diff --git a/agent-orchestrator.yaml.example b/agent-orchestrator.yaml.example
index 99daf79e6..58339691d 100644
--- a/agent-orchestrator.yaml.example
+++ b/agent-orchestrator.yaml.example
@@ -8,7 +8,7 @@ dataDir: ~/.agent-orchestrator
 worktreeDir: ~/.worktrees
 
 # Web dashboard port
-port: 3000
+port: 4100
 
 # Terminal server ports (defaults: 14800/14801 — chosen to avoid conflicts with dev tools)
 # Override when running multiple dashboards to avoid EADDRINUSE
diff --git a/packages/cli/__tests__/commands/init.test.ts b/packages/cli/__tests__/commands/init.test.ts
index 7f530fd38..42a6b033d 100644
--- a/packages/cli/__tests__/commands/init.test.ts
+++ b/packages/cli/__tests__/commands/init.test.ts
@@ -37,7 +37,7 @@ describe("init command", () => {
     expect(existsSync(outputPath)).toBe(true);
   });
 
-  it("auto mode uses port 3000 when it is available", async () => {
+  it("auto mode uses port 4100 when it is available", async () => {
     tmpDir = mkdtempSync(join(tmpdir(), "ao-init-test-"));
     const outputPath = join(tmpDir, "agent-orchestrator.yaml");
 
@@ -50,17 +50,17 @@ describe("init command", () => {
     await program.parseAsync(["node", "test", "init", "--auto", "--output", outputPath]);
 
     const content = readFileSync(outputPath, "utf-8");
-    expect(content).toContain("port: 3000");
+    expect(content).toContain("port: 4100");
   });
 
-  it("auto mode picks next free port when 3000 is occupied", async () => {
+  it("auto mode picks next free port when 4100 is occupied", async () => {
     tmpDir = mkdtempSync(join(tmpdir(), "ao-init-test-"));
     const outputPath = join(tmpDir, "agent-orchestrator.yaml");
 
-    // Occupy port 3000
+    // Occupy port 4100
     const blocker = createServer();
     await new Promise<void>((resolve) => {
-      blocker.listen(3000, "127.0.0.1", () => resolve());
+      blocker.listen(4100, "127.0.0.1", () => resolve());
     });
 
     try {
@@ -73,14 +73,14 @@ describe("init command", () => {
       await program.parseAsync(["node", "test", "init", "--auto", "--output", outputPath]);
 
       const content = readFileSync(outputPath, "utf-8");
-      // Should NOT be 3000 since we're occupying it
-      expect(content).not.toContain("port: 3000");
-      // Should pick 3001 (or higher if 3001 is also taken)
+      // Should NOT be 4100 since we're occupying it
+      expect(content).not.toContain("port: 4100");
+      // Should pick 4101 (or higher if 4101 is also taken)
       const portMatch = content.match(/port: (\d+)/);
       expect(portMatch).toBeTruthy();
       const port = parseInt(portMatch![1], 10);
-      expect(port).toBeGreaterThan(3000);
-      expect(port).toBeLessThan(3100);
+      expect(port).toBeGreaterThan(4100);
+      expect(port).toBeLessThan(4200);
     } finally {
       await new Promise<void>((resolve) => blocker.close(() => resolve()));
     }
diff --git a/packages/cli/__tests__/commands/open.test.ts b/packages/cli/__tests__/commands/open.test.ts
index e05481233..719c2a98d 100644
--- a/packages/cli/__tests__/commands/open.test.ts
+++ b/packages/cli/__tests__/commands/open.test.ts
@@ -34,7 +34,7 @@ beforeEach(() => {
   mockConfigRef.current = {
     dataDir: "/tmp/ao",
     worktreeDir: "/tmp/wt",
-    port: 3000,
+    port: 4100,
     defaults: {
       runtime: "tmux",
       agent: "claude-code",
diff --git a/packages/cli/__tests__/commands/review-check.test.ts b/packages/cli/__tests__/commands/review-check.test.ts
index 13a5843b5..e63b92392 100644
--- a/packages/cli/__tests__/commands/review-check.test.ts
+++ b/packages/cli/__tests__/commands/review-check.test.ts
@@ -113,7 +113,7 @@ beforeEach(() => {
 
   mockConfigRef.current = {
     configPath,
-    port: 3000,
+    port: 4100,
     defaults: {
       runtime: "tmux",
       agent: "claude-code",
diff --git a/packages/cli/__tests__/commands/session.test.ts b/packages/cli/__tests__/commands/session.test.ts
index ba44da863..aa6620675 100644
--- a/packages/cli/__tests__/commands/session.test.ts
+++ b/packages/cli/__tests__/commands/session.test.ts
@@ -124,7 +124,7 @@ beforeEach(() => {
 
   mockConfigRef.current = {
     configPath,
-    port: 3000,
+    port: 4100,
     defaults: {
       runtime: "tmux",
       agent: "claude-code",
diff --git a/packages/cli/__tests__/commands/spawn.test.ts b/packages/cli/__tests__/commands/spawn.test.ts
index 594f2de86..bbe09d353 100644
--- a/packages/cli/__tests__/commands/spawn.test.ts
+++ b/packages/cli/__tests__/commands/spawn.test.ts
@@ -72,7 +72,7 @@ beforeEach(() => {
 
   mockConfigRef.current = {
     configPath,
-    port: 3000,
+    port: 4100,
     defaults: {
       runtime: "tmux",
       agent: "claude-code",
diff --git a/packages/cli/__tests__/commands/status.test.ts b/packages/cli/__tests__/commands/status.test.ts
index e3e77eb37..c91853fc1 100644
--- a/packages/cli/__tests__/commands/status.test.ts
+++ b/packages/cli/__tests__/commands/status.test.ts
@@ -170,7 +170,7 @@ beforeEach(() => {
 
   mockConfigRef.current = {
     configPath,
-    port: 3000,
+    port: 4100,
     readyThresholdMs: 300_000,
     defaults: {
       runtime: "tmux",
diff --git a/packages/cli/__tests__/lib/plugins.test.ts b/packages/cli/__tests__/lib/plugins.test.ts
index 04defd512..a2d717999 100644
--- a/packages/cli/__tests__/lib/plugins.test.ts
+++ b/packages/cli/__tests__/lib/plugins.test.ts
@@ -9,7 +9,7 @@ function makeConfig(
   return {
     dataDir: "/tmp",
     worktreeDir: "/tmp/wt",
-    port: 3000,
+    port: 4100,
     defaults: { runtime: "tmux", agent: defaultAgent, workspace: "worktree", notifiers: [] },
     projects: Object.fromEntries(
       Object.entries(projects ?? { app: {} }).map(([id, p]) => [
diff --git a/packages/cli/__tests__/lib/session-utils.test.ts b/packages/cli/__tests__/lib/session-utils.test.ts
index 4a3f2ac39..f6f967d2e 100644
--- a/packages/cli/__tests__/lib/session-utils.test.ts
+++ b/packages/cli/__tests__/lib/session-utils.test.ts
@@ -60,7 +60,7 @@ describe("findProjectForSession", () => {
     ({
       dataDir: "/tmp",
       worktreeDir: "/tmp/wt",
-      port: 3000,
+      port: 4100,
       defaults: { runtime: "tmux", agent: "claude-code", workspace: "worktree", notifiers: [] },
       projects: Object.fromEntries(
         Object.entries(projects).map(([id, p]) => [
diff --git a/packages/cli/src/commands/init.ts b/packages/cli/src/commands/init.ts
index 17c54e256..8f43ab5f3 100644
--- a/packages/cli/src/commands/init.ts
+++ b/packages/cli/src/commands/init.ts
@@ -13,7 +13,7 @@ import {
   formatProjectTypeForDisplay,
 } from "../lib/project-detection.js";
 
-const DEFAULT_PORT = 3000;
+const DEFAULT_PORT = 4100;
 const MAX_PORT_SCAN = 100;
 
 /** Find the first available port starting from `start`, scanning upward. */
diff --git a/packages/core/src/__tests__/lifecycle-manager.test.ts b/packages/core/src/__tests__/lifecycle-manager.test.ts
index eb6a9efd1..17a09d80a 100644
--- a/packages/core/src/__tests__/lifecycle-manager.test.ts
+++ b/packages/core/src/__tests__/lifecycle-manager.test.ts
@@ -114,7 +114,7 @@ beforeEach(() => {
 
   config = {
     configPath,
-    port: 3000,
+    port: 4100,
     defaults: {
       runtime: "mock",
       agent: "mock-agent",
diff --git a/packages/core/src/__tests__/plugin-integration.test.ts b/packages/core/src/__tests__/plugin-integration.test.ts
index 209883fc2..42edf0896 100644
--- a/packages/core/src/__tests__/plugin-integration.test.ts
+++ b/packages/core/src/__tests__/plugin-integration.test.ts
@@ -160,7 +160,7 @@ beforeEach(() => {
 
   config = {
     configPath,
-    port: 3000,
+    port: 4100,
     defaults: {
       runtime: "mock",
       agent: "mock-agent",
diff --git a/packages/core/src/__tests__/session-manager.test.ts b/packages/core/src/__tests__/session-manager.test.ts
index 96d56edff..3c6b85efa 100644
--- a/packages/core/src/__tests__/session-manager.test.ts
+++ b/packages/core/src/__tests__/session-manager.test.ts
@@ -87,7 +87,7 @@ beforeEach(() => {
 
   config = {
     configPath,
-    port: 3000,
+    port: 4100,
     defaults: {
       runtime: "mock",
       agent: "mock-agent",
diff --git a/packages/core/src/config.ts b/packages/core/src/config.ts
index 4a4c34070..cf1cc13b1 100644
--- a/packages/core/src/config.ts
+++ b/packages/core/src/config.ts
@@ -89,7 +89,7 @@ const DefaultPluginsSchema = z.object({
 });
 
 const OrchestratorConfigSchema = z.object({
-  port: z.number().default(3000),
+  port: z.number().default(4100),
   terminalPort: z.number().optional(),
   directTerminalPort: z.number().optional(),
   readyThresholdMs: z.number().nonnegative().default(300_000),
diff --git a/packages/integration-tests/src/cli-spawn-core-read-new.integration.test.ts b/packages/integration-tests/src/cli-spawn-core-read-new.integration.test.ts
index 6c1b3f791..4bc778c2a 100644
--- a/packages/integration-tests/src/cli-spawn-core-read-new.integration.test.ts
+++ b/packages/integration-tests/src/cli-spawn-core-read-new.integration.test.ts
@@ -59,7 +59,7 @@ describe.skipIf(!tmuxOk)("CLI-Core integration (hash-based architecture)", () =>
 
     // Create config WITHOUT dataDir/worktreeDir (new architecture)
     const config = {
-      port: 3000,
+      port: 4100,
       defaults: {
         runtime: "tmux",
         agent: "claude-code",
@@ -155,7 +155,7 @@ describe.skipIf(!tmuxOk)("CLI-Core integration (hash-based architecture)", () =>
     // Create session-manager with configPath
     const config: OrchestratorConfig = {
       configPath, // This enables hash-based architecture
-      port: 3000,
+      port: 4100,
       readyThresholdMs: 300_000,
       defaults: {
         runtime: "tmux",
@@ -215,7 +215,7 @@ describe.skipIf(!tmuxOk)("CLI-Core integration (hash-based architecture)", () =>
 
     const config: OrchestratorConfig = {
       configPath,
-      port: 3000,
+      port: 4100,
       readyThresholdMs: 300_000,
       defaults: {
         runtime: "tmux",
diff --git a/packages/integration-tests/src/config-metadata-service.integration.test.ts b/packages/integration-tests/src/config-metadata-service.integration.test.ts
index bff3cee0c..6db37bac6 100644
--- a/packages/integration-tests/src/config-metadata-service.integration.test.ts
+++ b/packages/integration-tests/src/config-metadata-service.integration.test.ts
@@ -36,7 +36,7 @@ describe("config → metadata service integration (real filesystem)", () => {
 
     // Create a minimal config file
     const config = {
-      port: 3000,
+      port: 4100,
       defaults: {
         runtime: "tmux",
         agent: "claude-code",
diff --git a/packages/integration-tests/src/terminal-web.integration.test.ts b/packages/integration-tests/src/terminal-web.integration.test.ts
index db1914846..90adecc11 100644
--- a/packages/integration-tests/src/terminal-web.integration.test.ts
+++ b/packages/integration-tests/src/terminal-web.integration.test.ts
@@ -56,13 +56,13 @@ describe("terminal-web integration", () => {
   });
 
   describe("URL construction", () => {
-    it("default dashboard URL uses port 3000", async () => {
+    it("default dashboard URL uses port 4100", async () => {
       const logSpy = vi.spyOn(console, "log").mockImplementation(() => {});
       const terminal = webPlugin.create();
       await terminal.openSession(makeSession({ id: "url-test" }));
 
       expect(logSpy).toHaveBeenCalledWith(
-        expect.stringContaining("http://localhost:3000/sessions/url-test/terminal"),
+        expect.stringContaining("http://localhost:4100/sessions/url-test/terminal"),
       );
     });
 
diff --git a/packages/plugins/terminal-web/src/index.test.ts b/packages/plugins/terminal-web/src/index.test.ts
index 4a4843368..49ba85f08 100644
--- a/packages/plugins/terminal-web/src/index.test.ts
+++ b/packages/plugins/terminal-web/src/index.test.ts
@@ -72,7 +72,7 @@ describe("terminal-web", () => {
       const terminal = create();
       await terminal.openSession(makeSession());
 
-      expect(logSpy).toHaveBeenCalledWith(expect.stringContaining("http://localhost:3000"));
+      expect(logSpy).toHaveBeenCalledWith(expect.stringContaining("http://localhost:4100"));
     });
 
     it("uses custom dashboard URL", async () => {
diff --git a/packages/plugins/terminal-web/src/index.ts b/packages/plugins/terminal-web/src/index.ts
index 9cbf808c4..ff1c96e84 100644
--- a/packages/plugins/terminal-web/src/index.ts
+++ b/packages/plugins/terminal-web/src/index.ts
@@ -16,7 +16,7 @@ export const manifest = {
  * that the dashboard needs.
  */
 export function create(config?: Record<string, unknown>): Terminal {
-  const dashboardUrl = (config?.dashboardUrl as string) ?? "http://localhost:3000";
+  const dashboardUrl = (config?.dashboardUrl as string) ?? "http://localhost:4100";
 
   // Track which sessions have been "opened" (URL generated for the dashboard)
   const openSessions = new Set<string>();
diff --git a/packages/web/src/__tests__/api-routes.test.ts b/packages/web/src/__tests__/api-routes.test.ts
index 9bae0f315..aab936a4a 100644
--- a/packages/web/src/__tests__/api-routes.test.ts
+++ b/packages/web/src/__tests__/api-routes.test.ts
@@ -127,7 +127,7 @@ const mockRegistry: PluginRegistry = {
 
 const mockConfig: OrchestratorConfig = {
   configPath: "/tmp/ao-test/agent-orchestrator.yaml",
-  port: 3000,
+  port: 4100,
   readyThresholdMs: 300_000,
   defaults: { runtime: "tmux", agent: "claude-code", workspace: "worktree", notifiers: [] },
   projects: {
@@ -166,7 +166,7 @@ import { GET as eventsGET } from "@/app/api/events/route";
 
 function makeRequest(url: string, init?: RequestInit): NextRequest {
   return new NextRequest(
-    new URL(url, "http://localhost:3000"),
+    new URL(url, "http://localhost:4100"),
     init as ConstructorParameters<typeof NextRequest>[1],
   );
 }