diff --git a/src/agents/harness/selection.test.ts b/src/agents/harness/selection.test.ts
index a2b7abb38c71..1108c27c1ccb 100644
--- a/src/agents/harness/selection.test.ts
+++ b/src/agents/harness/selection.test.ts
@@ -1503,6 +1503,35 @@ describe("selectAgentHarness", () => {
     },
   );
 
+  it("keeps native model run controls compatible with Codex", () => {
+    expect(
+      buildAgentHarnessSupportContext({
+        provider: "openai",
+        modelId: "gpt-5.6-sol",
+        modelProvider: {
+          api: "openai-responses",
+          baseUrl: "https://api.openai.com/v1",
+          requestTransportOverrides: "none",
+        },
+        requestedRuntime: "codex",
+        config: {
+          agents: {
+            defaults: {
+              models: {
+                "openai/gpt-5.6-sol": {
+                  params: { thinking: "xhigh", fastMode: true, fastAutoOnSeconds: 30 },
+                },
+              },
+            },
+          },
+        } as OpenClawConfig,
+      }).modelProvider,
+    ).toMatchObject({
+      requestTransportOverrides: "none",
+      runtimePolicy: { compatibleIds: ["openclaw", "codex"] },
+    });
+  });
+
   it("rejects explicit Codex when agent request params cannot be reproduced", () => {
     const supports = vi.fn((ctx: Parameters<AgentHarness["supports"]>[0]) =>
       ctx.modelProvider?.requestTransportOverrides === "present"
diff --git a/src/agents/model-extra-params.ts b/src/agents/model-extra-params.ts
index ab1ce192c9d5..20cf6e060348 100644
--- a/src/agents/model-extra-params.ts
+++ b/src/agents/model-extra-params.ts
@@ -1,3 +1,5 @@
+import { normalizeFastMode } from "@openclaw/normalization-core/string-coerce";
+import { normalizeThinkLevel } from "../auto-reply/thinking.shared.js";
 import type { OpenClawConfig } from "../config/types.openclaw.js";
 import { modelKey } from "../shared/model-key.js";
 import { resolveAgentConfig } from "./agent-scope-config.js";
@@ -8,6 +10,35 @@ type ModelExtraParamSources = {
   agentParams?: Record<string, unknown>;
 };
 
+const FAST_MODE_CUTOFF_MODEL_PARAM_KEYS = new Set([
+  "fastAutoOnSeconds",
+  "fastSeconds",
+  "fast_auto_on_seconds",
+  "fast_seconds",
+]);
+
+// Native harnesses receive recognized values as typed run controls. Other value
+// shapes with the same keys remain authored provider request parameters.
+function isAgentRuntimeModelParam(key: string, value: unknown): boolean {
+  if (key === "thinking") {
+    return (
+      value === false ||
+      value === "disabled" ||
+      value === "none" ||
+      (typeof value === "string" && normalizeThinkLevel(value) !== undefined)
+    );
+  }
+  if (key === "fastMode" || key === "fast_mode") {
+    return normalizeFastMode(value) !== undefined;
+  }
+  return (
+    FAST_MODE_CUTOFF_MODEL_PARAM_KEYS.has(key) &&
+    typeof value === "number" &&
+    Number.isInteger(value) &&
+    value > 0
+  );
+}
+
 function legacyModelKey(provider: string, modelId: string): string | undefined {
   const rawKey = `${provider.trim()}/${modelId.trim()}`;
   const canonicalKey = modelKey(provider, modelId);
@@ -36,12 +67,19 @@ export function resolveModelExtraParamSources(params: {
   return { defaultParams, modelParams, agentParams };
 }
 
-/** Returns whether embedded OpenClaw would apply authored request parameters. */
+/** Returns whether embedded OpenClaw would apply authored provider request parameters. */
 export function hasModelExtraParams(
   params: Parameters<typeof resolveModelExtraParamSources>[0],
 ): boolean {
   const sources = resolveModelExtraParamSources(params);
-  return [sources.defaultParams, sources.modelParams, sources.agentParams].some(
-    (source) => source !== undefined && Object.keys(source).length > 0,
+  if (
+    [sources.defaultParams, sources.agentParams].some(
+      (source) => source !== undefined && Object.keys(source).length > 0,
+    )
+  ) {
+    return true;
+  }
+  return Object.entries(sources.modelParams ?? {}).some(
+    ([key, value]) => !isAgentRuntimeModelParam(key, value),
   );
 }
diff --git a/src/agents/openai-routing.test.ts b/src/agents/openai-routing.test.ts
index eb4e44ae78bf..b3c4c69d914a 100644
--- a/src/agents/openai-routing.test.ts
+++ b/src/agents/openai-routing.test.ts
@@ -36,6 +36,62 @@ describe("OpenAI runtime routing policy", () => {
     ).toBe(true);
   });
 
+  it.each([
+    ["thinking", { thinking: "xhigh" }],
+    ["fastMode", { fastMode: true }],
+    ["fast_mode", { fast_mode: true }],
+    ["fastAutoOnSeconds", { fastMode: "auto", fastAutoOnSeconds: 30 }],
+    ["fast_auto_on_seconds", { fastMode: "auto", fast_auto_on_seconds: 30 }],
+    ["fastSeconds", { fastMode: "auto", fastSeconds: 30 }],
+    ["fast_seconds", { fastMode: "auto", fast_seconds: 30 }],
+  ])("keeps Codex for model-scoped %s controls", (_label, params) => {
+    const config = {
+      agents: {
+        defaults: {
+          models: {
+            "openai/gpt-5.6-sol": {
+              params,
+            },
+          },
+        },
+      },
+    } as OpenClawConfig;
+
+    expect(
+      resolveOpenAIImplicitAgentRuntime({
+        provider: "openai",
+        modelId: "gpt-5.6-sol",
+        config,
+        env: {},
+      }),
+    ).toBe("codex");
+  });
+
+  it.each([
+    ["provider-native thinking", { thinking: { type: "enabled", budget_tokens: 2_048 } }],
+    ["invalid fast mode", { fastMode: { enabled: true } }],
+    ["invalid fast cutoff", { fastAutoOnSeconds: "30" }],
+  ])("keeps %s values on the OpenClaw runtime", (_label, params) => {
+    const config = {
+      agents: {
+        defaults: {
+          models: {
+            "openai/gpt-5.6-sol": { params },
+          },
+        },
+      },
+    } as OpenClawConfig;
+
+    expect(
+      resolveOpenAIImplicitAgentRuntime({
+        provider: "openai",
+        modelId: "gpt-5.6-sol",
+        config,
+        env: {},
+      }),
+    ).toBe("openclaw");
+  });
+
   it("maps provider route facts onto a closed implicit runtime", () => {
     expect(
       resolveOpenAIImplicitAgentRuntime({ provider: "openai", modelId: "gpt-5.6", env: {} }),