diff --git a/packages/ai/CHANGELOG.md b/packages/ai/CHANGELOG.md
index 2349b3f7..2e827d25 100644
--- a/packages/ai/CHANGELOG.md
+++ b/packages/ai/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+- Added `serviceTier` option for OpenAI Responses requests ([#672](https://github.com/badlogic/pi-mono/pull/672) by [@markusylisiurunen](https://github.com/markusylisiurunen))
+
 ## [0.44.0] - 2026-01-12
 
 ## [0.43.0] - 2026-01-11
diff --git a/packages/ai/src/providers/openai-responses.ts b/packages/ai/src/providers/openai-responses.ts
index c10dd68e..3719ecad 100644
--- a/packages/ai/src/providers/openai-responses.ts
+++ b/packages/ai/src/providers/openai-responses.ts
@@ -48,6 +48,7 @@ function shortHash(str: string): string {
 export interface OpenAIResponsesOptions extends StreamOptions {
 	reasoningEffort?: "minimal" | "low" | "medium" | "high" | "xhigh";
 	reasoningSummary?: "auto" | "detailed" | "concise" | null;
+	serviceTier?: ResponseCreateParamsStreaming["service_tier"];
 }
 
 /**
@@ -373,6 +374,10 @@ function buildParams(model: Model<"openai-responses">, context: Context, options
 		params.temperature = options?.temperature;
 	}
 
+	if (options?.serviceTier !== undefined) {
+		params.service_tier = options.serviceTier;
+	}
+
 	if (context.tools) {
 		params.tools = convertTools(context.tools);
 	}