diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6df90ff3236..029b12d29b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- ACP/sessions_spawn: honor explicit `model` overrides for ACP child sessions instead of silently falling back to the target agent default model. (#70210) Thanks @felix-miao.
 - CLI/Claude: hash only static extra system prompt parts when deciding whether to reuse a CLI session, so per-message inbound metadata no longer resets Claude CLI conversations on every turn. (#70122) Thanks @zijunl.
 - Hooks/Slack: standardize shared message hook routing fields (`threadId` / `replyToId`) and stop Slack outbound delivery from re-running `message_sending` inside the channel adapter, so plugins like thread-ownership make one outbound routing decision per reply. Thanks @vincentkoc.
 - Auto-reply/media: share one run-scoped reply media context between streamed block delivery and final payload filtering, so a local `MEDIA:` attachment is staged once and duplicate media sends are suppressed reliably. (#68111) Thanks @ayeshakhalid192007-dev.
diff --git a/src/acp/control-plane/manager.core.ts b/src/acp/control-plane/manager.core.ts
index f0692a78c2a..83346f145a8 100644
--- a/src/acp/control-plane/manager.core.ts
+++ b/src/acp/control-plane/manager.core.ts
@@ -311,7 +311,10 @@ export class AcpSessionManager {
     return await this.withSessionActor(sessionKey, async () => {
       const backend = this.deps.requireRuntimeBackend(input.backendId || input.cfg.acp?.backend);
       const runtime = backend.runtime;
-      const initialRuntimeOptions = validateRuntimeOptionPatch({ cwd: input.cwd });
+      const initialRuntimeOptions = validateRuntimeOptionPatch({
+        ...input.runtimeOptions,
+        ...(input.cwd !== undefined ? { cwd: input.cwd } : {}),
+      });
       const requestedCwd = initialRuntimeOptions.cwd;
       this.enforceConcurrentSessionLimit({
         cfg: input.cfg,
diff --git a/src/acp/control-plane/manager.test.ts b/src/acp/control-plane/manager.test.ts
index 02be0aa2da5..f78c6e6cd9c 100644
--- a/src/acp/control-plane/manager.test.ts
+++ b/src/acp/control-plane/manager.test.ts
@@ -1298,6 +1298,77 @@ describe("AcpSessionManager", () => {
     expect(runtimeState.ensureSession).toHaveBeenCalledTimes(1);
   });
 
+  it("persists runtime options provided during initializeSession", async () => {
+    const runtimeState = createRuntime();
+    hoisted.requireAcpRuntimeBackendMock.mockReturnValue({
+      id: "acpx",
+      runtime: runtimeState.runtime,
+    });
+    hoisted.upsertAcpSessionMetaMock.mockResolvedValue({
+      sessionKey: "agent:codex:acp:session-a",
+      storeSessionKey: "agent:codex:acp:session-a",
+      acp: readySessionMeta({
+        runtimeOptions: {
+          model: "openai-codex/gpt-5.4",
+        },
+      }),
+    });
+
+    const manager = new AcpSessionManager();
+    await manager.initializeSession({
+      cfg: baseCfg,
+      sessionKey: "agent:codex:acp:session-a",
+      agent: "codex",
+      mode: "persistent",
+      runtimeOptions: {
+        model: "openai-codex/gpt-5.4",
+      },
+    });
+
+    expect(extractRuntimeOptionsFromUpserts()).toContainEqual({
+      model: "openai-codex/gpt-5.4",
+    });
+  });
+
+  it("preserves runtimeOptions cwd when initializeSession cwd is omitted", async () => {
+    const runtimeState = createRuntime();
+    hoisted.requireAcpRuntimeBackendMock.mockReturnValue({
+      id: "acpx",
+      runtime: runtimeState.runtime,
+    });
+    hoisted.upsertAcpSessionMetaMock.mockResolvedValue({
+      sessionKey: "agent:codex:acp:session-cwd-runtime-options",
+      storeSessionKey: "agent:codex:acp:session-cwd-runtime-options",
+      acp: readySessionMeta({
+        runtimeOptions: {
+          cwd: "/workspace/from-runtime-options",
+        },
+        cwd: "/workspace/from-runtime-options",
+      }),
+    });
+
+    const manager = new AcpSessionManager();
+    await manager.initializeSession({
+      cfg: baseCfg,
+      sessionKey: "agent:codex:acp:session-cwd-runtime-options",
+      agent: "codex",
+      mode: "persistent",
+      runtimeOptions: {
+        cwd: "/workspace/from-runtime-options",
+      },
+    });
+
+    expect(runtimeState.ensureSession).toHaveBeenCalledWith(
+      expect.objectContaining({
+        sessionKey: "agent:codex:acp:session-cwd-runtime-options",
+        cwd: "/workspace/from-runtime-options",
+      }),
+    );
+    expect(extractRuntimeOptionsFromUpserts()).toContainEqual({
+      cwd: "/workspace/from-runtime-options",
+    });
+  });
+
   it("drops cached runtime handles after tolerated close failures", async () => {
     const closeFailures = [
       {
diff --git a/src/acp/control-plane/manager.types.ts b/src/acp/control-plane/manager.types.ts
index f1a5550a2db..f8357d24854 100644
--- a/src/acp/control-plane/manager.types.ts
+++ b/src/acp/control-plane/manager.types.ts
@@ -44,6 +44,7 @@ export type AcpInitializeSessionInput = {
   agent: string;
   mode: AcpRuntimeSessionMode;
   resumeSessionId?: string;
+  runtimeOptions?: Partial<AcpSessionRuntimeOptions>;
   cwd?: string;
   backendId?: string;
 };
diff --git a/src/agents/acp-spawn.test.ts b/src/agents/acp-spawn.test.ts
index 0694b3a7f4a..86def2e3375 100644
--- a/src/agents/acp-spawn.test.ts
+++ b/src/agents/acp-spawn.test.ts
@@ -718,6 +718,30 @@ describe("spawnAcpDirect", () => {
     expect(transcriptCalls[1]?.threadId).toBe("child-thread");
   });
 
+  it("passes model override into ACP session initialization", async () => {
+    const result = await spawnAcpDirect(
+      {
+        task: "Investigate flaky tests",
+        agentId: "codex",
+        model: "openai-codex/gpt-5.4",
+      },
+      {
+        agentSessionKey: "agent:main:main",
+      },
+    );
+
+    expectAcceptedSpawn(result);
+    expect(hoisted.initializeSessionMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        sessionKey: expect.stringMatching(/^agent:codex:acp:/),
+        agent: "codex",
+        runtimeOptions: {
+          model: "openai-codex/gpt-5.4",
+        },
+      }),
+    );
+  });
+
   it("inherits subagent envelope fields onto ACP children", async () => {
     replaceSpawnConfig({
       ...hoisted.state.cfg,
diff --git a/src/agents/acp-spawn.ts b/src/agents/acp-spawn.ts
index 150baacd425..7204362066d 100644
--- a/src/agents/acp-spawn.ts
+++ b/src/agents/acp-spawn.ts
@@ -104,6 +104,7 @@ export type SpawnAcpParams = {
   label?: string;
   agentId?: string;
   resumeSessionId?: string;
+  model?: string;
   cwd?: string;
   mode?: SpawnAcpMode;
   thread?: boolean;
@@ -890,6 +891,7 @@ async function initializeAcpSpawnRuntime(params: {
   targetAgentId: string;
   runtimeMode: AcpRuntimeSessionMode;
   resumeSessionId?: string;
+  model?: string;
   cwd?: string;
 }): Promise<AcpSpawnInitializedRuntime> {
   const storePath = resolveStorePath(params.cfg.session?.store, { agentId: params.targetAgentId });
@@ -914,6 +916,7 @@ async function initializeAcpSpawnRuntime(params: {
     agent: params.targetAgentId,
     mode: params.runtimeMode,
     resumeSessionId: params.resumeSessionId,
+    runtimeOptions: params.model ? { model: params.model } : undefined,
     cwd: params.cwd,
     backendId: params.cfg.acp?.backend,
   });
@@ -1249,6 +1252,7 @@ export async function spawnAcpDirect(
       targetAgentId,
       runtimeMode,
       resumeSessionId: params.resumeSessionId,
+      model: params.model,
       cwd: runtimeCwd,
     });
     initializedRuntime = initializedSession.runtimeCloseHandle;
diff --git a/src/agents/tools/sessions-spawn-tool.test.ts b/src/agents/tools/sessions-spawn-tool.test.ts
index 900d1c4bca5..d3c59bc68b1 100644
--- a/src/agents/tools/sessions-spawn-tool.test.ts
+++ b/src/agents/tools/sessions-spawn-tool.test.ts
@@ -247,6 +247,28 @@ describe("sessions_spawn tool", () => {
     expect(hoisted.registerSubagentRunMock).not.toHaveBeenCalled();
   });
 
+  it("forwards model override to ACP runtime spawns", async () => {
+    const tool = createSessionsSpawnTool({
+      agentSessionKey: "agent:main:main",
+    });
+
+    await tool.execute("call-2-model", {
+      runtime: "acp",
+      task: "investigate the failing CI run",
+      agentId: "codex",
+      model: "github-copilot/claude-sonnet-4.6",
+    });
+
+    expect(hoisted.spawnAcpDirectMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        task: "investigate the failing CI run",
+        agentId: "codex",
+        model: "github-copilot/claude-sonnet-4.6",
+      }),
+      expect.any(Object),
+    );
+  });
+
   it("adds requested role to forwarded ACP failures", async () => {
     hoisted.spawnAcpDirectMock.mockResolvedValueOnce({
       status: "forbidden",
diff --git a/src/agents/tools/sessions-spawn-tool.ts b/src/agents/tools/sessions-spawn-tool.ts
index a9e64fc20e2..ccfa198b9ab 100644
--- a/src/agents/tools/sessions-spawn-tool.ts
+++ b/src/agents/tools/sessions-spawn-tool.ts
@@ -245,6 +245,7 @@ export function createSessionsSpawnTool(
             label: label || undefined,
             agentId: requestedAgentId,
             resumeSessionId,
+            model: modelOverride,
             cwd,
             mode: mode === "run" || mode === "session" ? mode : undefined,
             thread,