diff --git a/packages/worker/src/sentry-options.node.test.ts b/packages/worker/src/sentry-options.node.test.ts
index ff3161c7d5..50ede8df4d 100644
--- a/packages/worker/src/sentry-options.node.test.ts
+++ b/packages/worker/src/sentry-options.node.test.ts
@@ -1,5 +1,9 @@
 import { expect, test } from 'vitest'
-import { filterRetryableD1LockSentryEvent } from './sentry-options.ts'
+import {
+	filterRetryableD1LockSentryEvent,
+	filterSentryEvent,
+	filterUserModuleBundlerFailureSentryEvent,
+} from './sentry-options.ts'
 
 test('filterRetryableD1LockSentryEvent drops transient D1 lock contention and keeps other errors', () => {
 	expect(
@@ -21,3 +25,66 @@ test('filterRetryableD1LockSentryEvent drops transient D1 lock contention and ke
 	}
 	expect(filterRetryableD1LockSentryEvent(unrelatedEvent)).toBe(unrelatedEvent)
 })
+
+test('filterUserModuleBundlerFailureSentryEvent drops esbuild failures in caller modules', () => {
+	const userModuleBuildFailure = {
+		exception: {
+			values: [
+				{
+					value:
+						'Build failed with 1 error:\nvirtual:.__kody_root__/entry.ts:11:49: ERROR: Unexpected "^"',
+				},
+			],
+		},
+	}
+	expect(
+		filterUserModuleBundlerFailureSentryEvent(userModuleBuildFailure),
+	).toBeNull()
+	expect(filterSentryEvent(userModuleBuildFailure)).toBeNull()
+
+	const userModuleMessageFailure = {
+		message:
+			'Build failed with 1 error:\nvirtual:.__kody_root__/entry.ts:11:49: ERROR: Unexpected "^"',
+	}
+	expect(
+		filterUserModuleBundlerFailureSentryEvent(userModuleMessageFailure),
+	).toBeNull()
+	expect(filterSentryEvent(userModuleMessageFailure)).toBeNull()
+
+	const platformBuildFailure = {
+		exception: {
+			values: [
+				{
+					value:
+						'Build failed with 1 error:\npackages/worker/src/index.ts:1:0: ERROR: Unexpected "{"',
+				},
+			],
+		},
+	}
+	expect(filterUserModuleBundlerFailureSentryEvent(platformBuildFailure)).toBe(
+		platformBuildFailure,
+	)
+	expect(filterSentryEvent(platformBuildFailure)).toBe(platformBuildFailure)
+
+	const unrelated = {
+		exception: {
+			values: [{ value: 'Execution timed out' }],
+		},
+	}
+	expect(filterUserModuleBundlerFailureSentryEvent(unrelated)).toBe(unrelated)
+	expect(filterSentryEvent(unrelated)).toBe(unrelated)
+})
+
+test('filterSentryEvent still drops retryable D1 lock contention', () => {
+	expect(
+		filterSentryEvent({
+			exception: {
+				values: [
+					{
+						value: 'D1_ERROR: NOSENTRY database is locked: SQLITE_BUSY',
+					},
+				],
+			},
+		}),
+	).toBeNull()
+})
diff --git a/packages/worker/src/sentry-options.ts b/packages/worker/src/sentry-options.ts
index 3ed79cd68c..cad18018d3 100644
--- a/packages/worker/src/sentry-options.ts
+++ b/packages/worker/src/sentry-options.ts
@@ -2,6 +2,13 @@ import { type CloudflareOptions } from '@sentry/cloudflare'
 import { type ErrorEvent } from '@sentry/core'
 import { isRetryableD1LockSentryEvent } from './d1-retry.ts'
 
+function sentryEventMessages(event: ErrorEvent) {
+	return [
+		event.message,
+		...(event.exception?.values?.map((value) => value.value) ?? []),
+	]
+}
+
 /**
  * Shared Sentry options for the Cloudflare Worker and Durable Objects.
  * `dsn` may be undefined when Sentry is not configured (local dev / opt-out).
@@ -11,6 +18,33 @@ export function filterRetryableD1LockSentryEvent(event: ErrorEvent) {
 	return null
 }
 
+/**
+ * Runtime bundling of caller-supplied modules (MCP execute, inline workflows)
+ * puts source under `.__kody_root__/`. When that source is invalid, esbuild
+ * throws `Build failed with … virtual:.__kody_root__/…`. Those are user-module
+ * mistakes, not platform defects — MCP execute already routes them as sandbox
+ * errors, but workflow instrumentation still auto-captures the rethrow.
+ */
+export function isUserModuleBundlerFailureSentryEvent(event: ErrorEvent) {
+	return sentryEventMessages(event).some(
+		(message) =>
+			typeof message === 'string' &&
+			message.includes('Build failed with') &&
+			message.includes('.__kody_root__/'),
+	)
+}
+
+export function filterUserModuleBundlerFailureSentryEvent(event: ErrorEvent) {
+	if (!isUserModuleBundlerFailureSentryEvent(event)) return event
+	return null
+}
+
+export function filterSentryEvent(event: ErrorEvent) {
+	if (filterRetryableD1LockSentryEvent(event) === null) return null
+	if (filterUserModuleBundlerFailureSentryEvent(event) === null) return null
+	return event
+}
+
 export function buildSentryOptions(env: Env): CloudflareOptions {
 	const dsn = env.SENTRY_DSN?.trim()
 	const environment = env.SENTRY_ENVIRONMENT?.trim() || 'development'
@@ -32,7 +66,10 @@ export function buildSentryOptions(env: Env): CloudflareOptions {
 		// application capture paths (for example scheduled_lane_failed) still
 		// forwarded them. These are transient lock-contention errors retried in
 		// app code and should not open or regress Sentry issues.
-		beforeSend: filterRetryableD1LockSentryEvent,
+		//
+		// User-module esbuild failures from inline workflows are similarly
+		// expected caller mistakes; see filterUserModuleBundlerFailureSentryEvent.
+		beforeSend: filterSentryEvent,
 	}
 }