diff --git a/package.json b/package.json
index 9006f8c0980..32003d73928 100644
--- a/package.json
+++ b/package.json
@@ -58,6 +58,8 @@
     "integration/*"
   ],
   "devDependencies": {
+    "@microsoft/api-documenter": "7.7.20",
+    "@microsoft/api-extractor": "7.7.13",
     "@types/chai": "4.2.11",
     "@types/chai-as-promised": "7.1.2",
     "@types/long": "4.0.1",
@@ -65,6 +67,8 @@
     "@types/node": "12.12.37",
     "@types/sinon": "9.0.0",
     "@types/sinon-chai": "3.2.4",
+    "@types/tmp": "0.2.0",
+    "@types/yargs": "15.0.4",
     "@typescript-eslint/eslint-plugin": "2.30.0",
     "@typescript-eslint/eslint-plugin-tslint": "2.30.0",
     "@typescript-eslint/parser": "2.30.0",
@@ -132,9 +136,7 @@
     "typescript": "3.8.3",
     "watch": "1.0.2",
     "webpack": "4.43.0",
-    "yargs": "15.3.1",
-    "@microsoft/api-extractor": "7.7.13",
-    "@microsoft/api-documenter": "7.7.20"
+    "yargs": "15.3.1"
   },
   "husky": {
     "hooks": {
diff --git a/packages/firestore/exp/index.d.ts b/packages/firestore/exp/index.d.ts
new file mode 100644
index 00000000000..982b12e255c
--- /dev/null
+++ b/packages/firestore/exp/index.d.ts
@@ -0,0 +1,19 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC
+ *
+ * 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 function foo(): string;
+export function bar(): string;
diff --git a/packages/firestore/exp/index.node.ts b/packages/firestore/exp/index.node.ts
new file mode 100644
index 00000000000..ac36767cfe2
--- /dev/null
+++ b/packages/firestore/exp/index.node.ts
@@ -0,0 +1,18 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC
+ *
+ * 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 { foo, bar } from './src/api/foobar';
diff --git a/packages/firestore/exp/src/api/foobar.ts b/packages/firestore/exp/src/api/foobar.ts
new file mode 100644
index 00000000000..328241108fb
--- /dev/null
+++ b/packages/firestore/exp/src/api/foobar.ts
@@ -0,0 +1,24 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC
+ *
+ * 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 function foo(): string {
+  return bar();
+}
+
+export function bar(): string {
+  return 'bar';
+}
diff --git a/packages/firestore/exp/test/deps/dependencies.json b/packages/firestore/exp/test/deps/dependencies.json
new file mode 100644
index 00000000000..e348f877ca0
--- /dev/null
+++ b/packages/firestore/exp/test/deps/dependencies.json
@@ -0,0 +1,23 @@
+{
+    "bar": {
+        "dependencies": {
+            "functions": [
+                "bar"
+            ],
+            "classes": [],
+            "variables": []
+        },
+        "sizeInBytes": 39
+    },
+    "foo": {
+        "dependencies": {
+            "functions": [
+                "bar",
+                "foo"
+            ],
+            "classes": [],
+            "variables": []
+        },
+        "sizeInBytes": 67
+    }
+}
diff --git a/packages/firestore/exp/test/deps/verify_dependencies.test.ts b/packages/firestore/exp/test/deps/verify_dependencies.test.ts
new file mode 100644
index 00000000000..ffebded12bd
--- /dev/null
+++ b/packages/firestore/exp/test/deps/verify_dependencies.test.ts
@@ -0,0 +1,45 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC
+ *
+ * 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 { expect } from 'chai';
+
+import { extractDependencies } from '../../../../../scripts/exp/extract-deps.helpers';
+
+import * as dependencies from './dependencies.json';
+import * as pkg from '../../../package.json';
+import { forEach } from '../../../src/util/obj';
+
+describe('Dependencies', () => {
+  forEach(dependencies, (api, { dependencies }) => {
+    it(api, () => {
+      return extractDependencies(api, pkg.exp).then(extractedDependencies => {
+        expect(extractedDependencies.classes).to.have.members(
+          dependencies.classes,
+          'for classes'
+        );
+        expect(extractedDependencies.functions).to.have.members(
+          dependencies.functions,
+          'for functions'
+        );
+        expect(extractedDependencies.variables).to.have.members(
+          dependencies.variables,
+          'for variables'
+        );
+      });
+    });
+  });
+});
diff --git a/packages/firestore/externs.json b/packages/firestore/externs.json
index c5c690cc031..d597bfb77a9 100644
--- a/packages/firestore/externs.json
+++ b/packages/firestore/externs.json
@@ -23,8 +23,8 @@
     "packages/webchannel-wrapper/src/index.d.ts",
     "packages/util/dist/src/environment.d.ts",
     "packages/firestore/src/protos/firestore_proto_api.d.ts",
-    "packages/firestore/dist/lib/src/util/error.d.ts",
-    "packages/firestore/dist/lib/src/local/indexeddb_schema.d.ts",
-    "packages/firestore/dist/lib/src/local/shared_client_state_schema.d.ts"
+    "packages/firestore/src/util/error.ts",
+    "packages/firestore/src/local/indexeddb_schema.ts",
+    "packages/firestore/src/local/shared_client_state_schema.ts"
   ]
 }
diff --git a/packages/firestore/package.json b/packages/firestore/package.json
index 665ad2fef68..0635fdf8e46 100644
--- a/packages/firestore/package.json
+++ b/packages/firestore/package.json
@@ -7,15 +7,20 @@
   "description": "The Cloud Firestore component of the Firebase JS SDK.",
   "author": "Firebase <firebase-support@google.com> (https://firebase.google.com/)",
   "scripts": {
-    "prebuild": "tsc -d --downlevelIteration --declarationDir dist/lib --emitDeclarationOnly && tsc -m es2015 --moduleResolution node scripts/*.ts ",
+    "prebuild": "tsc -m es2015 --moduleResolution node scripts/*.ts ",
     "build": "rollup -c rollup.config.es2017.js && rollup -c rollup.config.es5.js",
     "build:deps": "lerna run --scope @firebase/'{app,firestore}' --include-dependencies build",
     "build:console": "node tools/console.build.js",
+    "build:exp": "rollup -c rollup.config.exp.js",
     "predev": "yarn prebuild",
     "dev": "rollup -c -w",
     "lint": "eslint -c .eslintrc.js '**/*.ts' --ignore-path '../../.gitignore'",
     "lint:fix": "eslint --fix -c .eslintrc.js '**/*.ts' --ignore-path '../../.gitignore'",
-    "prettier": "prettier --write '*.ts' '*.js' 'src/**/*.js' 'test/**/*.js' 'src/**/*.ts' 'test/**/*.ts'",
+    "prettier": "prettier --write '*.ts' '*.js' 'exp/**/*.ts' 'src/**/*.js' 'test/**/*.js' 'src/**/*.ts' 'test/**/*.ts'",
+    "pregendeps:exp": "yarn build:exp",
+    "gendeps:exp": "../../scripts/exp/extract-deps.sh --types ./exp/index.d.ts --bundle ./dist/exp/index.js --output ./exp/test/deps/dependencies.json",
+    "pretest:exp": "yarn build:exp",
+    "test:exp":  "TS_NODE_CACHE=NO TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\"}' nyc --reporter lcovonly -- mocha 'exp/test/**/*.test.ts' --file exp/index.node.ts --config ../../config/mocharc.node.js",
     "test": "run-s lint test:all",
     "test:ci": "node ../../scripts/run_tests_in_ci.js",
     "test:all": "run-p test:browser test:travis test:minified",
@@ -34,6 +39,7 @@
   "browser": "dist/index.cjs.js",
   "module": "dist/index.esm.js",
   "esm2017": "dist/index.esm2017.js",
+  "exp": "dist/exp/index.js",
   "license": "Apache-2.0",
   "files": [
     "dist",
diff --git a/packages/firestore/rollup.config.exp.js b/packages/firestore/rollup.config.exp.js
new file mode 100644
index 00000000000..912f2a943a1
--- /dev/null
+++ b/packages/firestore/rollup.config.exp.js
@@ -0,0 +1,52 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC
+ *
+ * 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 typescriptPlugin from 'rollup-plugin-typescript2';
+import typescript from 'typescript';
+
+import { resolveNodeExterns } from './rollup.shared';
+
+import pkg from './package.json';
+
+const defaultPlugins = [
+  typescriptPlugin({
+    typescript,
+    tsconfigOverride: {
+      compilerOptions: {
+        target: 'es2017'
+      }
+    },
+    clean: true
+  })
+];
+
+const nodeBuilds = [
+  {
+    input: './exp/index.node.ts',
+    output: {
+      file: pkg.exp,
+      format: 'es'
+    },
+    plugins: defaultPlugins,
+    external: resolveNodeExterns,
+    treeshake: {
+      tryCatchDeoptimization: false
+    }
+  }
+];
+
+export default [...nodeBuilds];
diff --git a/packages/firestore/scripts/extract-api.ts b/packages/firestore/scripts/extract-api.ts
index 7e520a4dfbc..49dee323669 100644
--- a/packages/firestore/scripts/extract-api.ts
+++ b/packages/firestore/scripts/extract-api.ts
@@ -32,6 +32,17 @@ function extractIdentifiersFromNodeAndChildren(
   );
 }
 
+/** Generates the "d.ts" content for `fileName`. */
+function extractTypeDeclaration(fileName: string): string {
+  let result: string;
+  const compilerOptions = { declaration: true, emitDeclarationOnly: true };
+  const host = ts.createCompilerHost(compilerOptions);
+  host.writeFile = (_: string, contents: string) => (result = contents);
+  const program = ts.createProgram([fileName], compilerOptions, host);
+  program.emit();
+  return result!;
+}
+
 /**
  * Traverses TypeScript type definition files and returns the list of referenced
  * identifiers.
@@ -41,12 +52,21 @@ export function extractPublicIdentifiers(filePaths: string[]): Set<string> {
 
   for (const filePath of filePaths) {
     const contents = fs.readFileSync(filePath, { encoding: 'UTF-8' });
-    const sourceFile = ts.createSourceFile(
+    let sourceFile = ts.createSourceFile(
       filePath,
       contents,
       ts.ScriptTarget.ES2015
     );
 
+    if (!sourceFile.isDeclarationFile) {
+      const dtsSource = extractTypeDeclaration(filePath);
+      sourceFile = ts.createSourceFile(
+        filePath.replace('.ts', '.d.ts'),
+        dtsSource,
+        ts.ScriptTarget.ES2015
+      );
+    }
+
     const identifiers = new Set<string>();
     ts.forEachChild(sourceFile, (childNode: ts.Node) =>
       extractIdentifiersFromNodeAndChildren(childNode, identifiers)
diff --git a/scripts/exp/extract-deps.helpers.ts b/scripts/exp/extract-deps.helpers.ts
new file mode 100644
index 00000000000..4df429b8102
--- /dev/null
+++ b/scripts/exp/extract-deps.helpers.ts
@@ -0,0 +1,128 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC
+ *
+ * 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 * as tmp from 'tmp';
+import * as path from 'path';
+import * as fs from 'fs';
+import * as rollup from 'rollup';
+import * as terser from 'terser';
+import * as ts from 'typescript';
+
+/** Contains a list of members by type. */
+export type MemberList = {
+  classes: string[];
+  functions: string[];
+  variables: string[];
+};
+/** Contains the dependencies and the size of their code for a single export. */
+export type ExportData = { dependencies: MemberList; sizeInBytes: number };
+
+/**
+ * This functions builds a simple JS app that only depends on the provided
+ * export. It then uses Rollup to gather all top-level classes and functions
+ * that that the export depends on.
+ *
+ * @param exportName The name of the export to verify
+ * @param jsBundle The file name of the source bundle that contains the export
+ * @return A list of dependencies for the given export
+ */
+export async function extractDependencies(
+  exportName: string,
+  jsBundle: string
+): Promise<MemberList> {
+  const { dependencies } = await extractDependenciesAndSize(
+    exportName,
+    jsBundle
+  );
+  return dependencies;
+}
+
+/**
+ * Helper for extractDependencies that extracts the dependencies and the size
+ * of the minified build.
+ */
+export async function extractDependenciesAndSize(
+  exportName: string,
+  jsBundle: string
+): Promise<ExportData> {
+  const input = tmp.fileSync().name + '.js';
+  const output = tmp.fileSync().name + '.js';
+
+  // JavaScript content that exports a single API from the bundle
+  const beforeContent = `export { ${exportName} } from '${path.resolve(
+    jsBundle
+  )}';`;
+  fs.writeFileSync(input, beforeContent);
+
+  // Run Rollup on the JavaScript above to produce a tree-shaken build
+  const bundle = await rollup.rollup({
+    input,
+    external: id => id.startsWith('@firebase/')
+  });
+  await bundle.write({ file: output, format: 'es' });
+
+  const dependencies = extractDeclarations(output);
+
+  // Extract size of minified build
+  const afterContent = fs.readFileSync(output, 'utf-8');
+  const { code } = terser.minify(afterContent, {
+    output: {
+      comments: false
+    },
+    mangle: false,
+    compress: false
+  });
+
+  fs.unlinkSync(input);
+  fs.unlinkSync(output);
+
+  return { dependencies, sizeInBytes: Buffer.byteLength(code!, 'utf-8') };
+}
+
+/**
+ * Extracts all function, class and variable declarations using the TypeScript
+ * compiler API.
+ */
+export function extractDeclarations(jsFile: string): MemberList {
+  const program = ts.createProgram([jsFile], { allowJs: true });
+  const sourceFile = program.getSourceFile(jsFile);
+  if (!sourceFile) {
+    throw new Error('Failed to parse file: ' + jsFile);
+  }
+
+  const declarations: MemberList = {
+    functions: [],
+    classes: [],
+    variables: []
+  };
+  ts.forEachChild(sourceFile, node => {
+    if (ts.isFunctionDeclaration(node)) {
+      declarations.functions.push(node.name!.text);
+    } else if (ts.isClassDeclaration(node)) {
+      declarations.classes.push(node.name!.text);
+    } else if (ts.isVariableDeclaration(node)) {
+      declarations.variables.push(node.name!.getText());
+    }
+  });
+
+  // Sort to ensure stable output
+  declarations.functions.sort();
+  declarations.classes.sort();
+  declarations.variables.sort();
+
+  return declarations;
+}
diff --git a/scripts/exp/extract-deps.sh b/scripts/exp/extract-deps.sh
new file mode 100755
index 00000000000..410fe120f15
--- /dev/null
+++ b/scripts/exp/extract-deps.sh
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# Copyright 2020 Google Inc.
+#
+# 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.
+
+# extract-deps --- Invokes extract-deps using TS_NODE
+
+set -o nounset
+set -o errexit
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+NPM_BIN_DIR="$(npm bin)"
+TSNODE="$NPM_BIN_DIR/ts-node"
+GENERATE_DEPS_JS="$DIR/extract-deps.ts"
+
+export TS_NODE_CACHE=NO 
+export TS_NODE_COMPILER_OPTIONS='{"module":"commonjs"}' 
+export TS_NODE_PROJECT="$DIR/../../config/tsconfig.base.json"
+
+$TSNODE $GENERATE_DEPS_JS "$@"
diff --git a/scripts/exp/extract-deps.ts b/scripts/exp/extract-deps.ts
new file mode 100644
index 00000000000..4a32d3f6f3c
--- /dev/null
+++ b/scripts/exp/extract-deps.ts
@@ -0,0 +1,71 @@
+/**
+ * @license
+ * Copyright 2020 Google LLC
+ *
+ * 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 * as fs from 'fs';
+import * as path from 'path';
+import * as yargs from 'yargs';
+import {
+  ExportData,
+  extractDependenciesAndSize,
+  extractDeclarations,
+  MemberList
+} from './extract-deps.helpers';
+
+// Small command line app that builds a JSON file with a list of the
+// dependencies for each individual exported type. This can then be used to
+// verify dependencies in tree-shakeable SDKs.
+
+const argv = yargs.options({
+  types: {
+    type: 'string',
+    demandOption: true,
+    desc: 'The location of the index.d.ts file that describes the Public API'
+  },
+  bundle: {
+    type: 'string',
+    demandOption: true,
+    desc:
+      'The location of transpiled JavaScript bundle that contains all code for the SDK'
+  },
+  output: {
+    type: 'string',
+    demandOption: true,
+    desc: 'The location to write the JSON output to'
+  }
+}).argv;
+
+async function buildJson(
+  publicApi: MemberList,
+  jsFile: string
+): Promise<string> {
+  const result: { [key: string]: ExportData } = {};
+  for (const exp of publicApi.classes) {
+    result[exp] = await extractDependenciesAndSize(exp, jsFile);
+  }
+  for (const exp of publicApi.functions) {
+    result[exp] = await extractDependenciesAndSize(exp, jsFile);
+  }
+  for (const exp of publicApi.variables) {
+    result[exp] = await extractDependenciesAndSize(exp, jsFile);
+  }
+  return JSON.stringify(result, null, 4);
+}
+
+const publicApi = extractDeclarations(path.resolve(argv.types));
+buildJson(publicApi, path.resolve(argv.bundle)).then(json => {
+  fs.writeFileSync(path.resolve(argv.output), json);
+});
diff --git a/yarn.lock b/yarn.lock
index 6a0bb5a6e2a..1591ae97d02 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2255,11 +2255,28 @@
   resolved "https://registry.npmjs.org/@types/sinonjs__fake-timers/-/sinonjs__fake-timers-6.0.1.tgz#681df970358c82836b42f989188d133e218c458e"
   integrity sha512-yYezQwGWty8ziyYLdZjwxyMb0CZR49h8JALHGrxjQHWlqGgc8kLdHEgWrgL0uZ29DMvEVBDnHU2Wg36zKSIUtA==
 
+"@types/tmp@0.2.0":
+  version "0.2.0"
+  resolved "https://registry.npmjs.org/@types/tmp/-/tmp-0.2.0.tgz#e3f52b4d7397eaa9193592ef3fdd44dc0af4298c"
+  integrity sha512-flgpHJjntpBAdJD43ShRosQvNC0ME97DCfGvZEDlAThQmnerRXrLbX6YgzRBQCZTthET9eAWFAMaYP0m0Y4HzQ==
+
 "@types/tough-cookie@*":
   version "4.0.0"
   resolved "https://registry.npmjs.org/@types/tough-cookie/-/tough-cookie-4.0.0.tgz#fef1904e4668b6e5ecee60c52cc6a078ffa6697d"
   integrity sha512-I99sngh224D0M7XgW1s120zxCt3VYQ3IQsuw3P3jbq5GG4yc79+ZjyKznyOGIQrflfylLgcfekeZW/vk0yng6A==
 
+"@types/yargs-parser@*":
+  version "15.0.0"
+  resolved "https://registry.npmjs.org/@types/yargs-parser/-/yargs-parser-15.0.0.tgz#cb3f9f741869e20cce330ffbeb9271590483882d"
+  integrity sha512-FA/BWv8t8ZWJ+gEOnLLd8ygxH/2UFbAvgEonyfN6yWGLKc7zVjbpl2Y4CTjid9h2RfgPP6SEt6uHwEOply00yw==
+
+"@types/yargs@15.0.4":
+  version "15.0.4"
+  resolved "https://registry.npmjs.org/@types/yargs/-/yargs-15.0.4.tgz#7e5d0f8ca25e9d5849f2ea443cf7c402decd8299"
+  integrity sha512-9T1auFmbPZoxHz0enUFlUuKRy3it01R+hlggyVUMtnCTQRunsQYifnSGb8hET4Xo8yiC0o0r1paW3ud5+rbURg==
+  dependencies:
+    "@types/yargs-parser" "*"
+
 "@types/yauzl@^2.9.1":
   version "2.9.1"
   resolved "https://registry.npmjs.org/@types/yauzl/-/yauzl-2.9.1.tgz#d10f69f9f522eef3cf98e30afb684a1e1ec923af"