-backend-cpu/dist/base';`);
+  });
+
+  it('importBackendStr webgl', () => {
+    const res = esmModuleProvider.importBackendStr('webgl');
+    expect(res).toBe(
+        `export * from '@tensorflow/tfjs-backend-webgl/dist/base';`);
+  });
+
+  it('importKernelStr Max cpu', () => {
+    const res = esmModuleProvider.importKernelStr('Max', 'cpu');
+    expect(res.importStatement).toContain('import {maxConfig as Max_cpu}');
+    expect(res.importStatement)
+        .toContain(`from '@tensorflow/tfjs-backend-cpu/dist/kernels/Max'`);
+
+    expect(res.kernelConfigId).toBe('Max_cpu');
+  });
+
+  it('importGradientConfigStr Max', () => {
+    const res = esmModuleProvider.importGradientConfigStr('Max');
+    expect(res.importStatement).toContain('import {maxGradConfig}');
+    expect(res.importStatement)
+        .toContain(`from '@tensorflow/tfjs-core/dist/gradients/Max_grad'`);
+
+    expect(res.gradConfigId).toBe('maxGradConfig');
+  });
+});
diff --git a/tfjs/tools/custom_bundle/tsconfig.json b/tfjs/tools/custom_bundle/tsconfig.json
new file mode 100644
index 00000000000..a981dfa447b
--- /dev/null
+++ b/tfjs/tools/custom_bundle/tsconfig.json
@@ -0,0 +1,10 @@
+{
+  "extends": "../../tsconfig.test",
+  "include": [
+    "../../tools/"
+  ],
+  "compilerOptions": {
+    "module": "commonjs",
+    "outDir": "../../dist/tools/custom_bundle"
+  }
+}
diff --git a/tfjs/tools/custom_bundle/types.ts b/tfjs/tools/custom_bundle/types.ts
new file mode 100644
index 00000000000..7fb3989b776
--- /dev/null
+++ b/tfjs/tools/custom_bundle/types.ts
@@ -0,0 +1,45 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * 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.
+ * =============================================================================
+ */
+
+export enum SupportedBackends {
+  cpu = 'cpu',
+  webgl = 'webgl'
+}
+export type SupportedBackend = keyof typeof SupportedBackends;
+
+export interface CustomTFJSBundleConfig {
+  entries?: string[];             // paths to javascript files to walk
+  models?: string[];              // paths to model.json files to walk
+  backends?: SupportedBackend[];  // backends to include/use kernels from
+  forwardModeOnly?: boolean;      // whether to drop gradients
+  outputPath: string;             // path to output file
+  kernels?: string[];             // Kernels to include
+}
+
+// Interface for an object that can provide functionality to generate
+// a correct custom module for that build environment (e.g. node vs g3).
+export interface ModuleProvider {
+  importCoreStr: () => string;
+  importConverterStr: () => string;
+  importBackendStr: (backendPkg: string) => string;
+  importKernelStr: (kernelName: string, backend: string) => {
+    importStatement: string, kernelConfigId: string
+  };
+  importGradientConfigStr: (kernelName: string) => {
+    importStatement: string, gradConfigId: string
+  };
+}
diff --git a/tfjs/yarn.lock b/tfjs/yarn.lock
index c8aa0e0d28d..d66381a954b 100644
--- a/tfjs/yarn.lock
+++ b/tfjs/yarn.lock
@@ -975,7 +975,7 @@ ansi-styles@^3.2.1:
   dependencies:
     color-convert "^1.9.0"
 
-ansi-styles@^4.0.0:
+ansi-styles@^4.0.0, ansi-styles@^4.1.0:
   version "4.2.1"
   resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-4.2.1.tgz#90ae75c424d008d2624c5bf29ead3177ebfcf359"
   integrity sha512-9VGjrMsG1vePxcSweQsN20KY/c4zN0h9fLjqAbwbPfahM3t+NL+M9HC8xeXG2I8pX5NoamTGNuomEUFI7fcUjA==
@@ -1001,7 +1001,7 @@ arg@^4.1.0:
   resolved "https://registry.yarnpkg.com/arg/-/arg-4.1.3.tgz#269fc7ad5b8e42cb63c896d5666017261c144089"
   integrity sha512-58S9QDqG0Xx27YwPSt9fJxivjYl432YCwfDMfZ+71RAqUrZef7LrKQZ3LHLOwCS4FLNBplP533Zx895SeOCHvA==
 
-argparse@^1.0.7:
+argparse@^1.0.10, argparse@^1.0.7:
   version "1.0.10"
   resolved "https://registry.yarnpkg.com/argparse/-/argparse-1.0.10.tgz#bcd6791ea5ae09725e17e5ad988134cd40b3d911"
   integrity sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==
@@ -1446,6 +1446,14 @@ chalk@^2.0.0, chalk@^2.3.0, chalk@^2.4.1:
     escape-string-regexp "^1.0.5"
     supports-color "^5.3.0"
 
+chalk@^4.1.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/chalk/-/chalk-4.1.0.tgz#4e14870a618d9e2edd97dd8345fd9d9dc315646a"
+  integrity sha512-qwx12AxXe2Q5xQ43Ac//I6v5aXTipYrSESdOgzrN+9XjgEpyjpKuvSGaN4qE93f7TQTlerQQ8S+EQ0EyDoVL1A==
+  dependencies:
+    ansi-styles "^4.1.0"
+    supports-color "^7.1.0"
+
 chokidar@^3.0.0:
   version "3.4.0"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-3.4.0.tgz#b30611423ce376357c765b9b8f904b9fba3c0be8"
@@ -2305,6 +2313,11 @@ has-flag@^3.0.0:
   resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-3.0.0.tgz#b5d454dc2199ae225699f3467e5a07f3b955bafd"
   integrity sha1-tdRU3CGZriJWmfNGfloH87lVuv0=
 
+has-flag@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-4.0.0.tgz#944771fd9c81c81265c4d6941860da06bb59479b"
+  integrity sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==
+
 has-symbols@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/has-symbols/-/has-symbols-1.0.0.tgz#ba1a8f1af2a0fc39650f5c850367704122063b44"
@@ -4261,6 +4274,13 @@ supports-color@^6.1.0:
   dependencies:
     has-flag "^3.0.0"
 
+supports-color@^7.1.0:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-7.1.0.tgz#68e32591df73e25ad1c4b49108a2ec507962bfd1"
+  integrity sha512-oRSIpR8pxT1Wr2FquTNnGet79b3BWljqOuoW/h4oBhxJ/HUbX5nX6JSruTkvXDCFMwDPvsaTTbvMLKZWSy0R5g==
+  dependencies:
+    has-flag "^4.0.0"
+
 terser@^4.6.2:
   version "4.6.11"
   resolved "https://registry.yarnpkg.com/terser/-/terser-4.6.11.tgz#12ff99fdd62a26de2a82f508515407eb6ccd8a9f"