diff --git a/spec/fixtures/sources/commonjs-params/index.js b/spec/fixtures/sources/commonjs-params/index.js
new file mode 100644
index 000000000..d038a2f77
--- /dev/null
+++ b/spec/fixtures/sources/commonjs-params/index.js
@@ -0,0 +1,21 @@
+const functions = require("../../../../src/index");
+const functionsv2 = require("../../../../src/v2/index");
+const { defineString } = require("../../../../src/v2/params");
+
+defineString("FOO");
+
+exports.v1http = functions.https.onRequest((req, resp) => {
+    resp.status(200).send("PASS");
+});
+
+exports.v1callable = functions.https.onCall(() => {
+    return "PASS";
+});
+
+exports.v2http = functionsv2.https.onRequest((req, resp) => {
+    resp.status(200).send("PASS");
+});
+
+exports.v2callable = functionsv2.https.onCall(() => {
+    return "PASS";
+});
diff --git a/spec/fixtures/sources/commonjs-params/package.json b/spec/fixtures/sources/commonjs-params/package.json
new file mode 100644
index 000000000..91f8c11da
--- /dev/null
+++ b/spec/fixtures/sources/commonjs-params/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "commonjs-params"
+}
diff --git a/spec/runtime/loader.spec.ts b/spec/runtime/loader.spec.ts
index 9994557c4..bb959a3cb 100644
--- a/spec/runtime/loader.spec.ts
+++ b/spec/runtime/loader.spec.ts
@@ -310,6 +310,11 @@ describe('loadStack', () => {
           },
         },
       },
+      {
+        name: 'has params',
+        modulePath: './spec/fixtures/sources/commonjs-params',
+        expected: { ...expected, params: [{ name: 'FOO', type: 'string' }] },
+      },
     ];
 
     for (const tc of testcases) {
diff --git a/src/runtime/loader.ts b/src/runtime/loader.ts
index de31eefd3..4dd4b41d2 100644
--- a/src/runtime/loader.ts
+++ b/src/runtime/loader.ts
@@ -28,6 +28,8 @@ import {
   ManifestStack,
 } from './manifest';
 
+import * as params from '../v2/params';
+
 /**
  * Dynamically load import function to prevent TypeScript from
  * transpiling into a require.
@@ -112,9 +114,13 @@ export async function loadStack(functionsDir: string): Promise<ManifestStack> {
 
   extractStack(mod, endpoints, requiredAPIs);
 
-  return {
+  const stack: ManifestStack = {
     endpoints,
     specVersion: 'v1alpha1',
     requiredAPIs: mergeRequiredAPIs(requiredAPIs),
   };
+  if (params.declaredParams.length > 0) {
+    stack.params = params.declaredParams.map((p) => p.toSpec());
+  }
+  return stack;
 }
diff --git a/src/runtime/manifest.ts b/src/runtime/manifest.ts
index 562d1a52f..d63088303 100644
--- a/src/runtime/manifest.ts
+++ b/src/runtime/manifest.ts
@@ -20,6 +20,8 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
+import { ParamSpec } from '../v2/params/types';
+
 /**
  * An definition of a function as appears in the Manifest.
  */
@@ -87,6 +89,7 @@ export interface ManifestRequiredAPI {
  */
 export interface ManifestStack {
   specVersion: 'v1alpha1';
+  params?: ParamSpec[];
   requiredAPIs: ManifestRequiredAPI[];
   endpoints: Record<string, ManifestEndpoint>;
 }
diff --git a/src/v2/params/index.ts b/src/v2/params/index.ts
index bf45e8c45..3f8a080b6 100644
--- a/src/v2/params/index.ts
+++ b/src/v2/params/index.ts
@@ -24,6 +24,7 @@
  * @hidden
  * @alpha
  */
+
 import {
   BooleanParam,
   FloatParam,
diff --git a/src/v2/params/types.ts b/src/v2/params/types.ts
index 9612dc8dc..fc898c15c 100644
--- a/src/v2/params/types.ts
+++ b/src/v2/params/types.ts
@@ -28,16 +28,13 @@ export interface ParamSpec<T = unknown> {
   default?: T;
   label?: string;
   description?: string;
-  valueType?: ParamValueType;
+  type: ParamValueType;
 }
 
-export type ParamOptions<T = unknown> = Omit<
-  ParamSpec<T>,
-  'name' | 'valueType'
->;
+export type ParamOptions<T = unknown> = Omit<ParamSpec<T>, 'name' | 'type'>;
 
 export class Param<T = unknown> {
-  static valueType: ParamValueType = 'string';
+  static type: ParamValueType = 'string';
 
   constructor(readonly name: string, readonly options: ParamOptions<T> = {}) {}
 
@@ -61,7 +58,7 @@ export class Param<T = unknown> {
     const out: ParamSpec = {
       name: this.name,
       ...this.options,
-      valueType: (this.constructor as typeof Param).valueType,
+      type: (this.constructor as typeof Param).type,
     };
     if (this.options.default && typeof this.options.default !== 'string') {
       out.default = (this.options.default as
@@ -78,7 +75,7 @@ export class StringParam extends Param<string> {
 }
 
 export class IntParam extends Param<number> {
-  static valueType: ParamValueType = 'int';
+  static type: ParamValueType = 'int';
 
   get value(): number {
     const intVal = parseInt(
@@ -97,7 +94,7 @@ export class IntParam extends Param<number> {
 }
 
 export class FloatParam extends Param<number> {
-  static valueType: ParamValueType = 'float';
+  static type: ParamValueType = 'float';
 
   get value(): number {
     const floatVal = parseFloat(
@@ -115,7 +112,7 @@ export class FloatParam extends Param<number> {
 }
 
 export class BooleanParam extends Param {
-  static valueType: ParamValueType = 'boolean';
+  static type: ParamValueType = 'boolean';
 
   get value(): boolean {
     const lowerVal = (
@@ -137,7 +134,7 @@ export class BooleanParam extends Param {
 }
 
 export class ListParam extends Param<string[]> {
-  static valueType: ParamValueType = 'list';
+  static type: ParamValueType = 'list';
 
   get value(): string[] {
     return typeof this.rawValue === 'string'
@@ -148,7 +145,7 @@ export class ListParam extends Param<string[]> {
   toSpec(): ParamSpec<string> {
     const out: ParamSpec = {
       name: this.name,
-      valueType: 'list',
+      type: 'list',
       ...this.options,
     };
     if (this.options.default && this.options.default.length > 0) {
@@ -160,7 +157,7 @@ export class ListParam extends Param<string[]> {
 }
 
 export class JSONParam<T = any> extends Param<T> {
-  static valueType: ParamValueType = 'json';
+  static type: ParamValueType = 'json';
 
   get value(): T {
     if (this.rawValue) {