diff --git a/bin/lib/onboard.js b/bin/lib/onboard.js
index cc853fc10e0..4f4edb49d8a 100644
--- a/bin/lib/onboard.js
+++ b/bin/lib/onboard.js
@@ -1775,6 +1775,9 @@ async function preflight() {
     console.log("  Cleaning up previous NemoClaw session...");
     runOpenshell(["forward", "stop", "18789"], { ignoreError: true });
     runOpenshell(["gateway", "destroy", "-g", GATEWAY_NAME], { ignoreError: true });
+    // Sandboxes under the destroyed gateway no longer exist in OpenShell —
+    // clear the local registry so `nemoclaw list` stays consistent. (#532)
+    registry.clearAll();
     console.log("  ✓ Previous session cleaned up");
   }
 
@@ -1901,6 +1904,8 @@ async function startGatewayWithOptions(_gpu, { exitOnFailure = true } = {}) {
 
   if (hasStaleGateway(gwInfo)) {
     runOpenshell(["gateway", "destroy", "-g", GATEWAY_NAME], { ignoreError: true });
+    // Sandboxes under the destroyed gateway no longer exist — clear registry. (#532)
+    registry.clearAll();
   }
 
   const gwArgs = ["--name", GATEWAY_NAME];
diff --git a/bin/lib/registry.js b/bin/lib/registry.js
index 885ea8c2ee6..de2cd0d9a77 100644
--- a/bin/lib/registry.js
+++ b/bin/lib/registry.js
@@ -120,6 +120,7 @@ function withLock(fn) {
   }
 }
 
+/** Load the sandbox registry from disk, returning an empty state if absent or corrupt. */
 function load() {
   try {
     if (fs.existsSync(REGISTRY_FILE)) {
@@ -150,11 +151,13 @@ function save(data) {
   }
 }
 
+/** Return the sandbox entry for the given name, or null if not found. */
 function getSandbox(name) {
   const data = load();
   return data.sandboxes[name] || null;
 }
 
+/** Return the name of the default sandbox, falling back to the first registered one. */
 function getDefault() {
   const data = load();
   if (data.defaultSandbox && data.sandboxes[data.defaultSandbox]) {
@@ -165,6 +168,7 @@ function getDefault() {
   return names.length > 0 ? names[0] : null;
 }
 
+/** Register a new sandbox in the registry, setting it as default if none exists. */
 function registerSandbox(entry) {
   return withLock(() => {
     const data = load();
@@ -184,6 +188,7 @@ function registerSandbox(entry) {
   });
 }
 
+/** Merge updates into an existing sandbox entry. Returns false if the sandbox does not exist. */
 function updateSandbox(name, updates) {
   return withLock(() => {
     const data = load();
@@ -197,6 +202,7 @@ function updateSandbox(name, updates) {
   });
 }
 
+/** Remove a sandbox by name and reassign the default if necessary. */
 function removeSandbox(name) {
   return withLock(() => {
     const data = load();
@@ -211,6 +217,7 @@ function removeSandbox(name) {
   });
 }
 
+/** List all registered sandboxes and the current default. */
 function listSandboxes() {
   const data = load();
   return {
@@ -219,6 +226,7 @@ function listSandboxes() {
   };
 }
 
+/** Set the named sandbox as the default. Returns false if the sandbox does not exist. */
 function setDefault(name) {
   return withLock(() => {
     const data = load();
@@ -229,7 +237,15 @@ function setDefault(name) {
   });
 }
 
+/** Reset the registry to an empty state, removing all sandboxes and the default selection. */
+function clearAll() {
+  withLock(() => {
+    save({ sandboxes: {}, defaultSandbox: null });
+  });
+}
+
 module.exports = {
+  clearAll,
   load,
   save,
   getSandbox,
diff --git a/test/registry.test.js b/test/registry.test.js
index 80fd0ddedc5..738677ae5b8 100644
--- a/test/registry.test.js
+++ b/test/registry.test.js
@@ -289,4 +289,29 @@ describe("advisory file locking", () => {
     const { sandboxes } = registry.listSandboxes();
     expect(sandboxes.length).toBe(20);
   });
+
+  it("clearAll removes all sandboxes and resets default", () => {
+    registry.registerSandbox({ name: "alpha" });
+    registry.registerSandbox({ name: "beta" });
+    registry.setDefault("beta");
+    registry.clearAll();
+    const { sandboxes, defaultSandbox } = registry.listSandboxes();
+    assert.equal(sandboxes.length, 0);
+    assert.equal(defaultSandbox, null);
+  });
+
+  it("clearAll persists empty state to disk", () => {
+    registry.registerSandbox({ name: "persist-me" });
+    registry.clearAll();
+    const data = JSON.parse(fs.readFileSync(regFile, "utf-8"));
+    assert.deepEqual(data.sandboxes, {});
+    assert.equal(data.defaultSandbox, null);
+  });
+
+  it("clearAll is safe to call on empty registry", () => {
+    registry.clearAll();
+    const { sandboxes, defaultSandbox } = registry.listSandboxes();
+    assert.equal(sandboxes.length, 0);
+    assert.equal(defaultSandbox, null);
+  });
 });