Agents: classify Anthropic api_error internal server failures for fallback

CHANGELOG.md

@@ -21,6 +21,7 @@ Docs: https://docs.openclaw.ai
 - Cron/Gateway: keep `cron.list` and `cron.status` responsive during startup catch-up by avoiding a long-held cron lock while missed jobs execute. (#23106) Thanks @jayleekr.
 - Gateway/Config reload: compare array-valued config paths structurally during diffing so unchanged `memory.qmd.paths` and `memory.qmd.scope.rules` no longer trigger false restart-required reloads. (#23185) Thanks @rex05ai.
 - TUI/Input: enable multiline-paste burst coalescing on macOS Terminal.app and iTerm so pasted blocks no longer submit line-by-line as separate messages. (#18809) Thanks @fwends.
+- Agents/Fallbacks: treat JSON payloads with `type: "api_error"` + `"Internal server error"` as transient failover errors so Anthropic 500-style failures trigger model fallback. (#23193) Thanks @jarvis-lane.
 - Gateway/Pairing: treat operator.admin pairing tokens as satisfying operator.write requests so legacy devices stop looping through scope-upgrade prompts introduced in 2026.2.19. (#23125, #23006) Thanks @vignesh07.
 - Memory/QMD: add optional `memory.qmd.mcporter` search routing so QMD `query/search/vsearch` can run through mcporter keep-alive flows (including multi-collection paths) to reduce cold starts, while keeping searches on agent-scoped QMD state for consistent recall. (#19617) Thanks @nicole-luxe and @vignesh07.
 - Chat/UI: strip inline reply/audio directive tags (`[[reply_to_current]]`, `[[reply_to:<id>]]`, `[[audio_as_voice]]`) from displayed chat history, live chat event output, and session preview snippets so control tags no longer leak into user-visible surfaces.

src/agents/pi-embedded-helpers.isbillingerrormessage.e2e.test.ts

@@ -377,4 +377,11 @@ describe("classifyFailoverReason", () => {
       ),
     ).toBe("rate_limit");
   });
+  it("classifies JSON api_error internal server failures as timeout", () => {
+    expect(
+      classifyFailoverReason(
+        '{"type":"error","error":{"type":"api_error","message":"Internal server error"}}',
+      ),
+    ).toBe("timeout");
+  });
 });

src/agents/pi-embedded-helpers/errors.ts

@@ -686,6 +686,16 @@ export function isOverloadedErrorMessage(raw: string): boolean {
   return matchesErrorPatterns(raw, ERROR_PATTERNS.overloaded);
 }
 
+function isJsonApiInternalServerError(raw: string): boolean {
+  if (!raw) {
+    return false;
+  }
+  const value = raw.toLowerCase();
+  // Anthropic often wraps transient 500s in JSON payloads like:
+  // {"type":"error","error":{"type":"api_error","message":"Internal server error"}}
+  return value.includes('"type":"api_error"') && value.includes("internal server error");
+}
+
 export function parseImageDimensionError(raw: string): {
   maxDimensionPx?: number;
   messageIndex?: number;
@@ -794,6 +804,9 @@ export function classifyFailoverReason(raw: string): FailoverReason | null {
     // Treat transient 5xx provider failures as retryable transport issues.
     return "timeout";
   }
+  if (isJsonApiInternalServerError(raw)) {
+    return "timeout";
+  }
   if (isRateLimitErrorMessage(raw)) {
     return "rate_limit";
   }