diff --git a/apps/cli/package.json b/apps/cli/package.json
index 4edeb10..510caef 100644
--- a/apps/cli/package.json
+++ b/apps/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "claudemesh-cli",
-  "version": "1.9.5",
+  "version": "1.10.0",
   "description": "Peer mesh for Claude Code sessions — CLI + MCP server.",
   "keywords": [
     "claude-code",
diff --git a/apps/cli/src/commands/me.ts b/apps/cli/src/commands/me.ts
new file mode 100644
index 0000000..a8359fe
--- /dev/null
+++ b/apps/cli/src/commands/me.ts
@@ -0,0 +1,111 @@
+/**
+ * `claudemesh me` — cross-mesh workspace overview for the caller's user.
+ *
+ * Calls GET /v1/me/workspace which aggregates over every mesh the
+ * authenticated user belongs to: peer count, online count, topic count,
+ * unread @-mention count per mesh + global totals.
+ *
+ * Auth: mints a temporary read-scoped REST apikey on whichever mesh
+ * the user has joined first (any mesh works — the endpoint resolves
+ * to the issuing user, not the apikey's mesh).
+ *
+ * v0.4.0 substrate. Future verbs (`me topics`, `me notifications`,
+ * `me activity`, `me search`) layer on top of similar aggregating
+ * endpoints once they ship.
+ */
+
+import { withRestKey } from "~/services/api/with-rest-key.js";
+import { request } from "~/services/api/client.js";
+import { render } from "~/ui/render.js";
+import { bold, clay, cyan, dim, green, yellow } from "~/ui/styles.js";
+import { EXIT } from "~/constants/exit-codes.js";
+
+interface WorkspaceMesh {
+  meshId: string;
+  slug: string;
+  name: string;
+  memberId: string;
+  myRole: string;
+  joinedAt: string;
+  peers: number;
+  online: number;
+  topics: number;
+  unreadMentions: number;
+}
+
+interface WorkspaceResponse {
+  userId: string;
+  meshes: WorkspaceMesh[];
+  totals: {
+    meshes: number;
+    peers: number;
+    online: number;
+    topics: number;
+    unreadMentions: number;
+  };
+}
+
+export interface MeFlags {
+  mesh?: string;
+  json?: boolean;
+}
+
+export async function runMe(flags: MeFlags): Promise<number> {
+  return withRestKey(
+    {
+      meshSlug: flags.mesh ?? null,
+      purpose: "workspace-overview",
+      capabilities: ["read"],
+    },
+    async ({ secret }) => {
+      const ws = await request<WorkspaceResponse>({
+        path: "/api/v1/me/workspace",
+        token: secret,
+      });
+
+      if (flags.json) {
+        console.log(JSON.stringify(ws, null, 2));
+        return EXIT.SUCCESS;
+      }
+
+      render.section(
+        `${clay("workspace")} — ${bold(ws.userId.slice(0, 8))}  ${dim(
+          `· ${ws.totals.meshes} mesh${ws.totals.meshes === 1 ? "" : "es"}`,
+        )}`,
+      );
+
+      const totalsLine = [
+        `${green(String(ws.totals.online))}/${ws.totals.peers} online`,
+        `${ws.totals.topics} topic${ws.totals.topics === 1 ? "" : "s"}`,
+        ws.totals.unreadMentions > 0
+          ? yellow(`${ws.totals.unreadMentions} unread @you`)
+          : dim("0 unread @you"),
+      ].join(dim(" · "));
+      process.stdout.write("  " + totalsLine + "\n\n");
+
+      if (ws.meshes.length === 0) {
+        process.stdout.write(
+          dim("  no meshes joined — run `claudemesh new` or accept an invite\n"),
+        );
+        return EXIT.SUCCESS;
+      }
+
+      const slugWidth = Math.max(...ws.meshes.map((m) => m.slug.length), 8);
+      for (const m of ws.meshes) {
+        const slug = cyan(m.slug.padEnd(slugWidth));
+        const peers = `${m.online}/${m.peers}`;
+        const role = dim(m.myRole);
+        const unread =
+          m.unreadMentions > 0
+            ? "  " + yellow(`${m.unreadMentions} @you`)
+            : "";
+        process.stdout.write(
+          `  ${slug}  ${peers.padStart(5)} online  ${dim(
+            String(m.topics).padStart(2) + " topics",
+          )}  ${role}${unread}\n`,
+        );
+      }
+      return EXIT.SUCCESS;
+    },
+  );
+}
diff --git a/apps/cli/src/entrypoints/cli.ts b/apps/cli/src/entrypoints/cli.ts
index 02c63a3..d0eb1b0 100644
--- a/apps/cli/src/entrypoints/cli.ts
+++ b/apps/cli/src/entrypoints/cli.ts
@@ -123,6 +123,7 @@ Topic  (conversation scope, v0.2.0)
   claudemesh topic tail <topic>    live SSE tail [--limit --forward-only]
   claudemesh topic post <t> <msg>  encrypted REST post (v0.3.0 v2) [--reply-to <id>]
   claudemesh send "#topic" "msg"   send to a topic (WS path, v1 plaintext)
+  claudemesh me                    cross-mesh workspace overview (v0.4.0)
   claudemesh member list           mesh roster with online state [--online]
   claudemesh notification list     recent @-mentions of you [--since <ISO>]
 
@@ -672,6 +673,25 @@ async function main(): Promise<void> {
       break;
     }
 
+    // me — cross-mesh workspace overview (v0.4.0)
+    case "me": {
+      const sub = positionals[0];
+      const f = {
+        mesh: flags.mesh as string,
+        json: !!flags.json,
+      };
+      if (!sub || sub === "workspace" || sub === "overview") {
+        const { runMe } = await import("~/commands/me.js");
+        process.exit(await runMe(f));
+      } else {
+        console.error(
+          "Usage: claudemesh me  (cross-mesh overview; future: me topics, me notifications, me activity)",
+        );
+        process.exit(EXIT.INVALID_ARGS);
+      }
+      break;
+    }
+
     // member — mesh roster with online state (v1.7.0)
     case "member": case "members": {
       const sub = positionals[0] ?? "list";