config_corruption_improvement.diff

diff --git a/src/commands/settings/show/index.ts b/src/commands/settings/show/index.ts
index 2a5115d..fe2804c 100644
--- a/src/commands/settings/show/index.ts
+++ b/src/commands/settings/show/index.ts
@@ -15,12 +15,17 @@ export class SettingsShowHandler {
         errors: []
       };
     } catch (error: any) {
+      // Determine if this is a config parsing error
+      const errorType = error instanceof SyntaxError || error.message.includes('JSON') || error.message.includes('parse')
+        ? 'CONFIG_PARSE_ERROR'
+        : 'CONFIG_LOAD_ERROR';
+
       return {
         status: 'error',
         data: null,
         message: error.message,
         errors: [{
-          type: 'CONFIG_LOAD_ERROR',
+          type: errorType,
           message: error.message,
           timestamp: new Date().toISOString()
         }]
diff --git a/src/commands/system/doctor.ts b/src/commands/system/doctor.ts
index 09c9e84..1b3402d 100644
--- a/src/commands/system/doctor.ts
+++ b/src/commands/system/doctor.ts
@@ -12,6 +12,7 @@ interface DoctorCheck {
   name: string;
   status: 'ok' | 'warning' | 'error';
   message?: string;
+  fixHint?: string;
 }

 export class SystemDoctorHandler implements CommandHandler {
@@ -75,20 +76,31 @@ async function checkConfig(): Promise<DoctorCheck> {
       return {
         name: 'config',
         status: 'error',
-        message: 'Missing API base URL in configuration'
+        message: 'Missing API base URL in configuration',
+        fixHint: 'Run "nexus settings set --key apiBaseUrl --value <your-api-url>" to set the API base URL'
       };
     }
-
+
     return {
       name: 'config',
       status: 'ok',
-      message: 'Configuration loaded successfully'
+      message: 'Configuration loaded successfully',
+      fixHint: 'System configuration is valid'
     };
   } catch (error: any) {
+    // Check if this is a config parsing error
+    const isParseError = error instanceof SyntaxError || error.message.toLowerCase().includes('json') || error.message.toLowerCase().includes('parse');
+    const message = isParseError
+      ? `Configuration parsing error: ${error.message}`
+      : `Configuration error: ${error.message}`;
+
     return {
       name: 'config',
       status: 'error',
-      message: `Configuration error: ${error.message}`
+      message,
+      fixHint: isParseError
+        ? 'Configuration file syntax error. Check ~/.nexus/config.json for proper JSON formatting, or run "rm ~/.nexus/config.json" to reset configuration'
+        : 'Check your configuration file at ~/.nexus/config.json for syntax errors'
     };
   }
 }
@@ -111,20 +123,23 @@ async function checkAPIConnectivity(): Promise<DoctorCheck> {
       return {
         name: 'api',
         status: 'ok',
-        message: 'API connectivity established'
+        message: 'API connectivity established',
+        fixHint: 'API is accessible and responding correctly'
       };
     } else {
       return {
         name: 'api',
         status: 'warning',
-        message: `API returned status ${response.status}`
+        message: `API returned status ${response.status}`,
+        fixHint: `Check API server status, received HTTP ${response.status} response`
       };
     }
   } catch (error: any) {
     return {
       name: 'api',
       status: 'warning',
-      message: `API connectivity failed: ${error.message}`
+      message: `API connectivity failed: ${error.message}`,
+      fixHint: 'Verify API server is running and accessible at the configured URL'
     };
   }
 }
@@ -137,10 +152,11 @@ async function checkAuthToken(): Promise<DoctorCheck> {
       return {
         name: 'auth',
         status: 'warning',
-        message: 'No authentication token set'
+        message: 'No authentication token set',
+        fixHint: 'Run "nexus auth login" to authenticate with the API server'
       };
     }
-
+
     // Check if token is valid by attempting to decode it (basic check)
     // JWT tokens have 3 parts separated by dots
     const parts = config.authToken.split('.');
@@ -148,10 +164,11 @@ async function checkAuthToken(): Promise<DoctorCheck> {
       return {
         name: 'auth',
         status: 'error',
-        message: 'Authentication token format is invalid'
+        message: 'Authentication token format is invalid',
+        fixHint: 'Re-authenticate using "nexus auth login" to get a valid token'
       };
     }
-
+
     // Try to use the token with an API request
     const client = new APIClient();
     // Use one of the existing methods that would require authentication
@@ -161,20 +178,23 @@ async function checkAuthToken(): Promise<DoctorCheck> {
       return {
         name: 'auth',
         status: 'ok',
-        message: 'Authentication token is valid'
+        message: 'Authentication token is valid',
+        fixHint: 'Authentication token is valid and working correctly'
       };
     } else {
       return {
         name: 'auth',
         status: 'error',
-        message: 'Authentication token appears to be invalid or expired'
+        message: 'Authentication token appears to be invalid or expired',
+        fixHint: 'Re-authenticate using "nexus auth login" to get a new token'
       };
     }
   } catch (error: any) {
     return {
       name: 'auth',
       status: 'error',
-      message: `Authentication check failed: ${error.message}`
+      message: `Authentication check failed: ${error.message}`,
+      fixHint: 'Check authentication setup, run "nexus auth login" to authenticate'
     };
   }
 }
@@ -191,10 +211,11 @@ async function checkConfigFilePermissions(): Promise<DoctorCheck> {
       return {
         name: 'permissions',
         status: 'error',
-        message: 'Configuration directory does not exist or is not writable'
+        message: 'Configuration directory does not exist or is not writable',
+        fixHint: 'Create the directory ~/.nexus and ensure it is writable: "mkdir -p ~/.nexus && chmod 755 ~/.nexus"'
       };
     }
-
+
     // Check if config file exists and is readable/writable
     try {
       await fs.access(configPath, fs.constants.F_OK | fs.constants.R_OK | fs.constants.W_OK);
@@ -206,21 +227,24 @@ async function checkConfigFilePermissions(): Promise<DoctorCheck> {
         return {
           name: 'permissions',
           status: 'error',
-          message: 'Configuration file cannot be created in directory'
+          message: 'Configuration file cannot be created in directory',
+          fixHint: 'Check permissions on the ~/.nexus directory'
         };
       }
     }
-
+
     return {
       name: 'permissions',
       status: 'ok',
-      message: 'Configuration file permissions are appropriate'
+      message: 'Configuration file permissions are appropriate',
+      fixHint: 'Configuration file permissions are correctly set'
     };
   } catch (error: any) {
     return {
       name: 'permissions',
       status: 'error',
-      message: `Permission check failed: ${error.message}`
+      message: `Permission check failed: ${error.message}`,
+      fixHint: 'Check file permissions for the ~/.nexus directory and configuration file'
     };
   }
 }
@@ -243,20 +267,23 @@ async function checkParity(): Promise<DoctorCheck> {
       return {
         name: 'parity',
         status: 'ok',
-        message: 'File system parity check passed'
+        message: 'File system parity check passed',
+        fixHint: 'File system read/write operations are working correctly'
       };
     } else {
       return {
         name: 'parity',
         status: 'error',
-        message: 'File system parity check failed - read/write inconsistency'
+        message: 'File system parity check failed - read/write inconsistency',
+        fixHint: 'Check disk space and file system for errors'
       };
     }
   } catch (error: any) {
     return {
       name: 'parity',
       status: 'error',
-      message: `Parity check failed: ${error.message}`
+      message: `Parity check failed: ${error.message}`,
+      fixHint: 'Check disk space and file system for errors'
     };
   }
 }
\ No newline at end of file
diff --git a/src/state/config-store.ts b/src/state/config-store.ts
index 55b71f7..60e2622 100644
--- a/src/state/config-store.ts
+++ b/src/state/config-store.ts
@@ -79,6 +79,20 @@ export async function loadConfig(): Promise<Config> {
       const defaultConfig = getDefaultConfig();
       await saveConfig(defaultConfig);
       return defaultConfig;
+    } else if (error instanceof SyntaxError) {
+      // JSON parsing error - config file is corrupted
+      console.error(`Config file corrupted: ${error.message}`);
+      // Return default config but log the issue
+      const defaultConfig = getDefaultConfig();
+      // Try to backup the corrupted config
+      try {
+        const backupPath = configPath + '.backup';
+        await fs.copyFile(configPath, backupPath);
+        console.error(`Corrupted config backed up to: ${backupPath}`);
+      } catch (backupError) {
+        console.error(`Failed to backup corrupted config: ${backupError.message}`);
+      }
+      return defaultConfig;
     } else {
       // Other error occurred, log and return defaults
       console.error(`Error reading config file: ${error.message}`);
diff --git a/src/utils/formatters.ts b/src/utils/formatters.ts
index 7dce5f1..b7bc5b0 100644
--- a/src/utils/formatters.ts
+++ b/src/utils/formatters.ts
@@ -46,7 +46,28 @@ function loadConfigSync(): any {

     if (fs.existsSync(configPath)) {
       const configContent = fs.readFileSync(configPath, 'utf-8');
-      return JSON.parse(configContent);
+      try {
+        return JSON.parse(configContent);
+      } catch (parseError) {
+        // Log the parsing error for debugging
+        console.error(`Config file corrupted: ${parseError.message}`);
+        console.error(`Config path: ${configPath}`);
+
+        // Try to backup the corrupted config
+        try {
+          const backupPath = configPath + '.backup';
+          fs.copyFileSync(configPath, backupPath);
+          console.error(`Corrupted config backed up to: ${backupPath}`);
+        } catch (backupError) {
+          console.error(`Failed to backup corrupted config: ${backupError.message}`);
+        }
+
+        // Return default config
+        return {
+          outputMode: 'pretty',
+          showBanner: true
+        };
+      }
     } else {
       // Return default config if file doesn't exist
       return {
diff --git a/src/utils/hints.ts b/src/utils/hints.ts
index 865a243..dee2b1f 100644
--- a/src/utils/hints.ts
+++ b/src/utils/hints.ts
@@ -34,6 +34,10 @@ export const hints: Hint[] = [
   {
     errorType: 'MISSING_AI_SESSION_CONTEXT',
     message: "Tip: Use 'nexus ai session create' to start an AI session."
+  },
+  {
+    errorType: 'CONFIG_PARSE_ERROR',
+    message: "Configuration file is corrupted. Run 'rm ~/.nexus/config.json' to reset configuration, or manually fix the JSON syntax in the config file."
   }
 ];