diff --git a/src/cli/claude.ts b/src/cli/claude.ts
index 48bc8a8fd0..a9e64fc1af 100644
--- a/src/cli/claude.ts
+++ b/src/cli/claude.ts
@@ -354,8 +354,17 @@ export function readConnectedClaudeContextWindows(path = DEFAULT_CATALOG_PATH):
   }
 }
 
-async function ensureProxyForClaude(): Promise<number | null> {
-  const live = await findLiveProxy();
+export type ClaudeProxyEnsureDeps = {
+  findLiveProxy?: typeof findLiveProxy;
+};
+
+export async function ensureProxyForClaude(deps: ClaudeProxyEnsureDeps = {}): Promise<number | null> {
+  // A proxy that has only just bound can miss a single probe while its event loop
+  // is still settling startup work — the same just-started race the stop paths
+  // already retry for (#764, SERVICE_STOP_LIVENESS). Only the attempts budget is
+  // borrowed here; the probe timeout remains DEFAULT_PROBE_TIMEOUT_MS (750 ms).
+  // Without this, `ocx claude` can spawn a second proxy while the first is serving.
+  const live = await (deps.findLiveProxy ?? findLiveProxy)({ attempts: 3 });
   if (live) return live.port;
   const cfgPort = loadConfig().port;
   const pinPort = typeof cfgPort === "number" && cfgPort > 0 ? cfgPort : 10100;
diff --git a/tests/claude-cli.test.ts b/tests/claude-cli.test.ts
index e33fb38035..8381b99e84 100644
--- a/tests/claude-cli.test.ts
+++ b/tests/claude-cli.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, test } from "bun:test";
-import { buildClaudeEnv, claudeNotFoundHint, rootSkipPermissionsNotice, shouldAllowRootSkipPermissions } from "../src/cli/claude";
+import { buildClaudeEnv, claudeNotFoundHint, ensureProxyForClaude, rootSkipPermissionsNotice, shouldAllowRootSkipPermissions } from "../src/cli/claude";
 import { commandInvocation } from "../src/lib/win-exec";
+import type { LivenessIo, LiveProxy } from "../src/server/proxy-liveness";
 import type { OcxConfig } from "../src/types";
 
 function cfg(extra?: Partial<OcxConfig>): OcxConfig {
@@ -25,6 +26,20 @@ const AUTH_PRESENT = {
   },
 };
 
+describe("ocx claude proxy liveness", () => {
+  test("retries the initial liveness probe before spawning a proxy", async () => {
+    const seen: (number | undefined)[] = [];
+    const findLiveProxy = async (io?: LivenessIo): Promise<LiveProxy> => {
+      seen.push(io?.attempts);
+      // retry semantics are covered by tests/proxy-liveness.test.ts:102-119; this pins that the launcher hands the stop-path budget down.
+      return { pid: 4242, port: 10100, source: "runtime" };
+    };
+
+    expect(await ensureProxyForClaude({ findLiveProxy })).toBe(10100);
+    expect(seen).toEqual([3]);
+  });
+});
+
 describe("ocx claude env assembly", () => {
   test("connected target injects only the hub base and client admission token", () => {
     const env = buildClaudeEnv(cfg(), {