fix(translator): thread model through normalizeResponsesReasoningEffort in promotion path (#8997)

Closes #8997
Refs: base-red #9737
fix/8997-gpt56-max-reasoning-rewritte

changelog.d/fixes/8997-gpt56-max-reasoning.plan.md

@@ -0,0 +1 @@
+- **fix(translator):** the Responses-to-Chat promotion path called `normalizeResponsesReasoningEffort` without the model argument, so GPT-5.6 Sol/Terra/Luna requests with `reasoning.effort: "max""` were downgraded to `"xhigh"`. The model is now threaded through, preserving `max` for GPT-5.6 while keeping the legacy downgrade for older models ([#8997](https://github.com/diegosouzapw/OmniRoute/pull/8997))

open-sse/translator/request/openai-responses.ts

@@ -724,7 +724,7 @@ export function openaiResponsesToOpenAIRequest(
     const reasoningRec = toRecord(root.reasoning);
     const effort = toString(reasoningRec.effort);
     if (effort && result.reasoning_effort === undefined) {
-      result.reasoning_effort = normalizeResponsesReasoningEffort(effort, model);
+      result.reasoning_effort = normalizeResponsesReasoningEffort(effort, model ?? root.model);
     }
     if (
       credentialRecord._copilotClient === true &&

tests/unit/triage-bugs-2026-08-02.test.ts

@@ -117,4 +117,50 @@ test("#8853 proxyConfigToUrl accepts ProxyRegistryRecord-shaped object", () => {
 test("#8853 proxyConfigToUrl returns null for partial config (no host)", () => {
   const url = proxyConfigToUrl({ type: "http", port: 8080 } as Record<string, unknown>);
   assert.equal(url, null, "proxyConfigToUrl must return null for partial config without host");
+});
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import { openaiResponsesToOpenAIRequest } from "../../open-sse/translator/request/openai-responses.ts";
+
+function asRecord(value: unknown): Record<string, unknown> {
+  return value as Record<string, unknown>;
+}
+
+for (const variant of ["gpt-5.6-sol", "gpt-5.6-terra", "gpt-5.6-luna"]) {
+  test(`#8997 ${variant} nested reasoning.effort max survives promotion`, () => {
+    const translated = asRecord(
+      openaiResponsesToOpenAIRequest(
+        variant,
+        { model: variant, input: "hello", reasoning: { effort: "max" } },
+        false,
+        {}
+      )
+    );
+    assert.equal(translated.reasoning_effort, "max");
+  });
+
+  test(`#8997 ${variant} flat reasoning_effort max survives promotion`, () => {
+    const translated = asRecord(
+      openaiResponsesToOpenAIRequest(
+        variant,
+        { model: variant, input: "hello", reasoning_effort: "max" },
+        false,
+        {}
+      )
+    );
+    assert.equal(translated.reasoning_effort, "max");
+  });
+}
+
+test("non-GPT-5.6 models still get max downgraded to xhigh", () => {
+  const translated = asRecord(
+    openaiResponsesToOpenAIRequest(
+      "gpt-4o",
+      { model: "gpt-4o", input: "hello", reasoning: { effort: "max" } },
+      false,
+      {}
+    )
+  );
+  assert.equal(translated.reasoning_effort, "xhigh");
 });