From 845be553f76e1877ad1f974357264947faec2b8a Mon Sep 17 00:00:00 2001
From: chorus-codes <280607145+chorus-codes@users.noreply.github.com>
Date: Wed, 27 May 2026 17:14:49 +1000
Subject: [PATCH] fix(mcp): drop redundant events[] from wait_for_chat response

The handler captured every progress event into an array and embedded
the whole thing into the tool result. An 8-reviewer chat routinely hit
50KB+, exceeding the MCP client's per-result token budget and forcing
the client to spill to file + chunked re-read.

The events are already streamed live via notifications/progress, so the
embedded copy was pure duplication. Replace with eventCount for debug.

Closes the long-standing "wait_for_chat results spill to file" issue
noted in reference_chorus_mcp_result_parsing memory.
---
 src/mcp/index.ts | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/mcp/index.ts b/src/mcp/index.ts
index e9bc4e1..a05f210 100644
--- a/src/mcp/index.ts
+++ b/src/mcp/index.ts
@@ -141,9 +141,16 @@ mcpServer.registerTool(
         void sendProgress(msg);
       });
 
+      // Do NOT embed `progressEvents` in the response. Every event was
+      // already streamed live via `notifications/progress` (see sendProgress
+      // above); duplicating them here only inflates the tool result.
+      // An 8-reviewer chat routinely produced 50KB+ payloads that exceeded
+      // the MCP client's per-result token budget — the client then spills
+      // the whole blob to a file and forces a chunked re-read. `eventCount`
+      // gives callers the cardinality for debug without the bloat.
       const response = {
         ...(result as Record<string, unknown>),
-        events: progressEvents,
+        eventCount: progressEvents.length,
       };
 
       return {