diff --git a/src/agents/pi-embedded-helpers.test.ts b/src/agents/pi-embedded-helpers.test.ts
index a709351e6..97a332224 100644
--- a/src/agents/pi-embedded-helpers.test.ts
+++ b/src/agents/pi-embedded-helpers.test.ts
@@ -1,7 +1,11 @@
 import type { AssistantMessage } from "@mariozechner/pi-ai";
 import { describe, expect, it } from "vitest";
 
-import { isRateLimitAssistantError } from "./pi-embedded-helpers.js";
+import {
+  isRateLimitAssistantError,
+  pickFallbackThinkingLevel,
+} from "./pi-embedded-helpers.js";
+import type { ThinkLevel } from "../auto-reply/thinking.js";
 
 const asAssistant = (overrides: Partial<AssistantMessage>) =>
   ({ role: "assistant", stopReason: "error", ...overrides }) as AssistantMessage;
@@ -30,3 +34,34 @@ describe("isRateLimitAssistantError", () => {
     expect(isRateLimitAssistantError(msg)).toBe(false);
   });
 });
+
+describe("pickFallbackThinkingLevel", () => {
+  it("selects the first supported thinking level", () => {
+    const attempted = new Set<ThinkLevel>(["low"]);
+    const next = pickFallbackThinkingLevel({
+      message:
+        "Unsupported value: 'low' is not supported with the 'gpt-5.2-pro' model. Supported values are: 'medium', 'high', and 'xhigh'.",
+      attempted,
+    });
+    expect(next).toBe("medium");
+  });
+
+  it("skips already attempted levels", () => {
+    const attempted = new Set<ThinkLevel>(["low", "medium"]);
+    const next = pickFallbackThinkingLevel({
+      message:
+        "Supported values are: 'medium', 'high', and 'xhigh'.",
+      attempted,
+    });
+    expect(next).toBe("high");
+  });
+
+  it("returns undefined when no supported values are found", () => {
+    const attempted = new Set<ThinkLevel>(["low"]);
+    const next = pickFallbackThinkingLevel({
+      message: "Request failed.",
+      attempted,
+    });
+    expect(next).toBeUndefined();
+  });
+});
diff --git a/src/agents/pi-embedded-helpers.ts b/src/agents/pi-embedded-helpers.ts
index e4d598463..79808d9e2 100644
--- a/src/agents/pi-embedded-helpers.ts
+++ b/src/agents/pi-embedded-helpers.ts
@@ -6,6 +6,7 @@ import type {
   AgentToolResult,
 } from "@mariozechner/pi-agent-core";
 import type { AssistantMessage } from "@mariozechner/pi-ai";
+import { normalizeThinkLevel, type ThinkLevel } from "../auto-reply/thinking.js";
 
 import { sanitizeContentBlocksImages } from "./tool-images.js";
 import type { WorkspaceBootstrapFile } from "./workspace.js";
@@ -118,3 +119,38 @@ export function isRateLimitAssistantError(
   if (!raw) return false;
   return /rate[_ ]limit|too many requests|429/.test(raw);
 }
+
+function extractSupportedValues(raw: string): string[] {
+  const match =
+    raw.match(/supported values are:\s*([^\n.]+)/i) ??
+    raw.match(/supported values:\s*([^\n.]+)/i);
+  if (!match?.[1]) return [];
+  const fragment = match[1];
+  const quoted = Array.from(fragment.matchAll(/['"]([^'"]+)['"]/g)).map(
+    (entry) => entry[1]?.trim(),
+  );
+  if (quoted.length > 0) {
+    return quoted.filter((entry): entry is string => Boolean(entry));
+  }
+  return fragment
+    .split(/,|\band\b/gi)
+    .map((entry) => entry.replace(/^[^a-zA-Z]+|[^a-zA-Z]+$/g, "").trim())
+    .filter(Boolean);
+}
+
+export function pickFallbackThinkingLevel(params: {
+  message?: string;
+  attempted: Set<ThinkLevel>;
+}): ThinkLevel | undefined {
+  const raw = params.message?.trim();
+  if (!raw) return undefined;
+  const supported = extractSupportedValues(raw);
+  if (supported.length === 0) return undefined;
+  for (const entry of supported) {
+    const normalized = normalizeThinkLevel(entry);
+    if (!normalized) continue;
+    if (params.attempted.has(normalized)) continue;
+    return normalized;
+  }
+  return undefined;
+}
diff --git a/src/agents/pi-embedded-runner.ts b/src/agents/pi-embedded-runner.ts
index b20c9d83f..9b33fdda8 100644
--- a/src/agents/pi-embedded-runner.ts
+++ b/src/agents/pi-embedded-runner.ts
@@ -33,6 +33,7 @@ import {
   ensureSessionHeader,
   formatAssistantErrorText,
   isRateLimitAssistantError,
+  pickFallbackThinkingLevel,
   sanitizeSessionMessagesImages,
 } from "./pi-embedded-helpers.js";
 import {
@@ -319,22 +320,27 @@ export async function runEmbeddedPiAgent(params: {
       const apiKey = await getApiKeyForModel(model, authStorage);
       authStorage.setRuntimeApiKey(model.provider, apiKey);
 
-      const thinkingLevel = mapThinkingLevel(params.thinkLevel);
+      let thinkLevel = params.thinkLevel ?? "off";
+      const attemptedThinking = new Set<ThinkLevel>();
 
-      log.debug(
-        `embedded run start: runId=${params.runId} sessionId=${params.sessionId} provider=${provider} model=${modelId} surface=${params.surface ?? "unknown"}`,
-      );
+      while (true) {
+        const thinkingLevel = mapThinkingLevel(thinkLevel);
+        attemptedThinking.add(thinkLevel);
 
-      await fs.mkdir(resolvedWorkspace, { recursive: true });
-      await ensureSessionHeader({
-        sessionFile: params.sessionFile,
-        sessionId: params.sessionId,
-        cwd: resolvedWorkspace,
-      });
+        log.debug(
+          `embedded run start: runId=${params.runId} sessionId=${params.sessionId} provider=${provider} model=${modelId} thinking=${thinkLevel} surface=${params.surface ?? "unknown"}`,
+        );
 
-      let restoreSkillEnv: (() => void) | undefined;
-      process.chdir(resolvedWorkspace);
-      try {
+        await fs.mkdir(resolvedWorkspace, { recursive: true });
+        await ensureSessionHeader({
+          sessionFile: params.sessionFile,
+          sessionId: params.sessionId,
+          cwd: resolvedWorkspace,
+        });
+
+        let restoreSkillEnv: (() => void) | undefined;
+        process.chdir(resolvedWorkspace);
+        try {
         const shouldLoadSkillEntries =
           !params.skillsSnapshot || !params.skillsSnapshot.resolvedSkills;
         const skillEntries = shouldLoadSkillEntries
@@ -391,7 +397,7 @@ export async function runEmbeddedPiAgent(params: {
         const systemPrompt = buildSystemPrompt({
           appendPrompt: buildAgentSystemPromptAppend({
             workspaceDir: resolvedWorkspace,
-            defaultThinkLevel: params.thinkLevel,
+            defaultThinkLevel: thinkLevel,
             extraSystemPrompt: params.extraSystemPrompt,
             ownerNumbers: params.ownerNumbers,
             reasoningTagHint,
@@ -542,6 +548,20 @@ export async function runEmbeddedPiAgent(params: {
           params.abortSignal?.removeEventListener?.("abort", onAbort);
         }
         if (promptError && !aborted) {
+          const fallbackThinking = pickFallbackThinkingLevel({
+            message:
+              promptError instanceof Error
+                ? promptError.message
+                : String(promptError),
+            attempted: attemptedThinking,
+          });
+          if (fallbackThinking) {
+            log.warn(
+              `unsupported thinking level for ${provider}/${modelId}; retrying with ${fallbackThinking}`,
+            );
+            thinkLevel = fallbackThinking;
+            continue;
+          }
           throw promptError;
         }
 
@@ -552,6 +572,18 @@ export async function runEmbeddedPiAgent(params: {
           | AssistantMessage
           | undefined;
 
+        const fallbackThinking = pickFallbackThinkingLevel({
+          message: lastAssistant?.errorMessage,
+          attempted: attemptedThinking,
+        });
+        if (fallbackThinking && !aborted) {
+          log.warn(
+            `unsupported thinking level for ${provider}/${modelId}; retrying with ${fallbackThinking}`,
+          );
+          thinkLevel = fallbackThinking;
+          continue;
+        }
+
         const fallbackConfigured =
           (params.config?.agent?.modelFallbacks?.length ?? 0) > 0;
         if (fallbackConfigured && isRateLimitAssistantError(lastAssistant)) {
@@ -631,9 +663,10 @@ export async function runEmbeddedPiAgent(params: {
             aborted,
           },
         };
-      } finally {
-        restoreSkillEnv?.();
-        process.chdir(prevCwd);
+        } finally {
+          restoreSkillEnv?.();
+          process.chdir(prevCwd);
+        }
       }
     }),
   );