diff --git a/packages/adapter-utils/src/index.ts b/packages/adapter-utils/src/index.ts
index 653c07e936..2690cf5fbe 100644
--- a/packages/adapter-utils/src/index.ts
+++ b/packages/adapter-utils/src/index.ts
@@ -116,6 +116,7 @@ export {
   PAPERCLIP_RUNNER_IDLE_TIMEOUT_DEFAULT_MS,
   PAPERCLIP_RUNNER_IDLE_TIMEOUT_MAX_MS,
   PAPERCLIP_RUNNER_DEFAULT_MODELS,
+  PAPERCLIP_RUNNER_ACPX_DEFAULT_MODELS,
   PAPERCLIP_RUNNER_PERMISSION_CAPABILITIES,
   isPaperclipRunnerProvider,
   resolvePaperclipRunnerIdleTimeoutMs,
diff --git a/packages/adapter-utils/src/paperclip-runner-permissions.ts b/packages/adapter-utils/src/paperclip-runner-permissions.ts
index 306cbffa74..e7bfea9329 100644
--- a/packages/adapter-utils/src/paperclip-runner-permissions.ts
+++ b/packages/adapter-utils/src/paperclip-runner-permissions.ts
@@ -16,6 +16,12 @@ export const PAPERCLIP_RUNNER_DEFAULT_MODELS = {
   opencode: "openrouter/deepseek/deepseek-v4-flash-0731",
 } as const;
 
+export const PAPERCLIP_RUNNER_ACPX_DEFAULT_MODELS = {
+  claude: PAPERCLIP_RUNNER_DEFAULT_MODELS.acpx,
+  codex: PAPERCLIP_RUNNER_DEFAULT_MODELS.codex,
+  pi: "openrouter/deepseek/deepseek-v4-flash-0731",
+} as const;
+
 export interface PaperclipRunnerPermissionOption<
   TMode extends string = string,
 > {
diff --git a/packages/adapter-utils/src/server-utils.ts b/packages/adapter-utils/src/server-utils.ts
index 93bab9ae63..83208bf211 100644
--- a/packages/adapter-utils/src/server-utils.ts
+++ b/packages/adapter-utils/src/server-utils.ts
@@ -15,6 +15,7 @@ import { redactCommandText } from "./command-redaction.js";
 import { paperclipChatFilePreparationDelivery } from "./chat-file-delivery.js";
 import {
   PAPERCLIP_RUNNER_PERMISSION_CAPABILITIES,
+  PAPERCLIP_RUNNER_ACPX_DEFAULT_MODELS,
   resolvePaperclipRunnerModel,
   normalizeLegacyRunnerProvider,
 } from "./paperclip-runner-permissions.js";
@@ -4113,7 +4114,11 @@ export function normalizePaperclipRunnerAdapterConfig(
   }
   if (next.provider === "acpx") {
     next.acpxAgent ??= "claude";
-    next.model = resolvePaperclipRunnerModel("acpx", config.model);
+    const defaultModel = next.acpxAgent === "pi"
+      ? PAPERCLIP_RUNNER_ACPX_DEFAULT_MODELS.pi
+      : PAPERCLIP_RUNNER_ACPX_DEFAULT_MODELS.claude;
+    next.model = typeof config.model === "string" && config.model.trim().length > 0
+      ? config.model.trim() : defaultModel;
   }
   return normalizePaperclipOperationalSkillPreference(adapterType, next);
 }
diff --git a/server/src/__tests__/agents-paperclip-runner-skills.test.ts b/server/src/__tests__/agents-paperclip-runner-skills.test.ts
index eb7bb633ac..41e826a00f 100644
--- a/server/src/__tests__/agents-paperclip-runner-skills.test.ts
+++ b/server/src/__tests__/agents-paperclip-runner-skills.test.ts
@@ -5,6 +5,7 @@ import {
   PAPERCLIP_OPERATIONAL_SKILL_KEY,
   resolveLegacyPaperclipDesiredSkillNames,
 } from "@paperclipai/adapter-utils/server-utils";
+import { resolvePaperclipRunnerProviderProfile } from "../services/native-runtime/provider-profile.js";
 
 const legacyConfig = {
   paperclipSkillSync: {
@@ -13,6 +14,16 @@ const legacyConfig = {
 };
 
 describe("paperclip_runner operational skill normalization", () => {
+  it.each([undefined, "", "  "])("qualifies Pi's default model at persistence and execution (%s)", (model) => {
+    const input = { provider: "acpx", acpxAgent: "pi", model };
+    const normalized = normalizePaperclipRunnerAdapterConfig("paperclip_runner", input);
+    expect(normalized.model).toBe("openrouter/deepseek/deepseek-v4-flash-0731");
+    expect(resolvePaperclipRunnerProviderProfile(normalized)).toMatchObject({ provider: "acpx", acpxAgent: "pi", model: normalized.model });
+    expect(resolvePaperclipRunnerProviderProfile(input)).toMatchObject({ provider: "acpx", acpxAgent: "pi", model: normalized.model });
+    const explicit = normalizePaperclipRunnerAdapterConfig("paperclip_runner", { ...input, model: "unqualified-model" });
+    expect(explicit.model).toBe("unqualified-model");
+    expect(() => resolvePaperclipRunnerProviderProfile(explicit)).toThrow("requires exact model");
+  });
   it("applies full-auto native runner defaults at persistence boundaries", () => {
     expect(normalizePaperclipRunnerAdapterConfig("paperclip_runner", {})).toEqual({
       provider: "codex",
diff --git a/server/src/services/native-runtime/provider-profile.ts b/server/src/services/native-runtime/provider-profile.ts
index 19064f197b..2eb5f96656 100644
--- a/server/src/services/native-runtime/provider-profile.ts
+++ b/server/src/services/native-runtime/provider-profile.ts
@@ -1,6 +1,7 @@
 import {
   isPaperclipRunnerProvider,
   PAPERCLIP_RUNNER_PERMISSION_CAPABILITIES,
+  PAPERCLIP_RUNNER_ACPX_DEFAULT_MODELS,
   resolvePaperclipRunnerPermissionMode,
   type PaperclipRunnerProvider,
 } from "@paperclipai/adapter-utils";
@@ -14,11 +15,7 @@ export const DEFAULT_OPENCODE_RUNNER_MODEL =
   "openrouter/deepseek/deepseek-v4-flash-0731" as const;
 export const CLAUDE_MANAGED_BETA_VERSION = "managed-agents-2026-04-01" as const;
 
-export const QUALIFIED_ACPX_RUNNER_MODELS = {
-  claude: "claude-sonnet-5",
-  codex: "gpt-5.6-sol",
-  pi: "openrouter/deepseek/deepseek-v4-flash-0731",
-} as const;
+export const QUALIFIED_ACPX_RUNNER_MODELS = PAPERCLIP_RUNNER_ACPX_DEFAULT_MODELS;
 
 export type QualifiedPaperclipRunnerAcpxAgent =
   keyof typeof QUALIFIED_ACPX_RUNNER_MODELS;
@@ -412,7 +409,7 @@ export function resolvePaperclipRunnerProviderProfile(
     );
   }
   const qualifiedModel = QUALIFIED_ACPX_RUNNER_MODELS[acpxAgent];
-  if (acpxAgent !== "claude" && model !== qualifiedModel) {
+  if (acpxAgent !== "claude" && model !== null && model !== qualifiedModel) {
     throw new PaperclipRunnerProviderProfileError(
       "paperclip_runner_acpx_model_unqualified",
       `Paperclip Runner ACPX ${acpxAgent} requires exact model ${qualifiedModel}.`,