diff --git a/src/utils/hooks/image-analysis-backend-resolver.ts b/src/utils/hooks/image-analysis-backend-resolver.ts
index 229d6e11..8bef4ad6 100644
--- a/src/utils/hooks/image-analysis-backend-resolver.ts
+++ b/src/utils/hooks/image-analysis-backend-resolver.ts
@@ -8,6 +8,7 @@ import {
   mapExternalProviderName,
 } from '../../cliproxy/provider-capabilities';
 import { getProviderCatalog, supportsNativeImageInput } from '../../cliproxy/model-catalog';
+import { buildCliproxyProviderPath } from '../../cliproxy/config/provider-route';
 import { extractProviderFromPathname } from '../../cliproxy/ai-providers/model-id-normalizer';
 import type { CliproxyBridgeMetadata } from '../../api/services/profile-types';
 import type { Settings } from '../../types/config';
@@ -251,6 +252,12 @@ function getRuntimePath(backendId: string | null): string | null {
     return null;
   }
 
+  if (isCLIProxyProvider(backendId)) {
+    // Claude-compatible traffic and the original backend route at the
+    // CLIProxy root; /api/provider/<id> scoped routes are Plus-only.
+    return buildCliproxyProviderPath(backendId) || null;
+  }
+
   return `/api/provider/${backendId}`;
 }
 
diff --git a/tests/unit/utils/hooks/image-analysis-runtime-status-config-default.test.ts b/tests/unit/utils/hooks/image-analysis-runtime-status-config-default.test.ts
index 3f859652..e3909c8f 100644
--- a/tests/unit/utils/hooks/image-analysis-runtime-status-config-default.test.ts
+++ b/tests/unit/utils/hooks/image-analysis-runtime-status-config-default.test.ts
@@ -106,7 +106,9 @@ describe('resolveImageAnalysisRuntimeStatus config default', () => {
     expect(status.backendId).toBe('claude');
     expect(status.resolutionSource).toBe('profile-backend');
     expect(status.model).toBe('claude-haiku-4-5-20251001');
-    expect(status.runtimePath).toBe('/api/provider/claude');
+    // Claude-compatible traffic routes at the CLIProxy root; the scoped
+    // /api/provider/claude path is not part of the canonical route helper.
+    expect(status.runtimePath).toBeNull();
     expect(status.effectiveRuntimeMode).toBe('cliproxy-image-analysis');
   });
 });
diff --git a/tests/unit/utils/hooks/image-analysis-runtime-status-original-backend-route.test.ts b/tests/unit/utils/hooks/image-analysis-runtime-status-original-backend-route.test.ts
new file mode 100644
index 00000000..4e9a63bc
--- /dev/null
+++ b/tests/unit/utils/hooks/image-analysis-runtime-status-original-backend-route.test.ts
@@ -0,0 +1,111 @@
+import { mkdtempSync, mkdirSync, rmSync, writeFileSync } from 'fs';
+import { tmpdir } from 'os';
+import { join } from 'path';
+import { afterEach, beforeEach, describe, expect, it } from 'bun:test';
+
+/**
+ * Regression (#1703): the original CLIProxy backend only serves the root
+ * /v1/messages route. Image analysis used to build
+ * /api/provider/<id>/v1/messages unconditionally, which 404s on original.
+ * The default backend is original, so the default-config path must resolve
+ * a null runtimePath (root route) for CLIProxy providers.
+ */
+describe('resolveImageAnalysisRuntimeStatus original backend route', () => {
+  let tmpHome = '';
+  let previousCcsHome: string | undefined;
+
+  beforeEach(() => {
+    tmpHome = mkdtempSync(join(tmpdir(), 'ccs-image-analysis-original-route-'));
+    const ccsDir = join(tmpHome, '.ccs');
+    mkdirSync(ccsDir, { recursive: true });
+
+    const settingsPath = join(ccsDir, 'deepseek.settings.json');
+    writeFileSync(
+      settingsPath,
+      JSON.stringify(
+        {
+          env: {
+            ANTHROPIC_BASE_URL: 'https://api.deepseek.com/anthropic',
+            ANTHROPIC_MODEL: 'deepseek-v4-pro',
+          },
+        },
+        null,
+        2
+      ) + '\n'
+    );
+
+    writeFileSync(
+      join(ccsDir, 'config.yaml'),
+      [
+        'version: 14',
+        'profiles:',
+        '  deepseek:',
+        '    type: api',
+        `    settings: ${settingsPath}`,
+        'image_analysis:',
+        '  enabled: true',
+        '  timeout: 60',
+        '  provider_models:',
+        '    gemini: gemini-2.5-flash',
+        '  fallback_backend: gemini',
+        '  profile_backends:',
+        '    deepseek: gemini',
+        '',
+      ].join('\n')
+    );
+
+    previousCcsHome = process.env.CCS_HOME;
+    process.env.CCS_HOME = tmpHome;
+  });
+
+  afterEach(() => {
+    if (previousCcsHome === undefined) {
+      delete process.env.CCS_HOME;
+    } else {
+      process.env.CCS_HOME = previousCcsHome;
+    }
+
+    if (tmpHome) {
+      rmSync(tmpHome, { recursive: true, force: true });
+    }
+  });
+
+  it('resolves the root runtime path for the original backend', async () => {
+    const { resolveImageAnalysisRuntimeStatus } = await import(
+      '../../../../src/utils/hooks/image-analysis-runtime-status'
+    );
+
+    const status = await resolveImageAnalysisRuntimeStatus(
+      {
+        profileName: 'deepseek',
+        profileType: 'settings',
+      },
+      undefined,
+      {
+        checkRemoteProxy: async () => ({ reachable: true }),
+        fetchRemoteAuthStatus: async () => [{ provider: 'gemini', authenticated: true }],
+        getProxyTarget: () => ({
+          host: '100.64.0.1',
+          port: 8317,
+          protocol: 'http',
+          isRemote: true,
+        }),
+        initializeAccounts: () => {},
+        getAuthStatus: () => ({
+          provider: 'gemini',
+          authenticated: true,
+          tokenDir: join(tmpHome, 'auth'),
+          tokenFiles: [],
+          accounts: [],
+          defaultAccount: undefined,
+        }),
+        isCliproxyRunning: async () => true,
+      }
+    );
+
+    expect(status.backendId).toBe('gemini');
+    expect(status.resolutionSource).toBe('profile-backend');
+    // Root route: the hook appends /v1/messages directly to the proxy base.
+    expect(status.runtimePath).toBeNull();
+  });
+});
diff --git a/tests/unit/utils/hooks/image-analysis-runtime-status-plus-backend-route.test.ts b/tests/unit/utils/hooks/image-analysis-runtime-status-plus-backend-route.test.ts
new file mode 100644
index 00000000..6d23d83b
--- /dev/null
+++ b/tests/unit/utils/hooks/image-analysis-runtime-status-plus-backend-route.test.ts
@@ -0,0 +1,110 @@
+import { mkdtempSync, mkdirSync, rmSync, writeFileSync } from 'fs';
+import { tmpdir } from 'os';
+import { join } from 'path';
+import { afterEach, beforeEach, describe, expect, it } from 'bun:test';
+
+/**
+ * Counterpart to the original-backend route regression (#1703): with
+ * cliproxy.backend: plus, non-Claude providers keep their scoped
+ * /api/provider/<id> routes for image analysis.
+ */
+describe('resolveImageAnalysisRuntimeStatus plus backend route', () => {
+  let tmpHome = '';
+  let previousCcsHome: string | undefined;
+
+  beforeEach(() => {
+    tmpHome = mkdtempSync(join(tmpdir(), 'ccs-image-analysis-plus-route-'));
+    const ccsDir = join(tmpHome, '.ccs');
+    mkdirSync(ccsDir, { recursive: true });
+
+    const settingsPath = join(ccsDir, 'deepseek.settings.json');
+    writeFileSync(
+      settingsPath,
+      JSON.stringify(
+        {
+          env: {
+            ANTHROPIC_BASE_URL: 'https://api.deepseek.com/anthropic',
+            ANTHROPIC_MODEL: 'deepseek-v4-pro',
+          },
+        },
+        null,
+        2
+      ) + '\n'
+    );
+
+    writeFileSync(
+      join(ccsDir, 'config.yaml'),
+      [
+        'version: 14',
+        'profiles:',
+        '  deepseek:',
+        '    type: api',
+        `    settings: ${settingsPath}`,
+        'cliproxy:',
+        '  backend: plus',
+        'image_analysis:',
+        '  enabled: true',
+        '  timeout: 60',
+        '  provider_models:',
+        '    gemini: gemini-2.5-flash',
+        '  fallback_backend: gemini',
+        '  profile_backends:',
+        '    deepseek: gemini',
+        '',
+      ].join('\n')
+    );
+
+    previousCcsHome = process.env.CCS_HOME;
+    process.env.CCS_HOME = tmpHome;
+  });
+
+  afterEach(() => {
+    if (previousCcsHome === undefined) {
+      delete process.env.CCS_HOME;
+    } else {
+      process.env.CCS_HOME = previousCcsHome;
+    }
+
+    if (tmpHome) {
+      rmSync(tmpHome, { recursive: true, force: true });
+    }
+  });
+
+  it('keeps the scoped provider route for the plus backend', async () => {
+    const { resolveImageAnalysisRuntimeStatus } = await import(
+      '../../../../src/utils/hooks/image-analysis-runtime-status'
+    );
+
+    const status = await resolveImageAnalysisRuntimeStatus(
+      {
+        profileName: 'deepseek',
+        profileType: 'settings',
+      },
+      undefined,
+      {
+        checkRemoteProxy: async () => ({ reachable: true }),
+        fetchRemoteAuthStatus: async () => [{ provider: 'gemini', authenticated: true }],
+        getProxyTarget: () => ({
+          host: '100.64.0.1',
+          port: 8317,
+          protocol: 'http',
+          isRemote: true,
+        }),
+        initializeAccounts: () => {},
+        getAuthStatus: () => ({
+          provider: 'gemini',
+          authenticated: true,
+          tokenDir: join(tmpHome, 'auth'),
+          tokenFiles: [],
+          accounts: [],
+          defaultAccount: undefined,
+        }),
+        isCliproxyRunning: async () => true,
+      }
+    );
+
+    expect(status.backendId).toBe('gemini');
+    expect(status.resolutionSource).toBe('profile-backend');
+    expect(status.runtimePath).toBe('/api/provider/gemini');
+  });
+});