diff --git a/extensions/codex/harness.test.ts b/extensions/codex/harness.test.ts
index c387732d9ebf..ef24f197506b 100644
--- a/extensions/codex/harness.test.ts
+++ b/extensions/codex/harness.test.ts
@@ -262,6 +262,17 @@ describe("Codex agent harness supports()", () => {
     ).toEqual({ supported: true, priority: 100 });
   });
 
+  it("lets explicit Codex model discovery run before auth has been prepared", () => {
+    expect(
+      harness.supports({
+        provider: "openai",
+        modelId: "gpt-future",
+        requestedRuntime: "codex",
+        modelProvider: { requestTransportOverrides: "none" },
+      }),
+    ).toEqual({ supported: true, priority: 100 });
+  });
+
   it.each([
     {
       label: "automatic runtime selection",
diff --git a/extensions/codex/harness.ts b/extensions/codex/harness.ts
index 8fdb1698da98..942e6ab55077 100644
--- a/extensions/codex/harness.ts
+++ b/extensions/codex/harness.ts
@@ -210,9 +210,9 @@ export function createCodexAppServerAgentHarness(
         provider === "openai" &&
         ctx.requestedRuntime === "codex" &&
         Boolean(ctx.modelId?.trim()) &&
-        preparedAuth?.source === "harness" &&
-        preparedAuth.mode === undefined &&
-        preparedAuth.requirement === undefined &&
+        (preparedAuth === undefined || preparedAuth.source === "harness") &&
+        preparedAuth?.mode === undefined &&
+        preparedAuth?.requirement === undefined &&
         ctx.modelProvider?.api === undefined &&
         ctx.modelProvider?.baseUrl === undefined &&
         ctx.modelProvider?.azureApiVersion === undefined &&
diff --git a/extensions/openai/openai-chatgpt-provider.ts b/extensions/openai/openai-chatgpt-provider.ts
index abc8cffb168d..148e69e43617 100644
--- a/extensions/openai/openai-chatgpt-provider.ts
+++ b/extensions/openai/openai-chatgpt-provider.ts
@@ -327,6 +327,25 @@ function resolveCodexForwardCompatModel(ctx: ProviderResolveDynamicModelContext)
       maxTokens: OPENAI_CODEX_GPT_54_MAX_TOKENS,
       cost: OPENAI_CODEX_GPT_54_MINI_COST,
     };
+  } else if (
+    ctx.agentRuntimeId === "codex" &&
+    ctx.authProfileId === undefined &&
+    ctx.authProfileMode === undefined &&
+    ctx.providerConfig?.auth === undefined
+  ) {
+    // Codex owns its account-scoped model catalog. When that catalog is not yet
+    // available, keep the requested identity intact and let the native runtime
+    // decide whether the account can actually use it.
+    templateIds = OPENAI_CODEX_GPT_56_MODEL_IDS;
+    patch = {
+      reasoning: true,
+      input: ["text", "image"],
+      thinkingLevelMap: OPENAI_CODEX_GPT_56_THINKING_LEVEL_MAP,
+      compat: {
+        supportsReasoningEffort: true,
+        supportedReasoningEfforts: ["low", "medium", "high", "xhigh", "max"],
+      },
+    };
   } else {
     return undefined;
   }
@@ -365,6 +384,8 @@ function resolveCodexForwardCompatModel(ctx: ProviderResolveDynamicModelContext)
       contextWindow: patch?.contextWindow ?? DEFAULT_CONTEXT_TOKENS,
       contextTokens: patch?.contextTokens,
       maxTokens: patch?.maxTokens ?? DEFAULT_CONTEXT_TOKENS,
+      ...(patch?.thinkingLevelMap ? { thinkingLevelMap: patch.thinkingLevelMap } : {}),
+      ...(patch?.compat ? { compat: patch.compat } : {}),
     } as ProviderRuntimeModel)
   );
 }
diff --git a/extensions/openai/openai-provider.test.ts b/extensions/openai/openai-provider.test.ts
index 828469f6a9a3..ffafd1088f8a 100644
--- a/extensions/openai/openai-provider.test.ts
+++ b/extensions/openai/openai-provider.test.ts
@@ -1766,6 +1766,74 @@ describe("buildOpenAIProvider", () => {
     ).toEqual({ effort: "high", transport: "sse" });
   });
 
+  it("delegates an unlisted first-party model to its explicitly selected Codex runtime", () => {
+    const provider = buildOpenAIProvider();
+    const model = provider.resolveDynamicModel?.({
+      provider: "openai",
+      modelId: "gpt-future",
+      modelRegistry: { find: () => null },
+      agentRuntimeId: "codex",
+    } as never);
+
+    expect(model).toMatchObject({
+      provider: "openai",
+      id: "gpt-future",
+      api: "openai-chatgpt-responses",
+      baseUrl: "https://chatgpt.com/backend-api/codex",
+      compat: { supportedReasoningEfforts: ["low", "medium", "high", "xhigh", "max"] },
+    });
+    expect(
+      provider
+        .resolveThinkingProfile?.({
+          provider: "openai",
+          modelId: "gpt-future",
+          agentRuntime: "codex",
+          api: model?.api,
+          compat: model?.compat,
+        } as never)
+        ?.levels.map((level) => level.id),
+    ).toContain("max");
+    expect(
+      provider
+        .resolveThinkingProfile?.({
+          provider: "openai",
+          modelId: "gpt-future",
+          agentRuntime: "codex",
+        } as never)
+        ?.levels.map((level) => level.id),
+    ).toEqual(expect.arrayContaining(["xhigh", "max"]));
+  });
+
+  it("does not invent an unlisted model for authored Platform credentials", () => {
+    const provider = buildOpenAIProvider();
+
+    expect(
+      provider.resolveDynamicModel?.({
+        provider: "openai",
+        modelId: "gpt-future",
+        modelRegistry: { find: () => null },
+        agentRuntimeId: "codex",
+        authProfileId: "openai:platform",
+        authProfileMode: "api_key",
+        providerConfig: {
+          auth: "api-key",
+          api: "openai-responses",
+          baseUrl: "https://api.openai.com/v1",
+        },
+      } as never),
+    ).toBeUndefined();
+    expect(
+      provider
+        .resolveThinkingProfile?.({
+          provider: "openai",
+          modelId: "gpt-future",
+          agentRuntime: "codex",
+          api: "openai-responses",
+        } as never)
+        ?.levels.map((level) => level.id),
+    ).not.toContain("max");
+  });
+
   it("restores gpt-5.3-codex-spark only through ChatGPT/Codex OAuth routing", () => {
     const provider = buildOpenAIProvider();
 
diff --git a/extensions/openai/thinking-policy.ts b/extensions/openai/thinking-policy.ts
index 648ef4feccaf..a354e5565e01 100644
--- a/extensions/openai/thinking-policy.ts
+++ b/extensions/openai/thinking-policy.ts
@@ -110,6 +110,12 @@ function buildOpenAIThinkingProfile(params: {
     (agentRuntime === "openclaw" ||
       agentRuntime === "auto" ||
       (agentRuntime === "codex" && codexSupportsUltra));
+  const nativeCodexNeedsAccountEffortValidation =
+    agentRuntime === "codex" &&
+    params.compat?.supportedReasoningEfforts === undefined &&
+    (params.api === undefined || params.api === "openai-chatgpt-responses") &&
+    !matchesExactOrPrefix(params.modelId, params.xhighModelIds) &&
+    !modelId.startsWith("gpt-5.6");
   const defaultLevel = isGpt56Variant ? "medium" : undefined;
   const fallbackLevels: ProviderThinkingProfile["levels"] = [
     ...OPENAI_THINKING_BASE_LEVELS,
@@ -118,6 +124,9 @@ function buildOpenAIThinkingProfile(params: {
       : []),
     ...(supportsMax ? [{ id: "max" as const }] : []),
     ...(supportsUltra ? [{ id: "ultra" as const }] : []),
+    ...(nativeCodexNeedsAccountEffortValidation
+      ? [{ id: "xhigh" as const }, { id: "max" as const }]
+      : []),
   ];
   const levels =
     agentRuntime === "codex" && resolvedCodexEfforts !== undefined
diff --git a/src/agents/model-auth-availability.test.ts b/src/agents/model-auth-availability.test.ts
index cd0eac62a4f6..3b25baadfb5d 100644
--- a/src/agents/model-auth-availability.test.ts
+++ b/src/agents/model-auth-availability.test.ts
@@ -875,6 +875,15 @@ describe("createModelAuthAvailabilityResolver", () => {
     expect(result).not.toHaveProperty("selectedRoute");
   });
 
+  it("keeps one unconfigured Codex route indeterminate until native account validation", () => {
+    expect(
+      evaluate({
+        resolution: { ...dualRoutes, routes: [subscriptionRoute] },
+        syntheticAuthProviderRefs: ["codex"],
+      }),
+    ).toMatchObject({ availability: undefined, evidence: "synthetic" });
+  });
+
   it("does not let invalid automatic profile evidence block synthetic Codex ownership", () => {
     expect(
       evaluate({
diff --git a/src/agents/model-auth-availability.ts b/src/agents/model-auth-availability.ts
index daed53540aaf..5c01163c002d 100644
--- a/src/agents/model-auth-availability.ts
+++ b/src/agents/model-auth-availability.ts
@@ -1106,6 +1106,10 @@ export function createModelAuthAvailabilityResolver(
       sourcePlan,
       configuredAuthMode: automaticRouteAuthMode,
       ...(syntheticCodexOwnsAuth ? { runtimeAuthOwner: { id: "codex" } } : {}),
+      ...(syntheticCodexOwnsAuth &&
+      resolveMergedModelProviderConfig(params.cfg, provider) === undefined
+        ? { allowNativeAuthOnSingleRoute: true }
+        : {}),
     });
     if (routeAuthDecision.kind === "deferred" && syntheticCodexOwnsAuth) {
       return { availability: undefined, routeResolution, evidence: "synthetic" };
diff --git a/src/agents/openai-model-routes.ts b/src/agents/openai-model-routes.ts
index 25ded9d10f6e..3be387b24f71 100644
--- a/src/agents/openai-model-routes.ts
+++ b/src/agents/openai-model-routes.ts
@@ -59,6 +59,7 @@ export function selectOpenAIModelRouteAuth(params: {
   sourcePlan: ProviderModelAuthSourcePlan;
   configuredAuthMode?: string;
   runtimeAuthOwner?: { id: string };
+  allowNativeAuthOnSingleRoute?: boolean;
 }) {
   return selectProviderModelRouteAuth({ provider: OPENAI_PROVIDER_ID, ...params });
 }
diff --git a/src/agents/provider-model-route-auth.test.ts b/src/agents/provider-model-route-auth.test.ts
index 90163e10d3c7..ef62b48eadfe 100644
--- a/src/agents/provider-model-route-auth.test.ts
+++ b/src/agents/provider-model-route-auth.test.ts
@@ -336,6 +336,36 @@ describe("provider model route auth", () => {
     });
   });
 
+  it("lets an explicit native owner authenticate its sole compatible route", () => {
+    expect(
+      selectProviderModelRouteAuth({
+        provider: "openai",
+        resolution: { ...routes, routes: [routes.routes[1]] },
+        runtimeAuthOwner: { id: "codex" },
+        allowNativeAuthOnSingleRoute: true,
+        sourcePlan: buildProviderModelAuthSourcePlan({ profiles: [] }),
+      }),
+    ).toEqual({
+      kind: "deferred",
+      reason: "runtime-auth-owner",
+      routeSupport: {
+        requestTransportOverrides: "none",
+        runtimePolicy: { compatibleIds: ["openclaw", "codex"] },
+      },
+    });
+  });
+
+  it("does not infer native ownership for an explicitly authored single route", () => {
+    expect(
+      selectProviderModelRouteAuth({
+        provider: "openai",
+        resolution: { ...routes, routes: [routes.routes[1]] },
+        runtimeAuthOwner: { id: "codex" },
+        sourcePlan: buildProviderModelAuthSourcePlan({ profiles: [] }),
+      }),
+    ).toMatchObject({ kind: "rejected", reason: "configured-auth" });
+  });
+
   it.each([
     ["Platform", routes.routes[0], profile("openai:chatgpt", "oauth", "ready")],
     ["subscription", routes.routes[1], profile("openai:platform", "api_key", "ready")],
diff --git a/src/agents/provider-model-route-auth.ts b/src/agents/provider-model-route-auth.ts
index 4125479207e0..e9441074e656 100644
--- a/src/agents/provider-model-route-auth.ts
+++ b/src/agents/provider-model-route-auth.ts
@@ -285,6 +285,8 @@ export function selectProviderModelRouteAuth(params: {
   configuredAuthMode?: string;
   /** Explicit native auth owner allowed to defer an otherwise unowned route. */
   runtimeAuthOwner?: { id: string };
+  /** True only when no provider transport or credentials were authored. */
+  allowNativeAuthOnSingleRoute?: boolean;
 }): ProviderModelRouteAuthDecision {
   const requiredProfile =
     params.sourcePlan.kind === "required" && params.sourcePlan.source.kind === "profile"
@@ -412,7 +414,16 @@ export function selectProviderModelRouteAuth(params: {
     const runtimeAuthOwnerIsCompatible =
       Boolean(normalizedRuntimeAuthOwner) &&
       routeSupport.runtimePolicy.compatibleIds.includes(normalizedRuntimeAuthOwner ?? "");
-    if (params.resolution.routes.length > 1 && runtimeAuthOwnerIsCompatible && !configuredRoute) {
+    const hostHasNoCredentialToHonor =
+      params.allowNativeAuthOnSingleRoute === true &&
+      params.sourcePlan.kind === "automatic" &&
+      params.sourcePlan.orderedProfiles.length === 0 &&
+      params.sourcePlan.fallback === undefined;
+    if (
+      runtimeAuthOwnerIsCompatible &&
+      !configuredRoute &&
+      (params.resolution.routes.length > 1 || hostHasNoCredentialToHonor)
+    ) {
       return { kind: "deferred", reason: "runtime-auth-owner", routeSupport };
     }
     return reject(
diff --git a/src/agents/runtime-plan/prepare-auth.ts b/src/agents/runtime-plan/prepare-auth.ts
index 37fdabe091dc..ac7f9a5ddc01 100644
--- a/src/agents/runtime-plan/prepare-auth.ts
+++ b/src/agents/runtime-plan/prepare-auth.ts
@@ -520,6 +520,9 @@ export function prepareAgentRuntimeAuth(
     sourcePlan,
     configuredAuthMode: automaticRouteAuthMode,
     ...(runtimeAuthOwner ? { runtimeAuthOwner } : {}),
+    ...(runtimeAuthOwner && configuredProvider === undefined
+      ? { allowNativeAuthOnSingleRoute: true }
+      : {}),
   });
   if (routeAuthDecision.kind === "deferred") {
     const plan = buildAgentRuntimeAuthPlan({