feat(open-sse): non-streaming stream-error pattern match → 502 fallback

open-sse/handlers/chatCore/sseToJsonHandler.js

@@ -1,4 +1,5 @@
 import { convertResponsesStreamToJson } from "../../transformer/streamToJsonConverter.js";
+import { matchStreamErrorPatterns } from "../../utils/streamErrorPatterns.js";
 import { createErrorResult } from "../../utils/error.js";
 import { HTTP_STATUS } from "../../config/runtimeConfig.js";
 import { FORMATS } from "../../translator/formats.js";
@@ -108,7 +109,7 @@ export function parseSSEToOpenAIResponse(rawSSE, fallbackModel) {
  * Handle case: provider forced streaming but client wants JSON.
  * Supports both Codex/Responses API SSE and standard Chat Completions SSE.
  */
-export async function handleForcedSSEToJson({ providerResponse, sourceFormat, provider, model, body, stream, translatedBody, finalBody, requestStartTime, connectionId, apiKey, clientRawRequest, onRequestSuccess, trackDone, appendLog, reqTag, log }) {
+export async function handleForcedSSEToJson({ providerResponse, sourceFormat, provider, model, body, stream, translatedBody, finalBody, requestStartTime, connectionId, apiKey, clientRawRequest, onRequestSuccess, trackDone, appendLog, reqTag, log, streamErrorPatterns }) {
   const contentType = providerResponse.headers.get("content-type") || "";
   const isSSE = contentType.includes("text/event-stream") || (contentType === "" && isResponsesProvider(provider));
   if (!isSSE) return null; // not handled here
@@ -209,6 +210,17 @@ export async function handleForcedSSEToJson({ providerResponse, sourceFormat, pr
       );
     }
 
+    // Config-driven in-stream error detection: the request "succeeded" at the
+    // HTTP level, but the content signals an upstream failure — treat it as an
+    // error so account/combo fallback and FAILED logging kick in.
+    const matchedPattern = matchStreamErrorPatterns(
+      streamErrorPatterns?.[provider],
+      parsed.choices?.[0]?.message?.content || ""
+    );
+    if (matchedPattern) {
+      return createErrorResult(HTTP_STATUS.BAD_GATEWAY, `Stream error pattern matched: ${matchedPattern}`);
+    }
+
     if (onRequestSuccess) await onRequestSuccess();
 
     const usage = parsed.usage || {};