From ff456a8b4454639209ce485e21cadd3941c4285d Mon Sep 17 00:00:00 2001
From: chenjunlong1 <chenjunlong1@wps.cn>
Date: Sat, 25 Jul 2026 10:05:56 +0800
Subject: [PATCH] fix(web): preserve streamed text spacing

---
 .changeset/fix-web-stream-text-wrapping.md    |  5 +++++
 .../src/composables/messagesToTurns.ts        |  7 ++++--
 apps/kimi-web/test/turn-logic.test.ts         | 22 +++++++++++++++++++
 3 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/fix-web-stream-text-wrapping.md

diff --git a/.changeset/fix-web-stream-text-wrapping.md b/.changeset/fix-web-stream-text-wrapping.md
new file mode 100644
index 0000000000..98ad1d194d
--- /dev/null
+++ b/.changeset/fix-web-stream-text-wrapping.md
@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+web: Fix streamed assistant text rendering with unintended line breaks between chunks.
diff --git a/apps/kimi-web/src/composables/messagesToTurns.ts b/apps/kimi-web/src/composables/messagesToTurns.ts
index 82b170a2c8..0ddc025141 100644
--- a/apps/kimi-web/src/composables/messagesToTurns.ts
+++ b/apps/kimi-web/src/composables/messagesToTurns.ts
@@ -641,8 +641,11 @@ export function messagesToTurns(
           g.textParts.push(c.text);
           // Append to a trailing text block, else open a new one — so a tool
           // call between two text segments splits them into separate blocks.
+          // Stream chunks already contain the model's whitespace (including
+          // paragraph breaks). Inserting a newline here turns token-sized
+          // chunks into one line per word, especially for Chinese output.
           const last = g.blocks.at(-1);
-          if (last && last.kind === 'text') last.text += '\n' + c.text;
+          if (last && last.kind === 'text') last.text += c.text;
           else g.blocks.push({ kind: 'text', text: c.text });
         }
       } else if (c.type === 'thinking') {
@@ -651,7 +654,7 @@ export function messagesToTurns(
           // Ordered block too: thinking renders WHERE it happened in the turn,
           // merging consecutive segments (same rule as text blocks above).
           const last = g.blocks.at(-1);
-          if (last && last.kind === 'thinking') last.thinking += '\n' + c.thinking;
+          if (last && last.kind === 'thinking') last.thinking += c.thinking;
           else g.blocks.push({ kind: 'thinking', thinking: c.thinking });
         }
       } else if (c.type === 'toolUse') {
diff --git a/apps/kimi-web/test/turn-logic.test.ts b/apps/kimi-web/test/turn-logic.test.ts
index 7c4557b4cf..732f3c3f58 100644
--- a/apps/kimi-web/test/turn-logic.test.ts
+++ b/apps/kimi-web/test/turn-logic.test.ts
@@ -102,6 +102,28 @@ describe('messagesToTurns', () => {
     expect(turns.map((turn) => turn.text)).toEqual(['one', 'two']);
   });
 
+  it('preserves whitespace when merging streamed text around empty thinking parts', () => {
+    const turns = messagesToTurns(
+      [
+        message('a1', 'assistant', [
+          { type: 'text', text: 'one' },
+          { type: 'thinking', thinking: '' },
+          { type: 'text', text: ' ' },
+          { type: 'thinking', thinking: '' },
+          { type: 'text', text: 'two' },
+          { type: 'thinking', thinking: '' },
+          { type: 'text', text: ' ' },
+          { type: 'text', text: 'three' },
+        ]),
+      ],
+      [],
+      undefined,
+      false,
+    );
+
+    expect(turns[0]?.blocks).toEqual([{ kind: 'text', text: 'one two three' }]);
+  });
+
   it('renders compaction summaries as divider turns', () => {
     const turns = messagesToTurns(
       [