diff --git a/src/agents/auth-profiles.ts b/src/agents/auth-profiles.ts
index 77549296d..099d04d47 100644
--- a/src/agents/auth-profiles.ts
+++ b/src/agents/auth-profiles.ts
@@ -842,6 +842,57 @@ export function calculateAuthProfileCooldownMs(errorCount: number): number {
   );
 }
 
+type ResolvedAuthCooldownConfig = {
+  billingBackoffMs: number;
+  billingMaxMs: number;
+  failureWindowMs: number;
+};
+
+function resolveAuthCooldownConfig(params: {
+  cfg?: ClawdbotConfig;
+  providerId: string;
+}): ResolvedAuthCooldownConfig {
+  const defaults = {
+    billingBackoffHours: 5,
+    billingMaxHours: 24,
+    failureWindowHours: 24,
+  } as const;
+
+  const resolveHours = (value: unknown, fallback: number) =>
+    typeof value === "number" && Number.isFinite(value) && value > 0
+      ? value
+      : fallback;
+
+  const cooldowns = params.cfg?.auth?.cooldowns;
+  const billingOverride = (() => {
+    const map = cooldowns?.billingBackoffHoursByProvider;
+    if (!map) return undefined;
+    for (const [key, value] of Object.entries(map)) {
+      if (normalizeProviderId(key) === params.providerId) return value;
+    }
+    return undefined;
+  })();
+
+  const billingBackoffHours = resolveHours(
+    billingOverride ?? cooldowns?.billingBackoffHours,
+    defaults.billingBackoffHours,
+  );
+  const billingMaxHours = resolveHours(
+    cooldowns?.billingMaxHours,
+    defaults.billingMaxHours,
+  );
+  const failureWindowHours = resolveHours(
+    cooldowns?.failureWindowHours,
+    defaults.failureWindowHours,
+  );
+
+  return {
+    billingBackoffMs: billingBackoffHours * 60 * 60 * 1000,
+    billingMaxMs: billingMaxHours * 60 * 60 * 1000,
+    failureWindowMs: failureWindowHours * 60 * 60 * 1000,
+  };
+}
+
 function calculateAuthProfileBillingDisableMsWithConfig(params: {
   errorCount: number;
   baseMs: number;
@@ -872,6 +923,49 @@ export function resolveProfileUnusableUntilForDisplay(
   return resolveProfileUnusableUntil(stats);
 }
 
+function computeNextProfileUsageStats(params: {
+  existing: ProfileUsageStats;
+  now: number;
+  reason: AuthProfileFailureReason;
+  cfgResolved: ResolvedAuthCooldownConfig;
+}): ProfileUsageStats {
+  const windowMs = params.cfgResolved.failureWindowMs;
+  const windowExpired =
+    typeof params.existing.lastFailureAt === "number" &&
+    params.existing.lastFailureAt > 0 &&
+    params.now - params.existing.lastFailureAt > windowMs;
+
+  const baseErrorCount = windowExpired ? 0 : (params.existing.errorCount ?? 0);
+  const nextErrorCount = baseErrorCount + 1;
+  const failureCounts = windowExpired
+    ? {}
+    : { ...params.existing.failureCounts };
+  failureCounts[params.reason] = (failureCounts[params.reason] ?? 0) + 1;
+
+  const updatedStats: ProfileUsageStats = {
+    ...params.existing,
+    errorCount: nextErrorCount,
+    failureCounts,
+    lastFailureAt: params.now,
+  };
+
+  if (params.reason === "billing") {
+    const billingCount = failureCounts.billing ?? 1;
+    const backoffMs = calculateAuthProfileBillingDisableMsWithConfig({
+      errorCount: billingCount,
+      baseMs: params.cfgResolved.billingBackoffMs,
+      maxMs: params.cfgResolved.billingMaxMs,
+    });
+    updatedStats.disabledUntil = params.now + backoffMs;
+    updatedStats.disabledReason = "billing";
+  } else {
+    const backoffMs = calculateAuthProfileCooldownMs(nextErrorCount);
+    updatedStats.cooldownUntil = params.now + backoffMs;
+  }
+
+  return updatedStats;
+}
+
 /**
  * Mark a profile as failed for a specific reason. Billing failures are treated
  * as "disabled" (longer backoff) vs the regular cooldown window.
@@ -884,44 +978,6 @@ export async function markAuthProfileFailure(params: {
   agentDir?: string;
 }): Promise<void> {
   const { store, profileId, reason, agentDir, cfg } = params;
-  const defaults = {
-    billingBackoffHours: 5,
-    billingMaxHours: 24,
-    failureWindowHours: 24,
-  } as const;
-  const resolveHours = (value: unknown, fallback: number) =>
-    typeof value === "number" && Number.isFinite(value) && value > 0
-      ? value
-      : fallback;
-  const resolveCooldownConfig = (providerId: string) => {
-    const cooldowns = cfg?.auth?.cooldowns;
-    const billingOverride = (() => {
-      const map = cooldowns?.billingBackoffHoursByProvider;
-      if (!map) return undefined;
-      for (const [key, value] of Object.entries(map)) {
-        if (normalizeProviderId(key) === providerId) return value;
-      }
-      return undefined;
-    })();
-    const billingBackoffHours = resolveHours(
-      billingOverride ?? cooldowns?.billingBackoffHours,
-      defaults.billingBackoffHours,
-    );
-    const billingMaxHours = resolveHours(
-      cooldowns?.billingMaxHours,
-      defaults.billingMaxHours,
-    );
-    const failureWindowHours = resolveHours(
-      cooldowns?.failureWindowHours,
-      defaults.failureWindowHours,
-    );
-    return {
-      billingBackoffMs: billingBackoffHours * 60 * 60 * 1000,
-      billingMaxMs: billingMaxHours * 60 * 60 * 1000,
-      failureWindowMs: failureWindowHours * 60 * 60 * 1000,
-    };
-  };
-
   const updated = await updateAuthProfileStoreWithLock({
     agentDir,
     updater: (freshStore) => {
@@ -932,41 +988,17 @@ export async function markAuthProfileFailure(params: {
 
       const now = Date.now();
       const providerKey = normalizeProviderId(profile.provider);
-      const cfgResolved = resolveCooldownConfig(providerKey);
+      const cfgResolved = resolveAuthCooldownConfig({
+        cfg,
+        providerId: providerKey,
+      });
 
-      const windowMs = cfgResolved.failureWindowMs;
-      const windowExpired =
-        typeof existing.lastFailureAt === "number" &&
-        existing.lastFailureAt > 0 &&
-        now - existing.lastFailureAt > windowMs;
-
-      const baseErrorCount = windowExpired ? 0 : (existing.errorCount ?? 0);
-      const nextErrorCount = baseErrorCount + 1;
-      const failureCounts = windowExpired ? {} : { ...existing.failureCounts };
-      failureCounts[reason] = (failureCounts[reason] ?? 0) + 1;
-
-      const updatedStats: ProfileUsageStats = {
-        ...existing,
-        errorCount: nextErrorCount,
-        failureCounts,
-        lastFailureAt: now,
-      };
-
-      if (reason === "billing") {
-        const billingCount = failureCounts.billing ?? 1;
-        const backoffMs = calculateAuthProfileBillingDisableMsWithConfig({
-          errorCount: billingCount,
-          baseMs: cfgResolved.billingBackoffMs,
-          maxMs: cfgResolved.billingMaxMs,
-        });
-        updatedStats.disabledUntil = now + backoffMs;
-        updatedStats.disabledReason = "billing";
-      } else {
-        const backoffMs = calculateAuthProfileCooldownMs(nextErrorCount);
-        updatedStats.cooldownUntil = now + backoffMs;
-      }
-
-      freshStore.usageStats[profileId] = updatedStats;
+      freshStore.usageStats[profileId] = computeNextProfileUsageStats({
+        existing,
+        now,
+        reason,
+        cfgResolved,
+      });
       return true;
     },
   });
@@ -982,38 +1014,17 @@ export async function markAuthProfileFailure(params: {
   const providerKey = normalizeProviderId(
     store.profiles[profileId]?.provider ?? "",
   );
-  const cfgResolved = resolveCooldownConfig(providerKey);
-  const windowMs = cfgResolved.failureWindowMs;
-  const windowExpired =
-    typeof existing.lastFailureAt === "number" &&
-    existing.lastFailureAt > 0 &&
-    now - existing.lastFailureAt > windowMs;
-  const baseErrorCount = windowExpired ? 0 : (existing.errorCount ?? 0);
-  const nextErrorCount = baseErrorCount + 1;
-  const failureCounts = windowExpired ? {} : { ...existing.failureCounts };
-  failureCounts[reason] = (failureCounts[reason] ?? 0) + 1;
+  const cfgResolved = resolveAuthCooldownConfig({
+    cfg,
+    providerId: providerKey,
+  });
 
-  const updatedStats: ProfileUsageStats = {
-    ...existing,
-    errorCount: nextErrorCount,
-    failureCounts,
-    lastFailureAt: now,
-  };
-  if (reason === "billing") {
-    const billingCount = failureCounts.billing ?? 1;
-    const backoffMs = calculateAuthProfileBillingDisableMsWithConfig({
-      errorCount: billingCount,
-      baseMs: cfgResolved.billingBackoffMs,
-      maxMs: cfgResolved.billingMaxMs,
-    });
-    updatedStats.disabledUntil = now + backoffMs;
-    updatedStats.disabledReason = "billing";
-  } else {
-    const backoffMs = calculateAuthProfileCooldownMs(nextErrorCount);
-    updatedStats.cooldownUntil = now + backoffMs;
-  }
-
-  store.usageStats[profileId] = updatedStats;
+  store.usageStats[profileId] = computeNextProfileUsageStats({
+    existing,
+    now,
+    reason,
+    cfgResolved,
+  });
   saveAuthProfileStore(store, agentDir);
 }
 
diff --git a/src/agents/failover-error.test.ts b/src/agents/failover-error.test.ts
new file mode 100644
index 000000000..a94fb8b3f
--- /dev/null
+++ b/src/agents/failover-error.test.ts
@@ -0,0 +1,44 @@
+import { describe, expect, it } from "vitest";
+import {
+  coerceToFailoverError,
+  describeFailoverError,
+  resolveFailoverReasonFromError,
+} from "./failover-error.js";
+
+describe("failover-error", () => {
+  it("infers failover reason from HTTP status", () => {
+    expect(resolveFailoverReasonFromError({ status: 402 })).toBe("billing");
+    expect(resolveFailoverReasonFromError({ statusCode: "429" })).toBe(
+      "rate_limit",
+    );
+    expect(resolveFailoverReasonFromError({ status: 403 })).toBe("auth");
+    expect(resolveFailoverReasonFromError({ status: 408 })).toBe("timeout");
+  });
+
+  it("infers timeout from common node error codes", () => {
+    expect(resolveFailoverReasonFromError({ code: "ETIMEDOUT" })).toBe(
+      "timeout",
+    );
+    expect(resolveFailoverReasonFromError({ code: "ECONNRESET" })).toBe(
+      "timeout",
+    );
+  });
+
+  it("coerces failover-worthy errors into FailoverError with metadata", () => {
+    const err = coerceToFailoverError("credit balance too low", {
+      provider: "anthropic",
+      model: "claude-opus-4-5",
+    });
+    expect(err?.name).toBe("FailoverError");
+    expect(err?.reason).toBe("billing");
+    expect(err?.status).toBe(402);
+    expect(err?.provider).toBe("anthropic");
+    expect(err?.model).toBe("claude-opus-4-5");
+  });
+
+  it("describes non-Error values consistently", () => {
+    const described = describeFailoverError(123);
+    expect(described.message).toBe("123");
+    expect(described.reason).toBeUndefined();
+  });
+});
diff --git a/src/agents/failover-error.ts b/src/agents/failover-error.ts
index fcebd1e87..fdadab0a7 100644
--- a/src/agents/failover-error.ts
+++ b/src/agents/failover-error.ts
@@ -1,4 +1,7 @@
-import type { FailoverReason } from "./pi-embedded-helpers.js";
+import {
+  classifyFailoverReason,
+  type FailoverReason,
+} from "./pi-embedded-helpers.js";
 
 export class FailoverError extends Error {
   readonly reason: FailoverReason;
@@ -51,3 +54,116 @@ export function resolveFailoverStatus(
       return undefined;
   }
 }
+
+function getStatusCode(err: unknown): number | undefined {
+  if (!err || typeof err !== "object") return undefined;
+  const candidate =
+    (err as { status?: unknown; statusCode?: unknown }).status ??
+    (err as { statusCode?: unknown }).statusCode;
+  if (typeof candidate === "number") return candidate;
+  if (typeof candidate === "string" && /^\d+$/.test(candidate)) {
+    return Number(candidate);
+  }
+  return undefined;
+}
+
+function getErrorCode(err: unknown): string | undefined {
+  if (!err || typeof err !== "object") return undefined;
+  const candidate = (err as { code?: unknown }).code;
+  if (typeof candidate !== "string") return undefined;
+  const trimmed = candidate.trim();
+  return trimmed ? trimmed : undefined;
+}
+
+function getErrorMessage(err: unknown): string {
+  if (err instanceof Error) return err.message;
+  if (typeof err === "string") return err;
+  if (
+    typeof err === "number" ||
+    typeof err === "boolean" ||
+    typeof err === "bigint"
+  ) {
+    return String(err);
+  }
+  if (typeof err === "symbol") return err.description ?? "";
+  if (err && typeof err === "object") {
+    const message = (err as { message?: unknown }).message;
+    if (typeof message === "string") return message;
+  }
+  return "";
+}
+
+export function resolveFailoverReasonFromError(
+  err: unknown,
+): FailoverReason | null {
+  if (isFailoverError(err)) return err.reason;
+
+  const status = getStatusCode(err);
+  if (status === 402) return "billing";
+  if (status === 429) return "rate_limit";
+  if (status === 401 || status === 403) return "auth";
+  if (status === 408) return "timeout";
+
+  const code = (getErrorCode(err) ?? "").toUpperCase();
+  if (
+    ["ETIMEDOUT", "ESOCKETTIMEDOUT", "ECONNRESET", "ECONNABORTED"].includes(
+      code,
+    )
+  ) {
+    return "timeout";
+  }
+
+  const message = getErrorMessage(err);
+  if (!message) return null;
+  return classifyFailoverReason(message);
+}
+
+export function describeFailoverError(err: unknown): {
+  message: string;
+  reason?: FailoverReason;
+  status?: number;
+  code?: string;
+} {
+  if (isFailoverError(err)) {
+    return {
+      message: err.message,
+      reason: err.reason,
+      status: err.status,
+      code: err.code,
+    };
+  }
+  const message = getErrorMessage(err) || String(err);
+  return {
+    message,
+    reason: resolveFailoverReasonFromError(err) ?? undefined,
+    status: getStatusCode(err),
+    code: getErrorCode(err),
+  };
+}
+
+export function coerceToFailoverError(
+  err: unknown,
+  context?: {
+    provider?: string;
+    model?: string;
+    profileId?: string;
+  },
+): FailoverError | null {
+  if (isFailoverError(err)) return err;
+  const reason = resolveFailoverReasonFromError(err);
+  if (!reason) return null;
+
+  const message = getErrorMessage(err) || String(err);
+  const status = getStatusCode(err) ?? resolveFailoverStatus(reason);
+  const code = getErrorCode(err);
+
+  return new FailoverError(message, {
+    reason,
+    provider: context?.provider,
+    model: context?.model,
+    profileId: context?.profileId,
+    status,
+    code,
+    cause: err instanceof Error ? err : undefined,
+  });
+}
diff --git a/src/agents/model-fallback.ts b/src/agents/model-fallback.ts
index 607d69094..ed8188842 100644
--- a/src/agents/model-fallback.ts
+++ b/src/agents/model-fallback.ts
@@ -1,6 +1,10 @@
 import type { ClawdbotConfig } from "../config/config.js";
 import { DEFAULT_MODEL, DEFAULT_PROVIDER } from "./defaults.js";
-import { type FailoverError, isFailoverError } from "./failover-error.js";
+import {
+  coerceToFailoverError,
+  describeFailoverError,
+  isFailoverError,
+} from "./failover-error.js";
 import {
   buildModelAliasIndex,
   modelKey,
@@ -9,7 +13,6 @@ import {
   resolveModelRefFromString,
 } from "./model-selection.js";
 import type { FailoverReason } from "./pi-embedded-helpers.js";
-import { isFailoverErrorMessage } from "./pi-embedded-helpers.js";
 
 type ModelCandidate = {
   provider: string;
@@ -36,81 +39,6 @@ function isAbortError(err: unknown): boolean {
   return message.includes("aborted");
 }
 
-function getStatusCode(err: unknown): number | null {
-  if (!err || typeof err !== "object") return null;
-  const candidate =
-    (err as { status?: unknown; statusCode?: unknown }).status ??
-    (err as { statusCode?: unknown }).statusCode;
-  if (typeof candidate === "number") return candidate;
-  if (typeof candidate === "string" && /^\d+$/.test(candidate)) {
-    return Number(candidate);
-  }
-  return null;
-}
-
-function getErrorCode(err: unknown): string {
-  if (!err || typeof err !== "object") return "";
-  const candidate = (err as { code?: unknown }).code;
-  return typeof candidate === "string" ? candidate : "";
-}
-
-function getErrorMessage(err: unknown): string {
-  if (err instanceof Error) return err.message;
-  if (typeof err === "string") return err;
-  if (
-    typeof err === "number" ||
-    typeof err === "boolean" ||
-    typeof err === "bigint"
-  ) {
-    return String(err);
-  }
-  if (typeof err === "symbol") return err.description ?? "";
-  if (err && typeof err === "object") {
-    const message = (err as { message?: unknown }).message;
-    if (typeof message === "string") return message;
-  }
-  return "";
-}
-
-function describeFallbackError(err: unknown): {
-  message: string;
-  reason?: FailoverReason;
-  status?: number;
-  code?: string;
-} {
-  if (isFailoverError(err)) {
-    const fe = err as FailoverError;
-    return {
-      message: fe.message,
-      reason: fe.reason,
-      status: fe.status,
-      code: fe.code,
-    };
-  }
-  return {
-    message: getErrorMessage(err) || String(err),
-    status: getStatusCode(err) ?? undefined,
-    code: getErrorCode(err) || undefined,
-  };
-}
-
-function shouldFallbackForError(err: unknown): boolean {
-  if (isFailoverError(err)) return true;
-  const statusCode = getStatusCode(err);
-  if (statusCode && [401, 402, 403, 408, 429].includes(statusCode)) return true;
-  const code = getErrorCode(err).toUpperCase();
-  if (
-    ["ETIMEDOUT", "ESOCKETTIMEDOUT", "ECONNRESET", "ECONNABORTED"].includes(
-      code,
-    )
-  ) {
-    return true;
-  }
-  const message = getErrorMessage(err);
-  if (!message) return false;
-  return isFailoverErrorMessage(message);
-}
-
 function buildAllowedModelKeys(
   cfg: ClawdbotConfig | undefined,
   defaultProvider: string,
@@ -290,10 +218,15 @@ export async function runWithModelFallback<T>(params: {
       };
     } catch (err) {
       if (isAbortError(err)) throw err;
-      const shouldFallback = shouldFallbackForError(err);
-      if (!shouldFallback) throw err;
-      lastError = err;
-      const described = describeFallbackError(err);
+      const normalized =
+        coerceToFailoverError(err, {
+          provider: candidate.provider,
+          model: candidate.model,
+        }) ?? err;
+      if (!isFailoverError(normalized)) throw err;
+
+      lastError = normalized;
+      const described = describeFailoverError(normalized);
       attempts.push({
         provider: candidate.provider,
         model: candidate.model,
@@ -305,7 +238,7 @@ export async function runWithModelFallback<T>(params: {
       await params.onError?.({
         provider: candidate.provider,
         model: candidate.model,
-        error: err,
+        error: normalized,
         attempt: i + 1,
         total: candidates.length,
       });