diff --git a/packages/ai/src/providers/amazon-bedrock.ts b/packages/ai/src/providers/amazon-bedrock.ts
index a2743647..d58ec3aa 100644
--- a/packages/ai/src/providers/amazon-bedrock.ts
+++ b/packages/ai/src/providers/amazon-bedrock.ts
@@ -200,6 +200,14 @@ export const streamSimpleBedrock: StreamFunction<"bedrock-converse-stream", Simp
 	}
 
 	if (model.id.includes("anthropic.claude") || model.id.includes("anthropic/claude")) {
+		if (supportsAdaptiveThinking(model.id)) {
+			return streamBedrock(model, context, {
+				...base,
+				reasoning: options.reasoning,
+				thinkingBudgets: options.thinkingBudgets,
+			} satisfies BedrockOptions);
+		}
+
 		const adjusted = adjustMaxTokensForThinking(
 			base.maxTokens || 0,
 			model.maxTokens,
@@ -347,6 +355,29 @@ function handleContentBlockStop(
 	}
 }
 
+/**
+ * Check if the model supports adaptive thinking (Opus 4.6+).
+ */
+function supportsAdaptiveThinking(modelId: string): boolean {
+	return modelId.includes("opus-4-6") || modelId.includes("opus-4.6");
+}
+
+function mapThinkingLevelToEffort(level: SimpleStreamOptions["reasoning"]): "low" | "medium" | "high" | "max" {
+	switch (level) {
+		case "minimal":
+		case "low":
+			return "low";
+		case "medium":
+			return "medium";
+		case "high":
+			return "high";
+		case "xhigh":
+			return "max";
+		default:
+			return "high";
+	}
+}
+
 /**
  * Check if the model supports prompt caching.
  * Supported: Claude 3.5 Haiku, Claude 3.7 Sonnet, Claude 4.x models
@@ -589,26 +620,33 @@ function buildAdditionalModelRequestFields(
 	}
 
 	if (model.id.includes("anthropic.claude")) {
-		const defaultBudgets: Record<ThinkingLevel, number> = {
-			minimal: 1024,
-			low: 2048,
-			medium: 8192,
-			high: 16384,
-			xhigh: 16384, // Claude doesn't support xhigh, clamp to high
-		};
+		const result: Record<string, any> = supportsAdaptiveThinking(model.id)
+			? {
+					thinking: { type: "adaptive" },
+					output_config: { effort: mapThinkingLevelToEffort(options.reasoning) },
+				}
+			: (() => {
+					const defaultBudgets: Record<ThinkingLevel, number> = {
+						minimal: 1024,
+						low: 2048,
+						medium: 8192,
+						high: 16384,
+						xhigh: 16384, // Claude doesn't support xhigh, clamp to high
+					};
 
-		// Custom budgets override defaults (xhigh not in ThinkingBudgets, use high)
-		const level = options.reasoning === "xhigh" ? "high" : options.reasoning;
-		const budget = options.thinkingBudgets?.[level] ?? defaultBudgets[options.reasoning];
+					// Custom budgets override defaults (xhigh not in ThinkingBudgets, use high)
+					const level = options.reasoning === "xhigh" ? "high" : options.reasoning;
+					const budget = options.thinkingBudgets?.[level] ?? defaultBudgets[options.reasoning];
 
-		const result: Record<string, any> = {
-			thinking: {
-				type: "enabled",
-				budget_tokens: budget,
-			},
-		};
+					return {
+						thinking: {
+							type: "enabled",
+							budget_tokens: budget,
+						},
+					};
+				})();
 
-		if (options.interleavedThinking) {
+		if (options.interleavedThinking && !supportsAdaptiveThinking(model.id)) {
 			result.anthropic_beta = ["interleaved-thinking-2025-05-14"];
 		}
 
diff --git a/packages/ai/test/stream.test.ts b/packages/ai/test/stream.test.ts
index 6d86b40f..f1fa20ca 100644
--- a/packages/ai/test/stream.test.ts
+++ b/packages/ai/test/stream.test.ts
@@ -1190,6 +1190,50 @@ describe("Generate E2E Tests", () => {
 		});
 	});
 
+	describe.skipIf(!hasBedrockCredentials())("Amazon Bedrock Provider (claude-opus-4-6 interleaved thinking)", () => {
+		const llm = getModel("amazon-bedrock", "global.anthropic.claude-opus-4-6-v1");
+
+		it("should use adaptive thinking without anthropic_beta", { retry: 3 }, async () => {
+			let capturedPayload: unknown;
+			const response = await complete(
+				llm,
+				{
+					systemPrompt: "You are a helpful assistant that uses tools when asked.",
+					messages: [
+						{
+							role: "user",
+							content: "Think first, then calculate 15 + 27 using the calculator tool.",
+							timestamp: Date.now(),
+						},
+					],
+					tools: [calculatorTool],
+				},
+				{
+					reasoning: "xhigh",
+					interleavedThinking: true,
+					onPayload: (payload) => {
+						capturedPayload = payload;
+					},
+				},
+			);
+
+			expect(response.stopReason, `Error: ${response.errorMessage}`).not.toBe("error");
+			expect(capturedPayload).toBeTruthy();
+
+			const payload = capturedPayload as {
+				additionalModelRequestFields?: {
+					thinking?: { type?: string };
+					output_config?: { effort?: string };
+					anthropic_beta?: string[];
+				};
+			};
+
+			expect(payload.additionalModelRequestFields?.thinking).toEqual({ type: "adaptive" });
+			expect(payload.additionalModelRequestFields?.output_config).toEqual({ effort: "max" });
+			expect(payload.additionalModelRequestFields?.anthropic_beta).toBeUndefined();
+		});
+	});
+
 	// Check if ollama is installed and local LLM tests are enabled
 	let ollamaInstalled = false;
 	if (!process.env.PI_NO_LOCAL_LLM) {