From 70f264b19976f659794793402673a45bc2cc7a47 Mon Sep 17 00:00:00 2001
From: DIodide <ibraheem.amin3@gmail.com>
Date: Sat, 22 Aug 2026 14:19:18 -0400
Subject: [PATCH] Stitch recovery-split text parts back together; add
 stream-stall watchdog
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A stream interruption mid-turn makes Think persist the partial and
append the continuation as a NEW text part — often mid-sentence. The
chat renderer treated each text part as a standalone markdown document,
tearing sentences and lists apart at the seam ("Get a major" / "'s full
requirement tree…"). Consecutive text parts are now concatenated before
rendering.

Also sets chatStreamStallTimeoutMs = 120s so a model stream that parks
without erroring gets aborted into Think's bounded recovery path
instead of leaving the client spinning — the likely source of the
"spotty" feel.

Claude-Session: https://claude.ai/code/session_01MKLJUWk6biNAKXupHTTWn5
---
 app/src/client/pages/ChatPage.tsx | 21 ++++++++++++++++++++-
 app/src/server/pi.ts              |  6 ++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/app/src/client/pages/ChatPage.tsx b/app/src/client/pages/ChatPage.tsx
index edf9a37..b4dcc40 100644
--- a/app/src/client/pages/ChatPage.tsx
+++ b/app/src/client/pages/ChatPage.tsx
@@ -18,6 +18,25 @@ const SUGGESTIONS = [
   "Does anything in my schedule conflict?",
 ];
 
+/**
+ * A stream interruption + recovery can split one utterance across several
+ * consecutive text parts (often mid-sentence). Rendering each part as its
+ * own markdown block tears sentences and lists apart, so stitch runs of
+ * text parts back together before rendering.
+ */
+function coalesceParts(parts: UIMessage["parts"]): UIMessage["parts"] {
+  const out: UIMessage["parts"] = [];
+  for (const part of parts) {
+    const last = out[out.length - 1];
+    if (part.type === "text" && last?.type === "text") {
+      out[out.length - 1] = { ...last, text: last.text + part.text };
+    } else {
+      out.push(part);
+    }
+  }
+  return out;
+}
+
 function messageText(m: UIMessage): string {
   return m.parts
     .map((p) => (p.type === "text" ? p.text : ""))
@@ -328,7 +347,7 @@ function Turn({
 
   return (
     <div className="turn assistant">
-      {message.parts.map((part, i) => {
+      {coalesceParts(message.parts).map((part, i) => {
         if (part.type === "text") {
           return part.text.trim() ? <Markdown key={i} text={part.text} /> : null;
         }
diff --git a/app/src/server/pi.ts b/app/src/server/pi.ts
index 9d2e8dd..ccd2388 100644
--- a/app/src/server/pi.ts
+++ b/app/src/server/pi.ts
@@ -32,6 +32,12 @@ export class Pi extends Think<Env, PiState> {
   workspaceBash = false;
   waitForMcpConnections = { timeout: 15_000 };
   maxSteps = 12;
+  /**
+   * Abort-and-recover a model stream that parks without erroring — the
+   * cause of "spinning forever" turns. Set well above the slowest
+   * time-to-first-token plus the slowest MCP tool call.
+   */
+  chatStreamStallTimeoutMs = 120_000;
 
   getDefaultTimezone() {
     return "America/New_York";