diff --git a/src/base/assert.test.ts b/src/base/assert.test.ts
new file mode 100644
index 0000000000..1448198385
--- /dev/null
+++ b/src/base/assert.test.ts
@@ -0,0 +1,91 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { assert, setAssertReporter } from '@/base/assert'
+
+describe('assert', () => {
+  let consoleErrorSpy: ReturnType<typeof vi.spyOn>
+
+  beforeEach(() => {
+    consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {})
+  })
+
+  afterEach(() => {
+    vi.restoreAllMocks()
+    vi.unstubAllEnvs()
+    setAssertReporter(null)
+  })
+
+  it('does nothing when condition is true', () => {
+    expect(() => assert(true, 'should not throw')).not.toThrow()
+    expect(consoleErrorSpy).not.toHaveBeenCalled()
+  })
+
+  it('logs console.error when condition is false', () => {
+    vi.stubEnv('DEV', false)
+    assert(false, 'test message')
+    expect(consoleErrorSpy).toHaveBeenCalledWith(
+      '[Assertion failed]: test message'
+    )
+  })
+
+  it('throws in DEV mode when condition is false', () => {
+    vi.stubEnv('DEV', true)
+    const reporter = vi.fn()
+    setAssertReporter(reporter)
+    expect(() => assert(false, 'dev error')).toThrow(
+      '[Assertion failed]: dev error'
+    )
+    expect(consoleErrorSpy).toHaveBeenCalledWith(
+      '[Assertion failed]: dev error'
+    )
+    expect(reporter).not.toHaveBeenCalled()
+  })
+
+  it('does not throw in non-DEV mode when condition is false', () => {
+    vi.stubEnv('DEV', false)
+    expect(() => assert(false, 'non-dev error')).not.toThrow()
+  })
+
+  it('calls registered reporter in non-DEV mode with formatted message', () => {
+    vi.stubEnv('DEV', false)
+    const reporter = vi.fn()
+    setAssertReporter(reporter)
+    assert(false, 'reporter message')
+    expect(reporter).toHaveBeenCalledWith(
+      '[Assertion failed]: reporter message'
+    )
+  })
+
+  it('does not call reporter when condition is true', () => {
+    vi.stubEnv('DEV', false)
+    const reporter = vi.fn()
+    setAssertReporter(reporter)
+    assert(true, 'no call')
+    expect(reporter).not.toHaveBeenCalled()
+  })
+
+  it('handles null reporter gracefully in non-DEV mode', () => {
+    vi.stubEnv('DEV', false)
+    setAssertReporter(null)
+    expect(() => assert(false, 'null reporter')).not.toThrow()
+    expect(consoleErrorSpy).toHaveBeenCalledWith(
+      '[Assertion failed]: null reporter'
+    )
+  })
+
+  it('swallows reporter exceptions in non-DEV mode', () => {
+    vi.stubEnv('DEV', false)
+    const reporter = vi.fn(() => {
+      throw new Error('reporter blew up')
+    })
+    setAssertReporter(reporter)
+    expect(() => assert(false, 'safe under reporter failure')).not.toThrow()
+    expect(consoleErrorSpy).toHaveBeenCalledWith(
+      '[Assertion failed]: safe under reporter failure'
+    )
+    expect(consoleErrorSpy).toHaveBeenCalledWith(
+      '[Assertion reporter failed]',
+      expect.any(Error)
+    )
+  })
+})
diff --git a/src/base/assert.ts b/src/base/assert.ts
new file mode 100644
index 0000000000..829285ffde
--- /dev/null
+++ b/src/base/assert.ts
@@ -0,0 +1,36 @@
+type AssertReporter = (message: string) => void
+
+let reporter: AssertReporter | null = null
+
+/**
+ * Register a reporter for assertion failures in non-DEV environments.
+ * Called once at app startup by platform/ or higher layers to wire in
+ * Sentry, toast notifications, etc.
+ */
+export function setAssertReporter(fn: AssertReporter | null): void {
+  reporter = fn
+}
+
+/**
+ * Centralized invariant assertion.
+ *
+ * - Always: console.error
+ * - DEV: throws (surfaces bugs immediately)
+ * - Otherwise: delegates to registered reporter (Sentry, toast, etc.)
+ */
+export function assert(condition: unknown, message: string): asserts condition {
+  if (condition) return
+
+  const formatted = `[Assertion failed]: ${message}`
+  console.error(formatted)
+
+  if (import.meta.env.DEV) {
+    throw new Error(formatted)
+  }
+
+  try {
+    reporter?.(formatted)
+  } catch (error) {
+    console.error('[Assertion reporter failed]', error)
+  }
+}
diff --git a/src/main.ts b/src/main.ts
index a32242468c..7898779cf5 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -11,6 +11,7 @@ import Tooltip from 'primevue/tooltip'
 import { createApp } from 'vue'
 import { VueFire, VueFireAuth } from 'vuefire'
 
+import { setAssertReporter } from '@/base/assert'
 import { getFirebaseConfig } from '@/config/firebase'
 import {
   configValueOrDefault,
@@ -18,6 +19,8 @@ import {
 } from '@/platform/remoteConfig/remoteConfig'
 import '@/lib/litegraph/public/css/litegraph.css'
 import router from '@/router'
+import { isDesktop, isNightly } from '@/platform/distribution/types'
+import { useToastStore } from '@/platform/updates/common/toastStore'
 import { useBootstrapStore } from '@/stores/bootstrapStore'
 
 import App from './App.vue'
@@ -81,6 +84,22 @@ Sentry.init({
         defaultIntegrations: false
       })
 })
+// Assertion reporter receives pre-formatted messages (with "[Assertion failed]: " prefix).
+// Strings here are intentionally not i18n'd: they're developer/nightly diagnostics,
+// not user-facing in stable releases.
+setAssertReporter((message) => {
+  if (isDesktop) {
+    Sentry.captureMessage(message, { level: 'warning' })
+  }
+  if (isNightly) {
+    useToastStore(pinia).add({
+      severity: 'warn',
+      summary: 'Assertion failed',
+      detail: message
+    })
+  }
+})
+
 app.directive('tooltip', Tooltip)
 app
   .use(router)
diff --git a/src/scripts/changeTracker.test.ts b/src/scripts/changeTracker.test.ts
index 5513d83915..53724fb52d 100644
--- a/src/scripts/changeTracker.test.ts
+++ b/src/scripts/changeTracker.test.ts
@@ -2,6 +2,12 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import type { ComfyWorkflowJSON } from '@/platform/workflow/validation/schemas/workflowSchema'
 
+const mockAssert = vi.hoisted(() => vi.fn())
+
+vi.mock('@/base/assert', () => ({
+  assert: mockAssert
+}))
+
 const mockNodeOutputStore = vi.hoisted(() => ({
   snapshotOutputs: vi.fn(() => ({})),
   restoreOutputs: vi.fn()
@@ -151,13 +157,17 @@ describe('ChangeTracker', () => {
         expect(app.rootGraph.serialize).not.toHaveBeenCalled()
       })
 
-      it('is a no-op and logs error when called on inactive tracker', () => {
+      it('is a no-op and calls assert when called on inactive tracker', () => {
         const tracker = createTracker()
         mockWorkflowStore.activeWorkflow = { changeTracker: {} }
 
         tracker.captureCanvasState()
 
         expect(app.rootGraph.serialize).not.toHaveBeenCalled()
+        expect(mockAssert).toHaveBeenCalledWith(
+          false,
+          expect.stringContaining('captureCanvasState')
+        )
       })
     })
 
@@ -254,7 +264,7 @@ describe('ChangeTracker', () => {
       expect(mockNodeOutputStore.snapshotOutputs).toHaveBeenCalled()
     })
 
-    it('is a full no-op when called on inactive tracker', () => {
+    it('is a full no-op and calls assert when called on inactive tracker', () => {
       const tracker = createTracker()
       mockWorkflowStore.activeWorkflow = { changeTracker: {} }
 
@@ -262,6 +272,10 @@ describe('ChangeTracker', () => {
 
       expect(app.rootGraph.serialize).not.toHaveBeenCalled()
       expect(mockNodeOutputStore.snapshotOutputs).not.toHaveBeenCalled()
+      expect(mockAssert).toHaveBeenCalledWith(
+        false,
+        expect.stringContaining('deactivate')
+      )
     })
   })
 
diff --git a/src/scripts/changeTracker.ts b/src/scripts/changeTracker.ts
index da7d861405..54312ea239 100644
--- a/src/scripts/changeTracker.ts
+++ b/src/scripts/changeTracker.ts
@@ -1,9 +1,8 @@
-import * as Sentry from '@sentry/vue'
 import _ from 'es-toolkit/compat'
 
+import { assert } from '@/base/assert'
 import type { CanvasPointerEvent } from '@/lib/litegraph/src/litegraph'
 import { LGraphCanvas, LiteGraph } from '@/lib/litegraph/src/litegraph'
-import { isDesktop } from '@/platform/distribution/types'
 import type { ComfyWorkflow } from '@/platform/workflow/management/stores/workflowStore'
 import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
 import type { ComfyWorkflowJSON } from '@/platform/workflow/validation/schemas/workflowSchema'
@@ -24,23 +23,20 @@ function isActiveTracker(tracker: ChangeTracker): boolean {
   return useWorkflowStore().activeWorkflow?.changeTracker === tracker
 }
 
+const reportedInactiveCalls = new Set<string>()
+
 /**
- * Report a ChangeTracker method being called on an inactive tracker —
- * a lifecycle violation that usually indicates stale extension state or
- * an incorrect call ordering.
+ * Report a ChangeTracker method being called on an inactive tracker.
+ * Deduplicates per method+workflow per session to avoid signal noise on hot paths.
  */
 function reportInactiveTrackerCall(method: string, workflowPath: string) {
-  console.warn(`${method}() called on inactive tracker for: ${workflowPath}`)
-
-  if (isDesktop) {
-    Sentry.captureMessage(
-      `ChangeTracker.${method}() called on inactive tracker`,
-      {
-        level: 'warning',
-        tags: { workflow: workflowPath }
-      }
-    )
-  }
+  const key = `${method}:${workflowPath}`
+  if (reportedInactiveCalls.has(key)) return
+  reportedInactiveCalls.add(key)
+  assert(
+    false,
+    `ChangeTracker.${method}() called on inactive tracker for: ${workflowPath}`
+  )
 }
 
 export class ChangeTracker {