diff --git a/src/modules/creators/creator-holders.controller.ts b/src/modules/creators/creator-holders.controller.ts
index bdb91a0..03983bb 100644
--- a/src/modules/creators/creator-holders.controller.ts
+++ b/src/modules/creators/creator-holders.controller.ts
@@ -12,6 +12,7 @@ import { attachTimestampHeader } from '../../utils/timestamp-headers.utils';
 import { parsePublicQuery } from '../../utils/public-query-parse.utils';
 import { buildOffsetPaginationMeta } from '../../utils/pagination.utils';
 import { handleCreatorParamNotFound } from '../creator/creator.utils';
+import { parseCreatorId } from '../../utils/creator-id.utils';
 
 /**
  * Controller for GET /api/v1/creators/:id/holders
@@ -26,8 +27,8 @@ import { handleCreatorParamNotFound } from '../creator/creator.utils';
  */
 export const httpGetCreatorHolders: AsyncController = async (req, res, next) => {
    try {
-      const rawId = req.params['id'];
-      const id = typeof rawId === 'string' ? rawId : String(rawId ?? '');
+      const rawId = req.params.id;
+      const creatorId = parseCreatorId(Array.isArray(rawId) ? rawId[0] : rawId);
 
       const parsed = parsePublicQuery(CreatorHoldersQuerySchema, req.query, {
          debugContext: 'creator-holders-query',
@@ -37,7 +38,7 @@ export const httpGetCreatorHolders: AsyncController = async (req, res, next) =>
          return sendValidationError(res, 'Invalid query parameters', parsed.details);
       }
 
-      const creator = await findCreatorByIdOrHandle(id);
+      const creator = await findCreatorByIdOrHandle(String(creatorId));
       if (!handleCreatorParamNotFound(res, creator)) return;
 
       const [holders, total] = await fetchCreatorHolders(creator.id, parsed.data);
diff --git a/src/modules/creators/creators.controllers.ts b/src/modules/creators/creators.controllers.ts
index 46c87e1..e7f5b11 100644
--- a/src/modules/creators/creators.controllers.ts
+++ b/src/modules/creators/creators.controllers.ts
@@ -20,6 +20,7 @@ import {
    incrementFilterParseError,
    type FilterParseErrorCategory,
 } from '../../utils/filter-parse-metrics.utils';
+import { parseCreatorId } from '../../utils/creator-id.utils';
 
 /**
  * Controller for GET /api/v1/creators
@@ -101,16 +102,10 @@ function categorizeParseError(
  */
 export const httpGetCreatorStats: AsyncController = async (req, res, next) => {
    try {
-      const { id } = req.params;
+      const rawId = req.params.id;
+      const _creatorId = parseCreatorId(Array.isArray(rawId) ? rawId[0] : rawId);
 
-      // Validate creator ID format (basic validation)
-      if (!id || typeof id !== 'string') {
-         return sendValidationError(res, 'Invalid creator ID', [
-            { field: 'id', message: 'Creator ID must be a valid string' },
-         ]);
-      }
-
-      // TODO: Fetch actual creator metrics from database/service
+      // TODO: Fetch actual creator metrics from database/service using _creatorId
       // For now, return placeholder data
       const placeholderMetrics = {
          holderCount: 0,
diff --git a/src/modules/webhooks/webhook-signature.middleware.ts b/src/modules/webhooks/webhook-signature.middleware.ts
index 1f85f3a..5155494 100644
--- a/src/modules/webhooks/webhook-signature.middleware.ts
+++ b/src/modules/webhooks/webhook-signature.middleware.ts
@@ -6,6 +6,7 @@ import { ErrorCode } from '../../constants/error.constants';
 import { prisma } from '../../utils/prisma.utils';
 import { logger } from '../../utils/logger.utils';
 import { createHash } from 'crypto';
+import { parseCreatorId } from '../../utils/creator-id.utils';
 
 export interface WalletSignedRequest extends Request {
   walletAddress?: string;
@@ -72,10 +73,12 @@ export function requireWalletSignature() {
       return;
     }
 
-    const rawCreatorId = req.params.id;
-    const creatorId = Array.isArray(rawCreatorId) ? rawCreatorId[0] : rawCreatorId;
-    if (!creatorId) {
-      sendError(res, 400, ErrorCode.BAD_REQUEST, 'Missing creator ID in path');
+    let creatorId: string;
+    try {
+      const rawId = req.params.id;
+      creatorId = String(parseCreatorId(Array.isArray(rawId) ? rawId[0] : rawId));
+    } catch {
+      sendError(res, 400, ErrorCode.BAD_REQUEST, 'Creator ID must be a positive integer');
       return;
     }
 
diff --git a/src/utils/creator-id.utils.ts b/src/utils/creator-id.utils.ts
new file mode 100644
index 0000000..f0172f3
--- /dev/null
+++ b/src/utils/creator-id.utils.ts
@@ -0,0 +1,25 @@
+import { validationError } from '../middlewares/error.middleware';
+
+const POSITIVE_INTEGER_RE = /^\d+$/;
+
+export function parseCreatorId(raw: string): number {
+  if (!raw || typeof raw !== 'string') {
+    throw validationError('Creator ID is required');
+  }
+
+  const trimmed = raw.trim();
+  if (!trimmed) {
+    throw validationError('Creator ID is required');
+  }
+
+  if (!POSITIVE_INTEGER_RE.test(trimmed)) {
+    throw validationError('Creator ID must be a positive integer');
+  }
+
+  const parsed = Number.parseInt(trimmed, 10);
+  if (parsed <= 0 || !Number.isFinite(parsed)) {
+    throw validationError('Creator ID must be a positive integer');
+  }
+
+  return parsed;
+}
diff --git a/src/utils/test/creator-id.utils.test.ts b/src/utils/test/creator-id.utils.test.ts
new file mode 100644
index 0000000..bb510eb
--- /dev/null
+++ b/src/utils/test/creator-id.utils.test.ts
@@ -0,0 +1,58 @@
+import { parseCreatorId } from '../creator-id.utils';
+import { ApiError } from '../../middlewares/error.middleware';
+
+describe('parseCreatorId', () => {
+  it('parses a valid positive integer string', () => {
+    expect(parseCreatorId('42')).toBe(42);
+    expect(parseCreatorId('1')).toBe(1);
+    expect(parseCreatorId('999999')).toBe(999999);
+  });
+
+  it('parses a trimmed integer string', () => {
+    expect(parseCreatorId('  42  ')).toBe(42);
+  });
+
+  it('throws a 400 error for a float string', () => {
+    expect(() => parseCreatorId('3.14')).toThrow(ApiError);
+    expect(() => parseCreatorId('3.14')).toThrow('Creator ID must be a positive integer');
+  });
+
+  it('throws a 400 error for a negative number', () => {
+    expect(() => parseCreatorId('-5')).toThrow(ApiError);
+    expect(() => parseCreatorId('-5')).toThrow('Creator ID must be a positive integer');
+  });
+
+  it('throws a 400 error for a non-numeric string', () => {
+    expect(() => parseCreatorId('abc')).toThrow(ApiError);
+    expect(() => parseCreatorId('abc')).toThrow('Creator ID must be a positive integer');
+  });
+
+  it('throws a 400 error for an empty string', () => {
+    expect(() => parseCreatorId('')).toThrow(ApiError);
+    expect(() => parseCreatorId('')).toThrow('Creator ID is required');
+  });
+
+  it('throws a 400 error for a whitespace-only string', () => {
+    expect(() => parseCreatorId('   ')).toThrow(ApiError);
+    expect(() => parseCreatorId('   ')).toThrow('Creator ID is required');
+  });
+
+  it('throws a 400 error for a string with trailing non-digits', () => {
+    expect(() => parseCreatorId('42abc')).toThrow(ApiError);
+    expect(() => parseCreatorId('42abc')).toThrow('Creator ID must be a positive integer');
+  });
+
+  it('throws a 400 error for zero', () => {
+    expect(() => parseCreatorId('0')).toThrow(ApiError);
+    expect(() => parseCreatorId('0')).toThrow('Creator ID must be a positive integer');
+  });
+
+  it('sets statusCode 400 on the thrown error', () => {
+    try {
+      parseCreatorId('not-a-number');
+    } catch (error) {
+      expect(error).toBeInstanceOf(ApiError);
+      expect((error as ApiError).statusCode).toBe(400);
+    }
+  });
+});