From a2ceadcc2acb8c47acd63293ff94a22bf4237f81 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sun, 15 Feb 2026 19:08:47 +0000
Subject: [PATCH] refactor(gateway): dedupe assistant delta parsing

---
 src/gateway/agent-event-assistant-text.ts | 7 +++++++
 src/gateway/openai-http.ts                | 5 ++---
 src/gateway/openresponses-http.ts         | 5 ++---
 3 files changed, 11 insertions(+), 6 deletions(-)
 create mode 100644 src/gateway/agent-event-assistant-text.ts

diff --git a/src/gateway/agent-event-assistant-text.ts b/src/gateway/agent-event-assistant-text.ts
new file mode 100644
index 0000000000..6341664d7d
--- /dev/null
+++ b/src/gateway/agent-event-assistant-text.ts
@@ -0,0 +1,7 @@
+import type { AgentEventPayload } from "../infra/agent-events.js";
+
+export function resolveAssistantStreamDeltaText(evt: AgentEventPayload): string {
+  const delta = evt.data.delta;
+  const text = evt.data.text;
+  return typeof delta === "string" ? delta : typeof text === "string" ? text : "";
+}
diff --git a/src/gateway/openai-http.ts b/src/gateway/openai-http.ts
index 038dc3540d..12d80cdfac 100644
--- a/src/gateway/openai-http.ts
+++ b/src/gateway/openai-http.ts
@@ -7,6 +7,7 @@ import { agentCommand } from "../commands/agent.js";
 import { emitAgentEvent, onAgentEvent } from "../infra/agent-events.js";
 import { logWarn } from "../logger.js";
 import { defaultRuntime } from "../runtime.js";
+import { resolveAssistantStreamDeltaText } from "./agent-event-assistant-text.js";
 import {
   buildAgentMessageFromConversationEntries,
   type ConversationEntry,
@@ -243,9 +244,7 @@ export async function handleOpenAiHttpRequest(
     }
 
     if (evt.stream === "assistant") {
-      const delta = evt.data?.delta;
-      const text = evt.data?.text;
-      const content = typeof delta === "string" ? delta : typeof text === "string" ? text : "";
+      const content = resolveAssistantStreamDeltaText(evt);
       if (!content) {
         return;
       }
diff --git a/src/gateway/openresponses-http.ts b/src/gateway/openresponses-http.ts
index 896ae9b184..0ce1189d5c 100644
--- a/src/gateway/openresponses-http.ts
+++ b/src/gateway/openresponses-http.ts
@@ -36,6 +36,7 @@ import {
   type InputImageSource,
 } from "../media/input-files.js";
 import { defaultRuntime } from "../runtime.js";
+import { resolveAssistantStreamDeltaText } from "./agent-event-assistant-text.js";
 import {
   buildAgentMessageFromConversationEntries,
   type ConversationEntry,
@@ -727,9 +728,7 @@ export async function handleOpenResponsesHttpRequest(
     }
 
     if (evt.stream === "assistant") {
-      const delta = evt.data?.delta;
-      const text = evt.data?.text;
-      const content = typeof delta === "string" ? delta : typeof text === "string" ? text : "";
+      const content = resolveAssistantStreamDeltaText(evt);
       if (!content) {
         return;
       }