From fdaeccf1e52ed36361331aa55260506b4719efef Mon Sep 17 00:00:00 2001
From: AveryanAlex <alex@averyan.ru>
Date: Sun, 29 Mar 2026 00:26:24 +0300
Subject: [PATCH] fix: use replaceAll for think tags to handle multiple
 occurrences

---
 open-sse/transformer/responsesTransformer.ts    |  2 +-
 .../translator/response/openai-responses.ts     |  2 +-
 tests/unit/responses-translation-fixes.test.mjs | 17 +++++++++++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/open-sse/transformer/responsesTransformer.ts b/open-sse/transformer/responsesTransformer.ts
index 602adcdd1c..6a6f8540ca 100644
--- a/open-sse/transformer/responsesTransformer.ts
+++ b/open-sse/transformer/responsesTransformer.ts
@@ -377,7 +377,7 @@ export function createResponsesApiTransformStream(logger = null) {
 
           if (content.includes("<think>")) {
             state.inThinking = true;
-            content = content.replace("<think>", "");
+            content = content.replaceAll("<think>", "");
             startReasoning(controller, idx);
           }
 
diff --git a/open-sse/translator/response/openai-responses.ts b/open-sse/translator/response/openai-responses.ts
index 745b643de8..40ec923bd4 100644
--- a/open-sse/translator/response/openai-responses.ts
+++ b/open-sse/translator/response/openai-responses.ts
@@ -75,7 +75,7 @@ export function openaiToOpenAIResponsesResponse(chunk, state) {
 
     if (content.includes("<think>")) {
       state.inThinking = true;
-      content = content.replace("<think>", "");
+      content = content.replaceAll("<think>", "");
       startReasoning(state, emit, idx);
     }
 
diff --git a/tests/unit/responses-translation-fixes.test.mjs b/tests/unit/responses-translation-fixes.test.mjs
index 8ecf34f4bd..6d66f7ed73 100644
--- a/tests/unit/responses-translation-fixes.test.mjs
+++ b/tests/unit/responses-translation-fixes.test.mjs
@@ -403,3 +403,20 @@ test("Responses→Chat streaming: reasoning delta emits reasoning_content in Cha
   assert.ok(result, "should return a chunk");
   assert.equal(result.choices[0].delta.reasoning_content, "thinking step...");
 });
+
+test("Chat→Responses streaming: multiple <think> tags in one chunk handled", () => {
+  const state = initState(FORMATS.OPENAI_RESPONSES);
+
+  // Chunk with multiple think tags
+  const chunk = {
+    choices: [{ index: 0, delta: { content: "<think>first</think>middle<think>second</think>end" }, finish_reason: null }],
+    id: "c1",
+  };
+  const events = openaiToOpenAIResponsesResponse(chunk, state);
+  // Should not have literal <think> in any text delta
+  const textDeltas = events
+    .filter((e) => e.event === "response.output_text.delta")
+    .map((e) => e.data.delta);
+  const combined = textDeltas.join("");
+  assert.ok(!combined.includes("<think>"), `text should not contain <think> tag, got: ${combined}`);
+});