Fix third-party Anthropic provider connection tests

src/__tests__/unit/error-classifier.test.ts

@@ -0,0 +1,17 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { classifyError } from '../../lib/error-classifier';
+
+describe('error-classifier', () => {
+  it('classifies 503 provider responses as temporarily unavailable', () => {
+    const result = classifyError({
+      error: new Error('HTTP 503: {"error":"Service temporarily unavailable"}'),
+      providerName: 'Third-party Provider',
+    });
+
+    assert.equal(result.category, 'PROVIDER_UNAVAILABLE');
+    assert.equal(result.retryable, true);
+    assert.ok(result.userMessage.includes('Third-party Provider'));
+    assert.ok(result.actionHint.includes('model name mapping'));
+  });
+});

src/__tests__/unit/provider-key-lifecycle.test.ts

@@ -144,6 +144,21 @@ describe('Provider key lifecycle — Codex follow-ups', () => {
       );
     });
 
+    it('connection tests use model mappings before falling back to aliases', () => {
+      assert.ok(
+        source.match(/const testModelName[\s\S]*modelName\.trim\(\)[\s\S]*mapSonnet\.trim\(\)[\s\S]*mapOpus\.trim\(\)[\s\S]*mapHaiku\.trim\(\)/),
+        'test connection should prefer user-entered model mappings over default aliases',
+      );
+      assert.ok(
+        source.match(/modelName:\s*testModelName/),
+        'test request body should send the resolved test model name',
+      );
+      assert.ok(
+        !source.match(/modelName:\s*modelName\s*\|\|\s*undefined/),
+        'test request body should not ignore model mapping fields',
+      );
+    });
+
     it('test button disabled prop references canTest', () => {
       assert.ok(
         source.match(/disabled=\{saving \|\| testing \|\| !canTest\}/),

src/components/settings/PresetConnectDialog.tsx

@@ -132,6 +132,14 @@ export function PresetConnectDialog({
     return false;
   })();
 
+  const testModelName = (() => {
+    if (modelName.trim()) return modelName.trim();
+    if (preset?.fields.includes("model_mapping")) {
+      return mapSonnet.trim() || mapOpus.trim() || mapHaiku.trim() || undefined;
+    }
+    return undefined;
+  })();
+
   const handleTestConnection = async () => {
     // Belt-and-suspenders: the button disabled state already enforces
     // this, but guard here in case something bypasses the UI (keyboard
@@ -155,7 +163,7 @@ export function PresetConnectDialog({
         protocol: preset?.protocol || 'anthropic',
         authStyle: preset?.key === 'anthropic-thirdparty' ? authStyle : (preset?.authStyle || authStyle),
         envOverrides,
-        modelName: modelName || undefined,
+        modelName: testModelName,
         providerName: name || preset?.name,
       };
       if (isEdit && editProvider) {

src/lib/error-classifier.ts

@@ -61,6 +61,7 @@ export type ClaudeErrorCategory =
   | 'AUTH_FORBIDDEN'
   | 'AUTH_STYLE_MISMATCH'
   | 'RATE_LIMITED'
+  | 'PROVIDER_UNAVAILABLE'
   | 'NETWORK_UNREACHABLE'
   | 'ENDPOINT_NOT_FOUND'
   | 'MODEL_NOT_AVAILABLE'
@@ -227,6 +228,15 @@ const ERROR_PATTERNS: ErrorPattern[] = [
     retryable: true,
   },
 
+  // ── Provider temporarily unavailable (503) ──
+  {
+    category: 'PROVIDER_UNAVAILABLE',
+    patterns: ['503', 'service temporarily unavailable', 'service unavailable', 'temporarily unavailable'],
+    userMessage: (ctx) => `Provider is temporarily unavailable${providerHint(ctx)}.`,
+    actionHint: () => 'Retry later. If this happens only during connection testing, check that the model name mapping matches the provider-supported model IDs.',
+    retryable: true,
+  },
+
   // ── Model not available ──
   {
     category: 'MODEL_NOT_AVAILABLE',
@@ -433,8 +443,10 @@ function buildRecoveryActions(category: ClaudeErrorCategory, ctx: ErrorContext):
       actions.push({ label: 'Open Settings', action: 'open_settings' });
       break;
     case 'RATE_LIMITED':
+    case 'PROVIDER_UNAVAILABLE':
       actions.push({ label: 'Retry', action: 'retry' });
       if (meta?.pricingUrl) actions.push({ label: 'Upgrade Plan', url: meta.pricingUrl });
+      if (meta?.docsUrl) actions.push({ label: 'View Docs', url: meta.docsUrl });
       break;
     case 'MODEL_NOT_AVAILABLE':
     case 'ENDPOINT_NOT_FOUND':