From 95503c177347a1a5e011bd0ed1c8fe830d7309b5 Mon Sep 17 00:00:00 2001
From: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>
Date: Wed, 9 Sep 2026 12:02:31 -0500
Subject: [PATCH] fix(core): send reasoning.effort for GPT-5.6+ on Bedrock
 Converse (#48195)

---
 packages/core/src/aisdk-native.ts       |  9 ++++++++-
 packages/core/test/aisdk-native.test.ts | 23 ++++++++++++++++++++---
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/packages/core/src/aisdk-native.ts b/packages/core/src/aisdk-native.ts
index 72b8d383e3d..49a398256f4 100644
--- a/packages/core/src/aisdk-native.ts
+++ b/packages/core/src/aisdk-native.ts
@@ -210,6 +210,10 @@ function mapBedrockRequest(input: MapInput): Pick<Mapping, "headers" | "body"> {
   const reasoning = isRecord(settings.reasoningConfig) ? settings.reasoningConfig : undefined
   const anthropic = input.modelID.includes("anthropic")
   const openai = input.modelID.includes("openai.")
+  // Converse passes OpenAI fields through verbatim. gpt-oss (Harmony) takes the
+  // flat chat-completions `reasoning_effort`; GPT-5.6+ reject it and take the
+  // Responses-style `reasoning.effort` instead.
+  const harmony = input.modelID.includes("openai.gpt-oss")
   const effort = typeof reasoning?.maxReasoningEffort === "string" ? reasoning.maxReasoningEffort : undefined
   const type = typeof reasoning?.type === "string" ? reasoning.type : undefined
   const budget = typeof reasoning?.budgetTokens === "number" ? reasoning.budgetTokens : undefined
@@ -236,7 +240,10 @@ function mapBedrockRequest(input: MapInput): Pick<Mapping, "headers" | "body"> {
           },
         }
       : {}),
-    ...(!anthropic && openai && effort !== undefined ? { reasoning_effort: effort } : {}),
+    ...(!anthropic && openai && harmony && effort !== undefined ? { reasoning_effort: effort } : {}),
+    ...(!anthropic && openai && !harmony && effort !== undefined
+      ? { reasoning: { ...(isRecord(additional.reasoning) ? additional.reasoning : {}), effort } }
+      : {}),
     ...(!anthropic && !openai && effort !== undefined
       ? {
           reasoningConfig: {
diff --git a/packages/core/test/aisdk-native.test.ts b/packages/core/test/aisdk-native.test.ts
index 4a9ff46ef0c..bf43bbc4d66 100644
--- a/packages/core/test/aisdk-native.test.ts
+++ b/packages/core/test/aisdk-native.test.ts
@@ -251,11 +251,28 @@ describe("AISDKNative", () => {
       },
     })
 
-    for (const modelID of ["openai.gpt-oss-120b-1:0", "global.openai.gpt-5.6-sol", "us.openai.gpt-5.6-sol"]) {
+    // gpt-oss (Harmony) keeps the flat chat-completions field.
+    expect(
+      map("@ai-sdk/amazon-bedrock", { reasoningConfig: { maxReasoningEffort: "high" } }, "openai.gpt-oss-120b-1:0")
+        ?.body,
+    ).toEqual({ additionalModelRequestFields: { reasoning_effort: "high" } })
+
+    // GPT-5.6+ reject `reasoning_effort` and take the Responses-style nested field.
+    for (const modelID of ["global.openai.gpt-5.6-sol", "us.openai.gpt-5.6-sol", "us.openai.gpt-6-astra"]) {
       expect(
-        map("@ai-sdk/amazon-bedrock", { reasoningConfig: { maxReasoningEffort: "high" } }, modelID)?.body,
-      ).toEqual({ additionalModelRequestFields: { reasoning_effort: "high" } })
+        map("@ai-sdk/amazon-bedrock", { reasoningConfig: { maxReasoningEffort: "none" } }, modelID)?.body,
+      ).toEqual({ additionalModelRequestFields: { reasoning: { effort: "none" } } })
     }
+    expect(
+      map(
+        "@ai-sdk/amazon-bedrock",
+        {
+          reasoningConfig: { maxReasoningEffort: "high" },
+          additionalModelRequestFields: { reasoning: { summary: "auto" } },
+        },
+        "us.openai.gpt-5.6-sol",
+      )?.body,
+    ).toEqual({ additionalModelRequestFields: { reasoning: { summary: "auto", effort: "high" } } })
   })
 
   test("maps Bedrock Mantle models to their supported native APIs", () => {