diff --git a/electron/main.ts b/electron/main.ts
index c4f2568d..5da8698d 100644
--- a/electron/main.ts
+++ b/electron/main.ts
@@ -336,7 +336,7 @@ function getExpandedShellPath(): string {
     return [...new Set(allParts)].join(sep);
   } else {
     const basePath = `/usr/local/bin:/opt/homebrew/bin:/usr/bin:/bin`;
-    const raw = `${basePath}:${home}/.npm-global/bin:${home}/.local/bin:${home}/.claude/bin:${shellPath}`;
+    const raw = `${basePath}:${home}/.npm-global/bin:${home}/.bun/bin:${home}/.local/bin:${home}/.claude/bin:${shellPath}`;
     const allParts = raw.split(':').filter(Boolean);
     return [...new Set(allParts)].join(':');
   }
diff --git a/src/lib/claude-client.ts b/src/lib/claude-client.ts
index a8939428..eabce2aa 100644
--- a/src/lib/claude-client.ts
+++ b/src/lib/claude-client.ts
@@ -930,7 +930,7 @@ export function streamClaude(options: ClaudeStreamOptions): ReadableStream<strin
             const detailHint = extraDetail ? `\n\nDetails: ${extraDetail}` : '';
             const hasImages = files && files.some(f => isImageFile(f.type));
             const imageHint = hasImages ? '\n• Provider may not support image/vision input' : '';
-            errorMessage = `Claude Code process exited with an error${providerHint}. This is often caused by:\n• Invalid or missing API Key\n• Incorrect Base URL configuration\n• Network connectivity issues${imageHint}${detailHint}\n\nOriginal error: ${rawMessage}`;
+            errorMessage = `Claude Code process exited with an error${providerHint}. This is often caused by:\n• Invalid or missing API Key\n• Incorrect Base URL configuration\n• Network connectivity issues\n• API provider not activated (check Settings → API Providers and ensure your provider is set as active)${imageHint}${detailHint}\n\nOriginal error: ${rawMessage}`;
           } else if (rawMessage.includes('exited with code')) {
             const providerHint = resolved.provider?.name ? ` (Provider: ${resolved.provider?.name})` : '';
             errorMessage = `Claude Code process crashed unexpectedly${providerHint}.\n\nOriginal error: ${rawMessage}`;
diff --git a/src/lib/db.ts b/src/lib/db.ts
index 35698520..6bba9e4c 100644
--- a/src/lib/db.ts
+++ b/src/lib/db.ts
@@ -1054,6 +1054,9 @@ export function createProvider(data: CreateProviderRequest): ApiProvider {
   const maxRow = db.prepare('SELECT MAX(sort_order) as max_order FROM api_providers').get() as { max_order: number | null };
   const sortOrder = (maxRow.max_order ?? -1) + 1;
 
+  // Activate the new provider only if there is no existing active provider (e.g. first-time onboarding)
+  const hasActive = db.prepare('SELECT 1 FROM api_providers WHERE is_active = 1 LIMIT 1').get();
+
   db.prepare(
     `INSERT INTO api_providers (id, name, provider_type, protocol, base_url, api_key, is_active, sort_order, extra_env, headers_json, env_overrides_json, role_models_json, notes, created_at, updated_at)
      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`
@@ -1064,7 +1067,7 @@ export function createProvider(data: CreateProviderRequest): ApiProvider {
     data.protocol || '',
     data.base_url || '',
     data.api_key || '',
-    0,
+    hasActive ? 0 : 1,
     sortOrder,
     data.extra_env || '{}',
     data.headers_json || '{}',
diff --git a/src/lib/platform.ts b/src/lib/platform.ts
index 0be9860b..5473e1de 100644
--- a/src/lib/platform.ts
+++ b/src/lib/platform.ts
@@ -40,6 +40,7 @@ export function getExtraPathDirs(): string[] {
     '/usr/bin',
     '/bin',
     path.join(home, '.npm-global', 'bin'),
+    path.join(home, '.bun', 'bin'),
     path.join(home, '.nvm', 'current', 'bin'),
     path.join(home, '.local', 'bin'),
     path.join(home, '.claude', 'bin'),
@@ -74,6 +75,7 @@ export function getClaudeCandidatePaths(): string[] {
     '/usr/local/bin/claude',
     '/opt/homebrew/bin/claude',
     path.join(home, '.npm-global', 'bin', 'claude'),
+    path.join(home, '.bun', 'bin', 'claude'),
     path.join(home, '.local', 'bin', 'claude'),
     path.join(home, '.claude', 'bin', 'claude'),
   ];