From db5ea78f0343d0c598b379e23fab87eef6104300 Mon Sep 17 00:00:00 2001
From: J8MAE <jamesmaedwards@gmail.com>
Date: Tue, 26 May 2026 14:00:30 -0600
Subject: [PATCH] fix(RepeatDetection): use stdout+exit 0 to inject as
 additionalContext
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The UserPromptSubmit hook contract is that the hook can return text via
stdout + exit 0, which Claude Code injects as `additionalContext` into the
model's context. stderr + exit 2 is the BLOCK pattern — it prevents the
prompt from being processed and surfaces the message to the user instead
of the model.

Before this fix, when RepeatDetection triggered:
- The user's repeated prompt was blocked
- The "⚠️ REPEAT DETECTION" warning surfaced to the user (who already knows
  they repeated; they're the one repeating)
- The model never received the signal it was supposed to act on

After this fix:
- The user's prompt is allowed to proceed
- The warning is injected into the model's context as additionalContext
- The model receives the signal to STOP and re-read the user's message

Two-line change: stderr→stdout, exit(2)→exit(0). No other behavior changed.
---
 Releases/v5.0.0/.claude/hooks/RepeatDetection.hook.ts | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Releases/v5.0.0/.claude/hooks/RepeatDetection.hook.ts b/Releases/v5.0.0/.claude/hooks/RepeatDetection.hook.ts
index a1882efc6..060fd6da0 100755
--- a/Releases/v5.0.0/.claude/hooks/RepeatDetection.hook.ts
+++ b/Releases/v5.0.0/.claude/hooks/RepeatDetection.hook.ts
@@ -106,15 +106,17 @@ function main(): void {
 
   // Threshold: 0.6 (60%) similarity triggers warning
   if (similarity >= 0.6) {
-    // Output warning to stderr — this gets injected into model context
-    process.stderr.write(
+    // UserPromptSubmit hook contract: stdout + exit 0 injects the text as
+    // additionalContext into the model's context (the desired behavior).
+    // stderr + exit 2 blocks the prompt and surfaces the warning to the
+    // user instead of injecting it for the model — wrong direction.
+    process.stdout.write(
       `⚠️ REPEAT DETECTION: This message is ${Math.round(similarity * 100)}% similar to the previous message. ` +
       `The user is likely REPEATING a request you missed. ` +
       `STOP. Re-read their message carefully. Do NOT proceed with what you were doing before. ` +
       `Address their ACTUAL request this time.`,
     );
-    // Exit 2 = blocking error, stderr fed to Claude
-    process.exit(2);
+    process.exit(0);
   }
 
   process.exit(0);