fix(responses): drop the internal summary:none marker before it reaches the upstream

src/adapters/openai-responses/passthrough.ts

@@ -34,7 +34,7 @@ import {
 import {
   createAdapterTierMetadata,
 } from "../../providers/fastwire";
-import { dropResponsesReasoningInputItems, mapRoutedResponsesReasoningEffort, normalizeConfiguredReasoningSummaryDelivery, sanitizeReasoningInputContent, stripDisabledReasoningSummaries, stripDisabledVerbosity, stripUnsupportedReasoningSummaryDelivery } from "./reasoning";
+import { dropResponsesReasoningInputItems, mapRoutedResponsesReasoningEffort, normalizeConfiguredReasoningSummaryDelivery, sanitizeReasoningInputContent, stripDisabledReasoningSummaries, stripDisabledVerbosity, stripNoneReasoningSummary, stripUnsupportedReasoningSummaryDelivery } from "./reasoning";
 import { scrubOcxCompactionItems, stripCanonicalOnlyToolFields, stripCanonicalOnlyTopLevelFields, stripInternalChatMessageMetadataPassthrough, stripInvalidItemIds, stripItemIdsWhenUnstored, stripRejectedSamplingParams } from "./request-strips";
 import { stripCanonicalForwardPromptCacheOptions, stripDeprecatedPromptCacheRetention } from "./prompt-cache";
 import { isPlainObject } from "./internal";
@@ -352,6 +352,7 @@ export function createResponsesPassthroughAdapter(provider: OcxProviderConfig):
         outBody = repairOversizedReplayCallIds(outBody);
       }
       outBody = stripUnsupportedReasoningSummaryDelivery(outBody, parsed.modelId);
+      outBody = stripNoneReasoningSummary(outBody);
       // #4587: on a bridged provider, hand the destination back the search call and result the
       // proxy executed on its behalf, in place of the hosted cell the caller replays. Scoped to
       // its exact conversation and serving identity and recorded by the bridge itself, so a

src/adapters/openai-responses/reasoning.ts

@@ -156,6 +156,21 @@ export function sanitizeReasoningInputContent(
   return changed ? { ...raw, input } : body;
 }
 
+/**
+ * `reasoning.summary: "none"` is an internal "hide the thinking summary" marker: Claude's
+ * `thinking.display: "omitted"` maps to it, and the parser reads it into
+ * `options.hideThinkingSummary`. It is not a Responses API value (valid: auto, concise,
+ * detailed), so drop it from the body that is serialized to the upstream.
+ */
+export function stripNoneReasoningSummary(body: unknown): unknown {
+  if (!isPlainObject(body) || !isPlainObject(body.reasoning) || body.reasoning.summary !== "none") return body;
+  const { summary: _summary, ...rest } = body.reasoning;
+  const next = { ...body };
+  if (Object.keys(rest).length > 0) next.reasoning = rest;
+  else delete next.reasoning;
+  return next;
+}
+
 export function stripUnsupportedReasoningSummaryDelivery(body: unknown, modelId: string): unknown {
   if (catalogModelSupportsReasoningSummaries(modelId) !== false) return body;
   if (!isPlainObject(body) || !isPlainObject(body.stream_options)) return body;

tests/responses/openai-responses-passthrough.test.ts

@@ -1825,6 +1825,34 @@ describe("OpenAI Responses passthrough sanitization", () => {
     expect(body.reasoning).toEqual({ effort: "high" });
   });
 
+  test("Claude omitted thinking display never puts summary:none on the Responses wire", () => {
+    const claudeBody = anthropicToResponsesBody({
+      model: "gpt-6-astra",
+      max_tokens: 10,
+      messages: [{ role: "user", content: "hi" }],
+      thinking: { type: "adaptive", display: "omitted" },
+      output_config: { effort: "high" },
+    });
+    // The translator still emits the marker, so the parser can hide the thinking summary.
+    expect((claudeBody as { reasoning?: unknown }).reasoning).toEqual({ summary: "none", effort: "high" });
+
+    for (const target of [
+      { ...provider, baseUrl: "https://chatgpt.com/backend-api/codex", authMode: "forward" as const },
+      { adapter: "openai-responses", baseUrl: "https://api.openai.com/v1", authMode: "key" as const, apiKey: "sk-test" },
+    ]) {
+      const parsed = parseRequest(claudeBody);
+      expect(parsed.options.hideThinkingSummary).toBe(true);
+      const request = createResponsesPassthroughAdapter(target).buildRequest(parsed, { headers: new Headers() });
+      const wire = JSON.parse(request.body) as { reasoning?: Record<string, unknown> };
+      expect(wire.reasoning).toEqual({ effort: "high" });
+    }
+
+    // A summary-only marker leaves no empty reasoning object behind.
+    const summaryOnly = parseRequest({ model: "gpt-6-astra", input: "hi", reasoning: { summary: "none" } });
+    const wire = JSON.parse(createResponsesPassthroughAdapter(provider).buildRequest(summaryOnly, { headers: new Headers() }).body);
+    expect(wire.reasoning).toBeUndefined();
+  });
+
   function routedXaiResponsesProvider() {
     const entry = getProviderRegistryEntry("xai")!;
     const route = routeModel({