diff --git a/packages/core/src/__tests__/session-manager.test.ts b/packages/core/src/__tests__/session-manager.test.ts
index 48dca8269..ed0649830 100644
--- a/packages/core/src/__tests__/session-manager.test.ts
+++ b/packages/core/src/__tests__/session-manager.test.ts
@@ -2545,6 +2545,62 @@ describe("spawnOrchestrator", () => {
     expect(existsSync(listLogPath)).toBe(false);
   });
 
+  it("destroys orphaned runtime when reuse strategy finds alive runtime but get returns null", async () => {
+    const opencodeAgent: Agent = {
+      ...mockAgent,
+      name: "opencode",
+    };
+    const registryWithOpenCode: PluginRegistry = {
+      ...mockRegistry,
+      get: vi.fn().mockImplementation((slot: string) => {
+        if (slot === "runtime") return mockRuntime;
+        if (slot === "agent") return opencodeAgent;
+        if (slot === "workspace") return mockWorkspace;
+        return null;
+      }),
+    };
+
+    const configWithReuse: OrchestratorConfig = {
+      ...config,
+      defaults: { ...config.defaults, agent: "opencode" },
+      projects: {
+        ...config.projects,
+        "my-app": {
+          ...config.projects["my-app"],
+          agent: "opencode",
+          orchestratorSessionStrategy: "reuse",
+        },
+      },
+    };
+
+    const orphanedHandle = makeHandle("rt-orphaned");
+    writeMetadata(sessionsDir, "app-orchestrator", {
+      worktree: join(tmpDir, "my-app"),
+      branch: "main",
+      status: "working",
+      role: "orchestrator",
+      project: "my-app",
+      agent: "opencode",
+      runtimeHandle: JSON.stringify(orphanedHandle),
+      createdAt: new Date().toISOString(),
+    });
+
+    vi.mocked(mockRuntime.isAlive).mockImplementation(async (handle: RuntimeHandle) => {
+      if (handle?.id === "rt-orphaned") {
+        deleteMetadata(sessionsDir, "app-orchestrator");
+        return true;
+      }
+      return false;
+    });
+
+    const sm = createSessionManager({ config: configWithReuse, registry: registryWithOpenCode });
+    const session = await sm.spawnOrchestrator({ projectId: "my-app" });
+
+    expect(session.id).toBe("app-orchestrator");
+    expect(mockRuntime.destroy).toHaveBeenCalledWith(orphanedHandle);
+    expect(mockRuntime.create).toHaveBeenCalled();
+  });
+
   it("reuses mapped OpenCode session id when strategy is reuse and runtime is restarted", async () => {
     const opencodeAgent: Agent = {
       ...mockAgent,
@@ -2846,6 +2902,27 @@ describe("spawnOrchestrator", () => {
     expect(meta?.["orchestratorSessionReused"]).toBeUndefined();
   });
 
+  it("respawns the orchestrator when stale metadata exists but the runtime is dead", async () => {
+    writeMetadata(sessionsDir, "app-orchestrator", {
+      worktree: join(tmpDir, "my-app"),
+      branch: "main",
+      status: "working",
+      project: "my-app",
+      role: "orchestrator",
+      runtimeHandle: JSON.stringify(makeHandle("rt-stale")),
+      createdAt: new Date().toISOString(),
+    });
+
+    vi.mocked(mockRuntime.isAlive).mockResolvedValueOnce(false);
+
+    const sm = createSessionManager({ config, registry: mockRegistry });
+    await sm.spawnOrchestrator({ projectId: "my-app" });
+
+    expect(mockRuntime.create).toHaveBeenCalledTimes(1);
+    const meta = readMetadataRaw(sessionsDir, "app-orchestrator");
+    expect(meta?.["runtimeHandle"]).toBe(JSON.stringify(makeHandle("rt-1")));
+  });
+
   it("uses orchestratorModel when configured", async () => {
     const configWithOrchestratorModel: OrchestratorConfig = {
       ...config,
diff --git a/packages/core/src/session-manager.ts b/packages/core/src/session-manager.ts
index 6a959545f..dfb3b855c 100644
--- a/packages/core/src/session-manager.ts
+++ b/packages/core/src/session-manager.ts
@@ -1008,18 +1008,38 @@ export function createSessionManager(deps: SessionManagerDeps): OpenCodeSessionM
       writeFileSync(systemPromptFile, orchestratorConfig.systemPrompt, "utf-8");
     }
 
-    const existingOrchestrator = await get(sessionId);
-    if (existingOrchestrator?.runtimeHandle) {
-      const existingAlive = await plugins.runtime
-        .isAlive(existingOrchestrator.runtimeHandle)
-        .catch(() => false);
+    const existingOrchestratorMetadata = readMetadataRaw(sessionsDir, sessionId);
+    const existingRuntimeHandle = existingOrchestratorMetadata?.["runtimeHandle"]
+      ? safeJsonParse<RuntimeHandle>(existingOrchestratorMetadata["runtimeHandle"])
+      : null;
+    if (existingRuntimeHandle) {
+      const existingAlive = await plugins.runtime.isAlive(existingRuntimeHandle).catch(() => false);
       if (existingAlive && orchestratorSessionStrategy === "reuse") {
-        existingOrchestrator.metadata["orchestratorSessionReused"] = "true";
-        return existingOrchestrator;
+        const existingOrchestrator = await get(sessionId);
+        if (existingOrchestrator) {
+          existingOrchestrator.metadata["orchestratorSessionReused"] = "true";
+          return existingOrchestrator;
+        }
+        await plugins.runtime.destroy(existingRuntimeHandle).catch(() => undefined);
+      } else if (existingAlive) {
+        await plugins.runtime.destroy(existingRuntimeHandle).catch(() => undefined);
       }
-      if (existingAlive && orchestratorSessionStrategy !== "reuse") {
-        await plugins.runtime.destroy(existingOrchestrator.runtimeHandle).catch(() => undefined);
+    }
+
+    if (!existingOrchestratorMetadata && !reserveSessionId(sessionsDir, sessionId)) {
+      const raceSession = await get(sessionId);
+      if (raceSession?.runtimeHandle) {
+        const raceAlive = await plugins.runtime
+          .isAlive(raceSession.runtimeHandle)
+          .catch(() => false);
+        if (raceAlive && orchestratorSessionStrategy === "reuse") {
+          raceSession.metadata["orchestratorSessionReused"] = "true";
+          return raceSession;
+        }
       }
+      throw new Error(
+        `Failed to reserve orchestrator session ID ${sessionId} (concurrent spawn detected)`,
+      );
     }
 
     const reusableOpenCodeSessionId =
diff --git a/packages/integration-tests/src/agent-opencode.integration.test.ts b/packages/integration-tests/src/agent-opencode.integration.test.ts
index 11d6ef56a..ce2e46d87 100644
--- a/packages/integration-tests/src/agent-opencode.integration.test.ts
+++ b/packages/integration-tests/src/agent-opencode.integration.test.ts
@@ -202,10 +202,10 @@ describe("getLaunchCommand (integration)", () => {
       prompt: "fix the bug",
     });
     expect(cmd).toContain("--agent 'sisyphus'");
-    expect(cmd).toContain("opencode run --title 'AO:test-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1'");
     expect(cmd).toContain("'fix the bug'");
     expect(cmd).not.toContain("--prompt");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("--agent 'sisyphus'");
   });
 
@@ -215,7 +215,7 @@ describe("getLaunchCommand (integration)", () => {
       systemPrompt: "You are an orchestrator",
       prompt: "do the task",
     });
-    expect(cmd).toContain("opencode run --title 'AO:test-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1'");
     expect(cmd).not.toContain("--prompt");
     expect(cmd).toContain("You are an orchestrator");
     expect(cmd).toContain("do the task");
@@ -227,7 +227,7 @@ describe("getLaunchCommand (integration)", () => {
       systemPromptFile: "/tmp/orchestrator-prompt.md",
       prompt: "do the task",
     });
-    expect(cmd).toContain("opencode run --title 'AO:test-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1'");
     expect(cmd).not.toContain("--prompt");
     expect(cmd).toContain(
       "$(cat '/tmp/orchestrator-prompt.md'; printf '\\n\\n'; printf %s 'do the task')",
@@ -252,7 +252,7 @@ describe("getLaunchCommand (integration)", () => {
       prompt: "review this code",
     });
     expect(cmd).toContain("--agent 'oracle'");
-    expect(cmd).toContain("opencode run --title 'AO:test-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1'");
     expect(cmd).not.toContain("--prompt");
     expect(cmd).toContain("You are an expert");
     expect(cmd).toContain("review this code");
@@ -277,9 +277,9 @@ describe("getLaunchCommand (integration)", () => {
       systemPromptFile: "/tmp/orchestrator-prompt.md",
     });
     expect(cmd).toContain(
-      "opencode run --title 'AO:test-orchestrator' \"$(cat '/tmp/orchestrator-prompt.md')\"",
+      "opencode run --format json --title 'AO:test-orchestrator' \"$(cat '/tmp/orchestrator-prompt.md')\"",
     );
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("escapes single quotes in systemPrompt", () => {
@@ -303,7 +303,7 @@ describe("getLaunchCommand (integration)", () => {
       ...baseConfig,
       prompt: "fix  and `backtick` and 'quote'",
     });
-    expect(cmd).toContain("opencode run --title 'AO:test-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1'");
     expect(cmd).toContain("fix  and `backtick`");
     expect(cmd).not.toContain("--prompt");
   });
@@ -313,8 +313,8 @@ describe("getLaunchCommand (integration)", () => {
       ...baseConfig,
       prompt: "",
     });
-    expect(cmd).toContain("opencode run --title 'AO:test-1' --command true");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1' --command true");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("opencode session list --format json");
     expect(cmd).toContain("AO:test-1");
   });
@@ -324,7 +324,7 @@ describe("getLaunchCommand (integration)", () => {
       ...baseConfig,
       prompt: "line1\nline2",
     });
-    expect(cmd).toContain("opencode run --title 'AO:test-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1'");
     expect(cmd).toContain("'line1");
     expect(cmd).not.toContain("--prompt");
   });
@@ -336,8 +336,8 @@ describe("getLaunchCommand (integration)", () => {
     });
     expect(cmd).toContain("--title 'AO:test-1'");
     expect(cmd).not.toContain("--prompt 'start work'");
-    expect(cmd).toContain("opencode run --title 'AO:test-1' 'start work'");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:test-1' 'start work'");
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("uses --session when existing OpenCode session id is provided", () => {
diff --git a/packages/plugins/agent-opencode/src/index.test.ts b/packages/plugins/agent-opencode/src/index.test.ts
index 9a6d2dead..15cbfe04e 100644
--- a/packages/plugins/agent-opencode/src/index.test.ts
+++ b/packages/plugins/agent-opencode/src/index.test.ts
@@ -112,17 +112,17 @@ describe("getLaunchCommand", () => {
 
   it("generates base command without prompt", () => {
     const cmd = agent.getLaunchCommand(makeLaunchConfig());
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' --command true");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1' --command true");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("opencode session list --format json");
     expect(cmd).toContain("AO:sess-1");
-    expect(cmd).toContain("try { rows = JSON.parse(input); } catch { process.exit(1); }");
+    expect(cmd).toContain("try{rows=JSON.parse(input)}catch{process.exit(1)}");
   });
 
   it("uses --prompt with shell-escaped prompt", () => {
     const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "Fix it" }));
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' 'Fix it'");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1' 'Fix it'");
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("includes --model with shell-escaped value", () => {
@@ -135,16 +135,16 @@ describe("getLaunchCommand", () => {
       makeLaunchConfig({ prompt: "Go", model: "claude-sonnet-4-5-20250929" }),
     );
     expect(cmd).toContain(
-      "opencode run --title 'AO:sess-1' --model 'claude-sonnet-4-5-20250929' 'Go'",
+      "opencode run --format json --title 'AO:sess-1' --model 'claude-sonnet-4-5-20250929' 'Go'",
     );
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("--model 'claude-sonnet-4-5-20250929'");
   });
 
   it("escapes single quotes in prompt (POSIX shell escaping)", () => {
     const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "it's broken" }));
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' 'it'\\''s broken'");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1' 'it'\\''s broken'");
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("omits optional flags when not provided", () => {
@@ -165,8 +165,10 @@ describe("getLaunchCommand", () => {
     const cmd = agent.getLaunchCommand(
       makeLaunchConfig({ subagent: "sisyphus", prompt: "fix bug" }),
     );
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' --agent 'sisyphus' 'fix bug'");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain(
+      "opencode run --format json --title 'AO:sess-1' --agent 'sisyphus' 'fix bug'",
+    );
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("--agent 'sisyphus'");
   });
 
@@ -179,9 +181,9 @@ describe("getLaunchCommand", () => {
       }),
     );
     expect(cmd).toContain(
-      "opencode run --title 'AO:sess-1' --agent 'sisyphus' --model 'claude-sonnet-4-5-20250929' 'fix the bug'",
+      "opencode run --format json --title 'AO:sess-1' --agent 'sisyphus' --model 'claude-sonnet-4-5-20250929' 'fix the bug'",
     );
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("--agent 'sisyphus'");
     expect(cmd).toContain("--model 'claude-sonnet-4-5-20250929'");
   });
@@ -205,8 +207,8 @@ describe("getLaunchCommand", () => {
   it("backward compatible: no agent flag when subagent not provided", () => {
     const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "fix it" }));
     expect(cmd).not.toContain("--agent");
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' 'fix it'");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1' 'fix it'");
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("combines model and prompt without agent (backward compatible)", () => {
@@ -215,9 +217,9 @@ describe("getLaunchCommand", () => {
     );
     expect(cmd).not.toContain("--agent");
     expect(cmd).toContain(
-      "opencode run --title 'AO:sess-1' --model 'claude-sonnet-4-5-20250929' 'Go'",
+      "opencode run --format json --title 'AO:sess-1' --model 'claude-sonnet-4-5-20250929' 'Go'",
     );
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("--model 'claude-sonnet-4-5-20250929'");
   });
 
@@ -228,7 +230,7 @@ describe("getLaunchCommand", () => {
     const cmd = agent.getLaunchCommand(
       makeLaunchConfig({ systemPrompt: "You are an orchestrator" }),
     );
-    expect(cmd).toContain("opencode run --title 'AO:sess-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1'");
     expect(cmd).toContain("'You are an orchestrator'");
   });
 
@@ -236,7 +238,7 @@ describe("getLaunchCommand", () => {
     const cmd = agent.getLaunchCommand(
       makeLaunchConfig({ systemPrompt: "You are an orchestrator", prompt: "do the task" }),
     );
-    expect(cmd).toContain("opencode run --title 'AO:sess-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1'");
     expect(cmd).not.toContain("--prompt 'You are an orchestrator");
     expect(cmd).toContain("do the task'");
   });
@@ -249,22 +251,26 @@ describe("getLaunchCommand", () => {
   it("handles very long systemPrompt", () => {
     const longPrompt = "A".repeat(500);
     const cmd = agent.getLaunchCommand(makeLaunchConfig({ systemPrompt: longPrompt }));
-    expect(cmd).toContain("opencode run --title 'AO:sess-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1'");
     expect(cmd.length).toBeGreaterThan(500);
   });
 
   it("generates command with systemPromptFile via shell substitution", () => {
     const cmd = agent.getLaunchCommand(makeLaunchConfig({ systemPromptFile: "/tmp/prompt.md" }));
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' \"$(cat '/tmp/prompt.md')\"");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain(
+      "opencode run --format json --title 'AO:sess-1' \"$(cat '/tmp/prompt.md')\"",
+    );
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("escapes path in systemPromptFile", () => {
     const cmd = agent.getLaunchCommand(
       makeLaunchConfig({ systemPromptFile: "/tmp/it's-prompt.md" }),
     );
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' \"$(cat '/tmp/it'\\''s-prompt.md')\"");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain(
+      "opencode run --format json --title 'AO:sess-1' \"$(cat '/tmp/it'\\''s-prompt.md')\"",
+    );
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("systemPromptFile takes precedence over systemPrompt", () => {
@@ -287,9 +293,9 @@ describe("getLaunchCommand", () => {
       }),
     );
     expect(cmd).toContain(
-      "opencode run --title 'AO:my-orchestrator' \"$(cat '/tmp/orchestrator.md')\"",
+      "opencode run --format json --title 'AO:my-orchestrator' \"$(cat '/tmp/orchestrator.md')\"",
     );
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("exec opencode --session");
   });
 
   it("combines systemPromptFile with subagent and prompt", () => {
@@ -301,8 +307,8 @@ describe("getLaunchCommand", () => {
       }),
     );
     expect(cmd).toContain("--agent 'sisyphus'");
-    expect(cmd).toContain("opencode run --title 'AO:sess-1'");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1'");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("--agent 'sisyphus'");
     expect(cmd).not.toContain("--prompt");
     expect(cmd).toContain(
@@ -322,7 +328,7 @@ describe("getLaunchCommand", () => {
 
   it("handles prompt with newlines", () => {
     const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "line1\nline2\nline3" }));
-    expect(cmd).toContain("opencode run --title 'AO:sess-1'");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1'");
     expect(cmd).toContain("'line1");
   });
 
@@ -353,12 +359,36 @@ describe("getLaunchCommand", () => {
 
   it("handles empty prompt", () => {
     const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "" }));
-    expect(cmd).toContain("opencode run --title 'AO:sess-1' --command true");
-    expect(cmd).toContain("&& exec opencode --session");
+    expect(cmd).toContain("opencode run --format json --title 'AO:sess-1' --command true");
+    expect(cmd).toContain("exec opencode --session");
     expect(cmd).toContain("opencode session list --format json");
     expect(cmd).toContain("AO:sess-1");
   });
 
+  it("validates session ID format in fallback script", () => {
+    const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "test" }));
+    expect(cmd).toContain("isValidId=id=>/^ses_[A-Za-z0-9_-]+$/.test(id)");
+    expect(cmd).toContain("isValidId(r.id)");
+  });
+
+  it("primary capture validates session ID type and format", () => {
+    const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "test" }));
+    expect(cmd).toContain("isValidId=id=>typeof id===");
+    expect(cmd).toContain("isValidId(evt.session_id)");
+  });
+
+  it("fallback sort handles invalid date strings without NaN", () => {
+    const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "test" }));
+    expect(cmd).toContain("timestamp=v=>");
+    expect(cmd).toContain("Number.NEGATIVE_INFINITY");
+  });
+
+  it("pipes JSON output into node instead of treating the session id as a command", () => {
+    const cmd = agent.getLaunchCommand(makeLaunchConfig({ prompt: "Fix it" }));
+    expect(cmd).toContain("| node -e");
+    expect(cmd).not.toContain('| "$(node -e');
+  });
+
   it("uses existing session id", () => {
     const cmd = agent.getLaunchCommand(
       makeLaunchConfig({
diff --git a/packages/plugins/agent-opencode/src/index.ts b/packages/plugins/agent-opencode/src/index.ts
index 3e047778b..4d80dac34 100644
--- a/packages/plugins/agent-opencode/src/index.ts
+++ b/packages/plugins/agent-opencode/src/index.ts
@@ -37,48 +37,6 @@ function parseSessionList(raw: string): OpenCodeSessionListEntry[] {
   });
 }
 
-function buildSessionLookupScript(): string {
-  const script = `
-let input = '';
-process.stdin.on('data', c => input += c).on('end', () => {
-  const title = process.argv[1];
-  let rows;
-  try { rows = JSON.parse(input); } catch { process.exit(1); }
-  if (!Array.isArray(rows)) process.exit(1);
-  const isValidId = id => /^ses_[A-Za-z0-9_-]+$/.test(id);
-  const timestamp = value => {
-    if (typeof value === 'number' && Number.isFinite(value)) return value;
-    if (typeof value === 'string') {
-      const parsed = Date.parse(value);
-      return Number.isNaN(parsed) ? Number.NEGATIVE_INFINITY : parsed;
-    }
-    return Number.NEGATIVE_INFINITY;
-  };
-  const matches = rows
-    .filter(r => r && r.title === title && typeof r.id === 'string' && isValidId(r.id))
-    .sort((a, b) => {
-      const ta = timestamp(a.updated);
-      const tb = timestamp(b.updated);
-      if (ta === tb) return 0;
-      return tb - ta;
-    });
-  if (matches.length === 0) process.exit(1);
-  process.stdout.write(matches[0].id);
-});
-  `.trim();
-  return script.replace(/\n/g, " ").replace(/\s+/g, " ");
-}
-
-function buildContinueSessionCommand(sessionTitle: string, sharedOptions: string[]): string {
-  const script = buildSessionLookupScript();
-  const options = sharedOptions.length > 0 ? ` ${sharedOptions.join(" ")}` : "";
-  return [
-    `SES_ID=$(opencode session list --format json | node -e ${shellEscape(script)} ${shellEscape(sessionTitle)})`,
-    '[ -n "$SES_ID" ]',
-    `exec opencode --session "$SES_ID"${options}`,
-  ].join(" && ");
-}
-
 // =============================================================================
 // Plugin Manifest
 // =============================================================================
@@ -138,13 +96,25 @@ function createOpenCodeAgent(): Agent {
       if (!existingSessionId) {
         const runOptions = ["--title", shellEscape(`AO:${config.sessionId}`), ...sharedOptions];
         const runCommand = promptValue
-          ? ["opencode", "run", ...runOptions, promptValue].join(" ")
-          : ["opencode", "run", ...runOptions, "--command", "true"].join(" ");
-        const continueCommand = buildContinueSessionCommand(
-          `AO:${config.sessionId}`,
-          sharedOptions,
+          ? ["opencode", "run", "--format", "json", ...runOptions, promptValue].join(" ")
+          : ["opencode", "run", "--format", "json", ...runOptions, "--command", "true"].join(" ");
+
+        const captureSessionId = [
+          "node",
+          "-e",
+          shellEscape(
+            "let buf='';process.stdin.on('data',c=>buf+=c).on('end',()=>{const lines=buf.toString().split('\\n');const isValidId=id=>typeof id==='string'&&/^ses_[A-Za-z0-9_-]+$/.test(id);for(const line of lines){if(!line.trim())continue;try{const evt=JSON.parse(line);if(evt.type==='step_start'&&isValidId(evt.session_id)){process.stdout.write(evt.session_id);process.exit(0);}}catch{}}process.exit(1);})",
+          ),
+        ].join(" ");
+
+        const fallbackSessionId = `opencode session list --format json | node -e ${shellEscape("let input='';process.stdin.on('data',c=>input+=c).on('end',()=>{const title=process.argv[1];let rows;try{rows=JSON.parse(input)}catch{process.exit(1)};if(!Array.isArray(rows))process.exit(1);const isValidId=id=>/^ses_[A-Za-z0-9_-]+$/.test(id);const timestamp=v=>{if(typeof v==='number'&&Number.isFinite(v))return v;if(typeof v==='string'){const p=Date.parse(v);return Number.isNaN(p)?Number.NEGATIVE_INFINITY:p;}return Number.NEGATIVE_INFINITY;};const matches=rows.filter(r=>r&&r.title===title&&typeof r.id==='string'&&isValidId(r.id)).sort((a,b)=>timestamp(b.updated)-timestamp(a.updated));if(matches.length===0)process.exit(1);process.stdout.write(matches[0].id);});")} ${shellEscape(`AO:${config.sessionId}`)}`;
+
+        const sessionIdCapture = `"$( { ${runCommand} | ${captureSessionId}; } || ${fallbackSessionId} )"`;
+
+        const continueCommand = ["opencode", "--session", sessionIdCapture, ...sharedOptions].join(
+          " ",
         );
-        return `${runCommand} && ${continueCommand}`;
+        return `exec ${continueCommand}`;
       }
 
       if (promptValue) {