fix: enhance retry logic and configuration for HTTP status codes

open-sse/config/runtimeConfig.js

@@ -45,8 +45,9 @@ export const RETRY_CONFIG = {
 // Backward compat: if value is a number, treated as attempts with RETRY_CONFIG.delayMs
 export const DEFAULT_RETRY_CONFIG = {
   429: { attempts: 0, delayMs: 0 },
-  502: { attempts: 1, delayMs: 3000 },
+  502: { attempts: 3, delayMs: 3000 },
-  503: { attempts: 1, delayMs: 2000 }
+  503: { attempts: 3, delayMs: 2000 },
+  504: { attempts: 2, delayMs: 3000 }
 };
 
 // Normalize a retry entry to { attempts, delayMs }

open-sse/executors/base.js

@@ -104,10 +104,20 @@ export class BaseExecutor {
     let lastError = null;
     let lastStatus = 0;
     const retryAttemptsByUrl = {};
-    
+
     // Merge default retry config with provider-specific config
     const retryConfig = { ...DEFAULT_RETRY_CONFIG, ...this.config.retry };
 
+    // Schedule retry via retryConfig[statusKey]. Returns true when caller should `urlIndex--; continue`
+    const tryRetry = async (urlIndex, statusKey, reason) => {
+      const { attempts, delayMs } = resolveRetryEntry(retryConfig[statusKey]);
+      if (attempts <= 0 || retryAttemptsByUrl[urlIndex] >= attempts) return false;
+      retryAttemptsByUrl[urlIndex]++;
+      log?.debug?.("RETRY", `${reason} retry ${retryAttemptsByUrl[urlIndex]}/${attempts} after ${delayMs / 1000}s`);
+      await new Promise(resolve => setTimeout(resolve, delayMs));
+      return true;
+    };
+
     for (let urlIndex = 0; urlIndex < fallbackCount; urlIndex++) {
       const url = this.buildUrl(model, stream, urlIndex, credentials);
       const transformedBody = this.transformRequest(model, body, stream, credentials);
@@ -123,15 +133,7 @@ export class BaseExecutor {
           signal
         }, proxyOptions);
 
-        // Retry based on status code config
+        if (await tryRetry(urlIndex, response.status, `status ${response.status}`)) { urlIndex--; continue; }
-        const { attempts: maxRetries, delayMs } = resolveRetryEntry(retryConfig[response.status]);
-        if (maxRetries > 0 && retryAttemptsByUrl[urlIndex] < maxRetries) {
-          retryAttemptsByUrl[urlIndex]++;
-          log?.debug?.("RETRY", `${response.status} retry ${retryAttemptsByUrl[urlIndex]}/${maxRetries} after ${delayMs / 1000}s`);
-          await new Promise(resolve => setTimeout(resolve, delayMs));
-          urlIndex--;
-          continue;
-        }
 
         if (this.shouldRetry(response.status, urlIndex)) {
           log?.debug?.("RETRY", `${response.status} on ${url}, trying fallback ${urlIndex + 1}`);
@@ -142,6 +144,11 @@ export class BaseExecutor {
         return { response, url, headers, transformedBody };
       } catch (error) {
         lastError = error;
+        if (error.name === "AbortError") throw error;
+
+        // Map network/fetch exceptions to 502 retry config
+        if (await tryRetry(urlIndex, HTTP_STATUS.BAD_GATEWAY, `network "${error.message}"`)) { urlIndex--; continue; }
+
         if (urlIndex + 1 < fallbackCount) {
           log?.debug?.("RETRY", `Error on ${url}, trying fallback ${urlIndex + 1}`);
           continue;