diff --git a/src/cli.ts b/src/cli.ts
index 520394c1..ea6536ac 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -483,21 +483,29 @@ program
 program
   .command('web')
   .description('Start the web interface')
+  .option('-H, --host <host>', 'Host to bind to', process.env.CODEMAN_HOST || '127.0.0.1')
   .option('-p, --port <port>', 'Port to listen on (env: CODEMAN_PORT)', process.env.CODEMAN_PORT || '3000')
   .option('--https', 'Enable HTTPS with self-signed certificate (only needed for remote access, not localhost)')
   .option('--title-hostname <hostname>', 'Override the hostname shown in the browser title')
+  .option(
+    '--allow-unauthenticated-network',
+    'Allow non-loopback web access without CODEMAN_PASSWORD (dangerous; terminal control is exposed)'
+  )
   .action(async (options) => {
     const { startWebServer } = await import('./web/server.js');
+    const host = options.host;
     const port = parseInt(options.port, 10);
     const https = !!options.https;
     const titleHostname = options.titleHostname;
+    const allowUnauthenticatedNetwork = !!options.allowUnauthenticatedNetwork;
     const protocol = https ? 'https' : 'http';
+    const displayHost = host === '0.0.0.0' ? 'localhost' : host;
 
-    console.log(chalk.cyan(`Starting Codeman web interface on port ${port}${https ? ' (HTTPS)' : ''}...`));
+    console.log(chalk.cyan(`Starting Codeman web interface on ${displayHost}:${port}${https ? ' (HTTPS)' : ''}...`));
 
     try {
-      const server = await startWebServer(port, https, false, titleHostname);
-      console.log(chalk.green(`\n✓ Web interface running at ${protocol}://localhost:${port}`));
+      const server = await startWebServer(port, https, false, host, titleHostname, allowUnauthenticatedNetwork);
+      console.log(chalk.green(`\n✓ Web interface running at ${protocol}://${displayHost}:${port}`));
       if (https) {
         console.log(chalk.yellow('  Note: Accept the self-signed certificate in your browser on first visit'));
       }
diff --git a/src/web/server.ts b/src/web/server.ts
index ad94e517..95eebb90 100644
--- a/src/web/server.ts
+++ b/src/web/server.ts
@@ -42,6 +42,7 @@ import { execSync } from 'node:child_process';
 import { hostname as getHostname } from 'node:os';
 import { dataPath } from '../config/instance.js';
 import { EventEmitter } from 'node:events';
+import { isIP } from 'node:net';
 import { Session, type BackgroundTask } from '../session.js';
 import type { ClaudeMode, SessionState } from '../types.js';
 import { RespawnController, RespawnConfig } from '../respawn-controller.js';
@@ -122,6 +123,26 @@ import {
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 
+const EXPLICIT_TRUE_VALUES = new Set(['1', 'true', 'yes', 'on']);
+
+function isExplicitlyEnabled(value: string | undefined): boolean {
+  return value !== undefined && EXPLICIT_TRUE_VALUES.has(value.trim().toLowerCase());
+}
+
+function isLoopbackBindHost(host: string): boolean {
+  const normalized = host
+    .trim()
+    .toLowerCase()
+    .replace(/^\[(.*)\]$/, '$1');
+  if (normalized === 'localhost' || normalized === '::1' || normalized === '0:0:0:0:0:0:0:1') {
+    return true;
+  }
+  if (isIP(normalized) === 4 && normalized.startsWith('127.')) {
+    return true;
+  }
+  return normalized.startsWith('::ffff:127.');
+}
+
 // Bounded, predictable shape for SSE client identifiers: alphanumerics, `_`, `-`.
 // Length range covers crypto.randomUUID() (36 chars) plus any short stable IDs,
 // while capping growth of `sseClientsById` and blocking pathological inputs.
@@ -191,6 +212,7 @@ export class WebServer extends EventEmitter {
   private sse: SseStreamManager;
   private store = getStore();
   private port: number;
+  private host: string;
   private https: boolean;
   private testMode: boolean;
   private mux: TerminalMultiplexer;
@@ -232,6 +254,10 @@ export class WebServer extends EventEmitter {
   private pushStore: PushSubscriptionStore = new PushSubscriptionStore();
   private teamWatcher: TeamWatcher = new TeamWatcher();
   private _orchestratorLoop: import('../orchestrator-loop.js').OrchestratorLoop | null = null;
+  private readonly titleHostname: string;
+  private readonly windowTitle: string;
+  private readonly indexHtmlTemplate: string;
+  private readonly allowUnauthenticatedNetwork: boolean;
   private _pasteImageGcStop: (() => void) | null = null;
   private _eventLoopMonitor: EventLoopMonitorHandle | null = null;
   private teamWatcherHandlers: {
@@ -240,15 +266,22 @@ export class WebServer extends EventEmitter {
     teamRemoved: (config: unknown) => void;
     taskUpdated: (data: unknown) => void;
   } | null = null;
-  private readonly titleHostname: string;
-  private readonly windowTitle: string;
-  private readonly indexHtmlTemplate: string;
-  constructor(port: number = 3000, https: boolean = false, testMode: boolean = false, titleHostname?: string) {
+  constructor(
+    port: number = 3000,
+    https: boolean = false,
+    testMode: boolean = false,
+    host: string = '127.0.0.1',
+    titleHostname?: string,
+    allowUnauthenticatedNetwork: boolean = false
+  ) {
     super();
     this.setMaxListeners(0);
+    this.host = host;
     this.port = port;
     this.https = https;
     this.testMode = testMode;
+    this.allowUnauthenticatedNetwork =
+      allowUnauthenticatedNetwork || isExplicitlyEnabled(process.env.CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK);
     this.titleHostname = titleHostname || getHostname();
     this.windowTitle = `codeman:${this.titleHostname}`;
     this.indexHtmlTemplate = readFileSync(join(__dirname, 'public', 'index.html'), 'utf-8');
@@ -1646,6 +1679,13 @@ export class WebServer extends EventEmitter {
   }
 
   async start(): Promise<void> {
+    if (!isLoopbackBindHost(this.host) && !process.env.CODEMAN_PASSWORD && !this.allowUnauthenticatedNetwork) {
+      throw new Error(
+        'Refusing to start Codeman on a non-loopback host without CODEMAN_PASSWORD. ' +
+          'Set CODEMAN_PASSWORD or explicitly allow unauthenticated network access.'
+      );
+    }
+
     await this.setupRoutes();
 
     const lifecycleLog = getLifecycleLog();
@@ -1672,19 +1712,23 @@ export class WebServer extends EventEmitter {
       this._eventLoopMonitor = startEventLoopMonitor();
     }
 
-    await this.app.listen({ port: this.port, host: '0.0.0.0' });
+    await this.app.listen({ port: this.port, host: this.host });
     const protocol = this.https ? 'https' : 'http';
-    console.log(`Codeman web interface running at ${protocol}://localhost:${this.port}`);
+    const displayHost = this.host === '0.0.0.0' ? 'localhost' : this.host;
+    console.log(`Codeman web interface running at ${protocol}://${displayHost}:${this.port}`);
 
-    // Security warning: server binds to 0.0.0.0 (all interfaces) — warn if no auth configured
-    if (!process.env.CODEMAN_PASSWORD) {
+    if (!isLoopbackBindHost(this.host) && !process.env.CODEMAN_PASSWORD && this.allowUnauthenticatedNetwork) {
       console.warn('\n⚠  WARNING: No CODEMAN_PASSWORD set — server is accessible without authentication.');
       console.warn('   Anyone on your network can access and control Claude sessions.');
-      console.warn('   Set CODEMAN_PASSWORD environment variable to enable auth.\n');
+      console.warn(
+        '   This was explicitly allowed by --allow-unauthenticated-network or CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK.\n'
+      );
     }
 
     // Set API URL for child processes (MCP server, spawned sessions)
-    process.env.CODEMAN_API_URL = `${protocol}://localhost:${this.port}`;
+    const apiHost =
+      this.host === '0.0.0.0' || this.host === 'localhost' || this.host === '::1' ? '127.0.0.1' : this.host;
+    process.env.CODEMAN_API_URL = `${protocol}://${apiHost}:${this.port}`;
 
     // Start scheduled runs cleanup timer
     this.cleanup.setInterval(
@@ -2176,9 +2220,11 @@ export async function startWebServer(
   port: number = 3000,
   https: boolean = false,
   testMode: boolean = false,
-  titleHostname?: string
+  host: string = '127.0.0.1',
+  titleHostname?: string,
+  allowUnauthenticatedNetwork: boolean = false
 ): Promise<WebServer> {
-  const server = new WebServer(port, https, testMode, titleHostname);
+  const server = new WebServer(port, https, testMode, host, titleHostname, allowUnauthenticatedNetwork);
   await server.start();
   return server;
 }
diff --git a/test/auth-security.test.ts b/test/auth-security.test.ts
index db3ed2d1..70a0241c 100644
--- a/test/auth-security.test.ts
+++ b/test/auth-security.test.ts
@@ -3,12 +3,12 @@
  * 1. Timing-safe password comparison (timingSafeEqual)
  * 2. Hook event endpoint restricted to localhost
  * 3. Session cookie TTL refresh on access
- * 4. Startup warning when no password configured
+ * 4. Startup fails closed when network-bound without auth
  * 5. SSE client limit enforcement
  * 6. Logout endpoint invalidates session
  * 7. Settings schema rejects unknown fields
  *
- * Port: 3160 (auth tests), 3161 (no-auth tests)
+ * Port: 3160 (auth tests), 3161 (loopback no-auth tests), 3162 (network override tests)
  */
 import { describe, it, expect, beforeAll, afterAll } from 'vitest';
 import { WebServer } from '../src/web/server.js';
@@ -16,6 +16,7 @@ import { SettingsUpdateSchema } from '../src/web/schemas.js';
 
 const AUTH_PORT = 3160;
 const NOAUTH_PORT = 3161;
+const NETWORK_OVERRIDE_PORT = 3162;
 const TEST_USER = 'admin';
 const TEST_PASS = 'test-password-12345';
 
@@ -220,7 +221,7 @@ describe('Settings Schema Security', () => {
 
   it('should enforce tunnelEnabled as boolean', () => {
     const result = SettingsUpdateSchema.safeParse({
-      tunnelEnabled: 'yes',  // truthy string — should be rejected
+      tunnelEnabled: 'yes', // truthy string — should be rejected
     });
     expect(result.success).toBe(false);
   });
@@ -264,40 +265,69 @@ describe('Settings Schema Security', () => {
     expect(validResult.success).toBe(true);
 
     const invalidResult = SettingsUpdateSchema.safeParse({
-      nice: { enabled: true, niceValue: 100 },  // Out of range
+      nice: { enabled: true, niceValue: 100 }, // Out of range
     });
     expect(invalidResult.success).toBe(false);
   });
 });
 
-describe('No-Auth Server Warning', () => {
+describe('No-Auth Server Startup Policy', () => {
   let server: WebServer;
-  let consoleWarnSpy: string[] = [];
-  const originalWarn = console.warn;
 
   beforeAll(async () => {
     delete process.env.CODEMAN_PASSWORD;
     delete process.env.CODEMAN_USERNAME;
-    consoleWarnSpy = [];
-    console.warn = (...args: unknown[]) => {
-      consoleWarnSpy.push(args.map(String).join(' '));
-    };
-    server = new WebServer(NOAUTH_PORT, false, true);
+    delete process.env.CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK;
+    server = new WebServer(NOAUTH_PORT, false, true, '127.0.0.1');
     await server.start();
   });
 
   afterAll(async () => {
-    console.warn = originalWarn;
+    delete process.env.CODEMAN_PASSWORD;
+    delete process.env.CODEMAN_USERNAME;
+    delete process.env.CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK;
     await server.stop();
   });
 
-  it('should warn when no CODEMAN_PASSWORD is set', () => {
-    const hasWarning = consoleWarnSpy.some(msg => msg.includes('No CODEMAN_PASSWORD set'));
-    expect(hasWarning).toBe(true);
-  });
-
-  it('should allow requests without auth when no password configured', async () => {
+  it('allows loopback requests without auth when no password is configured', async () => {
     const res = await fetch(`http://localhost:${NOAUTH_PORT}/api/status`);
     expect(res.status).toBe(200);
   });
+
+  it('rejects non-loopback startup without a password or explicit override', async () => {
+    const networkServer = new WebServer(0, false, true, '0.0.0.0');
+
+    await expect(networkServer.start()).rejects.toThrow(/CODEMAN_PASSWORD/);
+
+    await networkServer.stop();
+  });
+
+  it('allows non-loopback startup when CODEMAN_PASSWORD is configured', async () => {
+    process.env.CODEMAN_PASSWORD = TEST_PASS;
+    const networkServer = new WebServer(0, false, true, '0.0.0.0');
+
+    await networkServer.start();
+    await networkServer.stop();
+
+    delete process.env.CODEMAN_PASSWORD;
+  });
+
+  it('allows non-loopback startup with the explicit unauthenticated-network override', async () => {
+    const networkServer = new WebServer(NETWORK_OVERRIDE_PORT, false, true, '0.0.0.0', undefined, true);
+
+    await networkServer.start();
+    const res = await fetch(`http://localhost:${NETWORK_OVERRIDE_PORT}/api/status`);
+    expect(res.status).toBe(200);
+    await networkServer.stop();
+  });
+
+  it('allows non-loopback startup with the explicit unauthenticated-network env override', async () => {
+    process.env.CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK = 'true';
+    const networkServer = new WebServer(0, false, true, '0.0.0.0');
+
+    await networkServer.start();
+    await networkServer.stop();
+
+    delete process.env.CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK;
+  });
 });
diff --git a/test/cli-commands.test.ts b/test/cli-commands.test.ts
index db903c41..ae65fb5d 100644
--- a/test/cli-commands.test.ts
+++ b/test/cli-commands.test.ts
@@ -5,6 +5,7 @@
  */
 
 import { describe, it, expect } from 'vitest';
+import { program } from '../src/cli.js';
 
 describe('CLI Command Parsing', () => {
   describe('Command Structure', () => {
@@ -72,11 +73,11 @@ describe('CLI Command Parsing', () => {
     ];
 
     const findCommand = (name: string): Command | undefined => {
-      return commands.find(c => c.name === name || c.aliases.includes(name));
+      return commands.find((c) => c.name === name || c.aliases.includes(name));
     };
 
     const findSubcommand = (parent: Command, name: string): Command | undefined => {
-      return parent.subcommands?.find(c => c.name === name || c.aliases.includes(name));
+      return parent.subcommands?.find((c) => c.name === name || c.aliases.includes(name));
     };
 
     it('should find commands by name', () => {
@@ -103,7 +104,7 @@ describe('CLI Command Parsing', () => {
     });
 
     it('should have descriptions for all commands', () => {
-      commands.forEach(cmd => {
+      commands.forEach((cmd) => {
         expect(cmd.description).toBeTruthy();
       });
     });
@@ -267,13 +268,13 @@ describe('CLI Command Parsing', () => {
     });
 
     it('should have defaults for web flags', () => {
-      webFlags.forEach(flag => {
+      webFlags.forEach((flag) => {
         expect(flag.default).toBeDefined();
       });
     });
 
     it('should have defaults for tui flags', () => {
-      tuiFlags.forEach(flag => {
+      tuiFlags.forEach((flag) => {
         expect(flag.default).toBeDefined();
       });
     });
@@ -322,7 +323,7 @@ describe('CLI Command Parsing', () => {
       help += `${description}\n`;
       if (options.length > 0) {
         help += '\nOptions:\n';
-        options.forEach(opt => {
+        options.forEach((opt) => {
           help += `  ${opt}\n`;
         });
       }
@@ -345,6 +346,15 @@ describe('CLI Command Parsing', () => {
       expect(help).toContain('--host');
     });
 
+    it('documents the unauthenticated network override in real web command help', () => {
+      const webCommand = program.commands.find((command) => command.name() === 'web');
+      expect(webCommand).toBeDefined();
+
+      const help = webCommand!.helpInformation();
+      expect(help).toContain('--allow-unauthenticated-network');
+      expect(help).toMatch(/without\s+CODEMAN_PASSWORD/);
+    });
+
     it('should format properly', () => {
       const help = generateHelp('test', 'Test command', ['--flag']);
       const lines = help.split('\n');
@@ -474,22 +484,27 @@ describe('CLI Output Formatting', () => {
     }
 
     const formatRow = (values: string[], columns: Column[]): string => {
-      return values.map((val, i) => {
-        const width = columns[i]?.width || 10;
-        return val.padEnd(width).substring(0, width);
-      }).join(' ');
+      return values
+        .map((val, i) => {
+          const width = columns[i]?.width || 10;
+          return val.padEnd(width).substring(0, width);
+        })
+        .join(' ');
     };
 
     const formatTable = (headers: string[], rows: string[][], widths: number[]): string => {
       const columns = headers.map((h, i) => ({ header: h, width: widths[i] }));
       const headerRow = formatRow(headers, columns);
-      const separator = columns.map(c => '-'.repeat(c.width)).join(' ');
-      const dataRows = rows.map(row => formatRow(row, columns));
+      const separator = columns.map((c) => '-'.repeat(c.width)).join(' ');
+      const dataRows = rows.map((row) => formatRow(row, columns));
       return [headerRow, separator, ...dataRows].join('\n');
     };
 
     it('should format single row', () => {
-      const columns = [{ header: 'ID', width: 10 }, { header: 'Status', width: 8 }];
+      const columns = [
+        { header: 'ID', width: 10 },
+        { header: 'Status', width: 8 },
+      ];
       const row = formatRow(['123', 'active'], columns);
       expect(row).toBe('123        active  ');
     });
@@ -503,7 +518,10 @@ describe('CLI Output Formatting', () => {
     it('should format complete table', () => {
       const table = formatTable(
         ['ID', 'Status'],
-        [['1', 'active'], ['2', 'idle']],
+        [
+          ['1', 'active'],
+          ['2', 'idle'],
+        ],
         [5, 8]
       );
       expect(table).toContain('ID');
@@ -587,7 +605,7 @@ describe('CLI Output Formatting', () => {
     });
 
     it('should format normal costs with 2 decimals', () => {
-      expect(formatCost(1.50)).toBe('$1.50');
+      expect(formatCost(1.5)).toBe('$1.50');
       expect(formatCost(0.05)).toBe('$0.05');
     });
 
@@ -633,7 +651,7 @@ describe('CLI Output Formatting', () => {
 
   describe('List Formatting', () => {
     const formatList = (items: string[], bullet: string = '-'): string => {
-      return items.map(item => `${bullet} ${item}`).join('\n');
+      return items.map((item) => `${bullet} ${item}`).join('\n');
     };
 
     const formatNumberedList = (items: string[]): string => {