fix(claude): log error and mark batch failed when stop_reason is max_tokens

.changeset/lemon-impalas-yawn.md

@@ -0,0 +1,5 @@
+---
+"layne": patch
+---
+
+fix: claude prompt mode now signals an error when the API response is truncated by max_tokens instead of silently returning empty findings

src/__tests__/adapters/claude.test.ts

@@ -221,6 +221,27 @@ describe('runClaude()', () => {
     expect(findings).toEqual([]);
   });
 
+  it('logs an error when stop_reason is max_tokens instead of silently dropping findings', async () => {
+  const consoleSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
+  mockReadFile.mockResolvedValueOnce(DUMMY_CONTENT);
+  mockCreate.mockResolvedValueOnce({
+    stop_reason: 'max_tokens',
+    content: [],
+  });
+
+  await runClaude({
+    workspacePath: WORKSPACE,
+    changedFiles:  CHANGED_FILES,
+    toolConfig:    ENABLED_CONFIG,
+  });
+
+  expect(consoleSpy).toHaveBeenCalledWith(
+    expect.stringContaining('max_tokens'),
+  );
+  consoleSpy.mockRestore();
+});
+
+
   it('passes the configured model to the API', async () => {
     mockReadFile.mockResolvedValueOnce(DUMMY_CONTENT);
     mockCreate.mockResolvedValueOnce(cleanResponse());

src/adapters/claude.ts

@@ -218,6 +218,11 @@ async function scanBatchWithPrompt(
       tool_choice: { type: 'any' },
     });
 
+    if (response.stop_reason === 'max_tokens') {
+      console.error('[claude] API error during scan batch (prompt mode): response truncated — max_tokens reached, findings may be incomplete');
+      return { error: true };
+    }
+
     return extractFindings(response.content);
   } catch (err) {
     console.error('[claude] API error during scan batch (prompt mode):', (err as Error).message ?? err);