diff --git a/docs/plugins/sdk-agent-harness.md b/docs/plugins/sdk-agent-harness.md
index c1b5a84c44f..e1b0bf26d6b 100644
--- a/docs/plugins/sdk-agent-harness.md
+++ b/docs/plugins/sdk-agent-harness.md
@@ -99,9 +99,9 @@ OpenClaw may fall back to PI when the selected plugin harness fails before a
 turn has produced side effects. Set `OPENCLAW_AGENT_HARNESS_FALLBACK=none` or
 `embeddedHarness.fallback: "none"` to make that fallback a hard failure instead.
 
-The bundled Codex plugin registers `codex` as its harness id. For compatibility,
-`codex-app-server` and `app-server` also resolve to that same harness when you
-set `OPENCLAW_AGENT_RUNTIME` manually.
+The bundled Codex plugin registers `codex` as its harness id. Core treats that
+as an ordinary plugin harness id; Codex-specific aliases belong in the plugin
+or operator config, not in the shared runtime selector.
 
 ## Provider plus harness pairing
 
diff --git a/extensions/codex/harness.ts b/extensions/codex/harness.ts
index aa91b3c6821..c77b357dda3 100644
--- a/extensions/codex/harness.ts
+++ b/extensions/codex/harness.ts
@@ -10,7 +10,7 @@ import { runCodexAppServerAttempt } from "./src/app-server/run-attempt.js";
 import { clearCodexAppServerBinding } from "./src/app-server/session-binding.js";
 import { clearSharedCodexAppServerClient } from "./src/app-server/shared-client.js";
 
-const DEFAULT_CODEX_HARNESS_PROVIDER_IDS = new Set(["codex", "openai-codex"]);
+const DEFAULT_CODEX_HARNESS_PROVIDER_IDS = new Set(["codex"]);
 
 export type { CodexAppServerListModelsOptions, CodexAppServerModel, CodexAppServerModelListResult };
 export { listCodexAppServerModels };
diff --git a/extensions/codex/index.test.ts b/extensions/codex/index.test.ts
index 37c405a91c1..d61151c2c8d 100644
--- a/extensions/codex/index.test.ts
+++ b/extensions/codex/index.test.ts
@@ -1,6 +1,7 @@
 import fs from "node:fs";
 import { describe, expect, it, vi } from "vitest";
 import { createTestPluginApi } from "../../test/helpers/plugins/plugin-api.js";
+import { createCodexAppServerAgentHarness } from "./harness.js";
 import plugin from "./index.js";
 
 describe("codex plugin", () => {
@@ -42,4 +43,20 @@ describe("codex plugin", () => {
       description: "Inspect and control the Codex app-server harness",
     });
   });
+
+  it("only claims the codex provider by default", () => {
+    const harness = createCodexAppServerAgentHarness();
+
+    expect(
+      harness.supports({ provider: "codex", modelId: "gpt-5.4", requestedRuntime: "auto" })
+        .supported,
+    ).toBe(true);
+    expect(
+      harness.supports({
+        provider: "openai-codex",
+        modelId: "gpt-5.4",
+        requestedRuntime: "auto",
+      }),
+    ).toMatchObject({ supported: false });
+  });
 });
diff --git a/src/agents/pi-embedded-runner/run/backend.test.ts b/src/agents/pi-embedded-runner/run/backend.test.ts
index e659e555303..a41a85465e5 100644
--- a/src/agents/pi-embedded-runner/run/backend.test.ts
+++ b/src/agents/pi-embedded-runner/run/backend.test.ts
@@ -10,12 +10,11 @@ describe("resolveEmbeddedAgentRuntime", () => {
     expect(resolveEmbeddedAgentRuntime({ OPENCLAW_AGENT_RUNTIME: "pi" })).toBe("pi");
   });
 
-  it("accepts codex app-server aliases", () => {
-    expect(resolveEmbeddedAgentRuntime({ OPENCLAW_AGENT_RUNTIME: "codex-app-server" })).toBe(
-      "codex",
-    );
+  it("preserves plugin harness ids without core-owned aliases", () => {
     expect(resolveEmbeddedAgentRuntime({ OPENCLAW_AGENT_RUNTIME: "codex" })).toBe("codex");
-    expect(resolveEmbeddedAgentRuntime({ OPENCLAW_AGENT_RUNTIME: "app-server" })).toBe("codex");
+    expect(resolveEmbeddedAgentRuntime({ OPENCLAW_AGENT_RUNTIME: "codex-app-server" })).toBe(
+      "codex-app-server",
+    );
   });
 
   it("accepts auto mode", () => {
diff --git a/src/agents/pi-embedded-runner/runtime.ts b/src/agents/pi-embedded-runner/runtime.ts
index 639d6adc17a..9c85704856c 100644
--- a/src/agents/pi-embedded-runner/runtime.ts
+++ b/src/agents/pi-embedded-runner/runtime.ts
@@ -9,9 +9,6 @@ export function normalizeEmbeddedAgentRuntime(raw: string | undefined): Embedded
   if (value === "pi") {
     return "pi";
   }
-  if (value === "codex" || value === "codex-app-server" || value === "app-server") {
-    return "codex";
-  }
   if (value === "auto") {
     return "auto";
   }