fix(server): log each provider fallback during metadata generation

packages/server/src/server/agent/agent-metadata-generator.ts

@@ -132,25 +132,19 @@ export async function generateAndApplyAgentMetadata(
       maxRetries: 2,
       providers: DEFAULT_STRUCTURED_GENERATION_PROVIDERS,
       persistSession: false,
+      logger: options.logger,
       agentConfigOverrides: {
         title: "Agent metadata generator",
         internal: true,
       },
     });
   } catch (error) {
-    if (
-      error instanceof StructuredAgentResponseError ||
-      error instanceof StructuredAgentFallbackError
-    ) {
-      options.logger.warn(
-        { err: error, agentId: options.agentId },
-        "Structured metadata generation failed",
-      );
-      return;
-    }
+    const attempts = error instanceof StructuredAgentFallbackError ? error.attempts : undefined;
     options.logger.error(
-      { err: error, agentId: options.agentId },
-      "Agent metadata generation failed",
+      { err: error, agentId: options.agentId, attempts },
+      error instanceof StructuredAgentResponseError || error instanceof StructuredAgentFallbackError
+        ? "Structured metadata generation failed"
+        : "Agent metadata generation failed",
     );
     return;
   }

packages/server/src/server/agent/agent-response-loop.ts

@@ -5,6 +5,11 @@ import type { AgentProvider, AgentSessionConfig } from "./agent-sdk-types.js";
 import type { AgentManager } from "./agent-manager.js";
 import { getAgentProviderDefinition } from "./provider-manifest.js";
 
+export interface StructuredGenerationLogger {
+  info: (obj: object, msg?: string) => void;
+  warn: (obj: object, msg?: string) => void;
+}
+
 export type JsonSchema = Record<string, unknown>;
 
 export type AgentCaller = (prompt: string) => Promise<string>;
@@ -90,6 +95,7 @@ export interface StructuredAgentGenerationWithFallbackOptions<T> {
   persistSession?: boolean;
   maxRetries?: number;
   schemaName?: string;
+  logger?: StructuredGenerationLogger;
   runner?: <TResult>(options: StructuredAgentGenerationOptions<TResult>) => Promise<TResult>;
 }
 
@@ -397,6 +403,7 @@ export async function generateStructuredAgentResponseWithFallback<T>(
     persistSession,
     maxRetries,
     schemaName,
+    logger,
     runner,
   } = options;
 
@@ -414,12 +421,17 @@ export async function generateStructuredAgentResponseWithFallback<T>(
   for (const candidate of providers) {
     const availabilityEntry = availabilityByProvider.get(candidate.provider);
     if (availabilityEntry && !availabilityEntry.available) {
+      const reason = availabilityEntry.error ?? "unavailable";
       attempts.push({
         provider: candidate.provider,
         model: candidate.model ?? null,
         available: false,
         error: availabilityEntry.error ?? null,
       });
+      logger?.warn(
+        { provider: candidate.provider, model: candidate.model, schemaName, reason },
+        "Structured generation: skipping unavailable provider",
+      );
       continue;
     }
 
@@ -439,6 +451,17 @@ export async function generateStructuredAgentResponseWithFallback<T>(
           ...(candidate.thinkingOptionId ? { thinkingOptionId: candidate.thinkingOptionId } : {}),
         },
       });
+      if (attempts.length > 0) {
+        logger?.info(
+          {
+            provider: candidate.provider,
+            model: candidate.model,
+            schemaName,
+            priorAttempts: attempts,
+          },
+          "Structured generation: succeeded after fallback",
+        );
+      }
       return result;
     } catch (error) {
       attempts.push({
@@ -447,6 +470,10 @@ export async function generateStructuredAgentResponseWithFallback<T>(
         available: true,
         error: errorMessage(error),
       });
+      logger?.warn(
+        { err: error, provider: candidate.provider, model: candidate.model, schemaName },
+        "Structured generation: provider failed, trying next",
+      );
     }
   }
 

packages/server/src/server/worktree-branch-name-generator.ts

@@ -12,6 +12,7 @@ import { buildMetadataPrompt } from "../utils/build-metadata-prompt.js";
 import type { WorkspaceGitService } from "./workspace-git-service.js";
 
 interface BranchNameGeneratorLogger {
+  info: (obj: object, msg?: string) => void;
   warn: (obj: object, msg?: string) => void;
   error: (obj: object, msg?: string) => void;
 }
@@ -77,6 +78,7 @@ export async function generateBranchNameFromFirstAgentContext(
       maxRetries: 2,
       providers: DEFAULT_STRUCTURED_GENERATION_PROVIDERS,
       persistSession: false,
+      logger: options.logger,
       agentConfigOverrides: {
         title: "Branch name generator",
         internal: true,
@@ -84,14 +86,13 @@ export async function generateBranchNameFromFirstAgentContext(
     });
     return result.branch.trim() || null;
   } catch (error) {
-    if (
-      error instanceof StructuredAgentResponseError ||
-      error instanceof StructuredAgentFallbackError
-    ) {
-      options.logger.warn({ err: error }, "Structured branch name generation failed");
-      return null;
-    }
-    options.logger.error({ err: error }, "Branch name generation failed");
+    const attempts = error instanceof StructuredAgentFallbackError ? error.attempts : undefined;
+    options.logger.error(
+      { err: error, attempts },
+      error instanceof StructuredAgentResponseError || error instanceof StructuredAgentFallbackError
+        ? "Structured branch name generation failed"
+        : "Branch name generation failed",
+    );
     return null;
   }
 }