From 058e2f4df4a1cdd4c620d0cc440774e113bfefc5 Mon Sep 17 00:00:00 2001
From: Space-Banane <paulwaehner923@gmail.com>
Date: Wed, 8 Apr 2026 20:12:36 +0200
Subject: [PATCH] Implement unique filename generation to prevent overwriting
 existing session files

---
 HOOK.md    |  3 +++
 README.md  |  7 +++++++
 handler.ts | 22 +++++++++++++++++++++-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/HOOK.md b/HOOK.md
index c95c455..cebf1d0 100644
--- a/HOOK.md
+++ b/HOOK.md
@@ -17,6 +17,9 @@ metadata:
 Writes full user/assistant transcript context from the previous session into
 `<workspace>/memory/YYYY-MM-DD-slug.md` when `/new` or `/reset` runs.
 
+This hook avoids overwriting existing files by choosing a unique filename
+when a collision occurs (it appends `-1`, `-2`, etc. to the base name).
+
 Differences from bundled session-memory:
 
 - Uses full session context in output file
diff --git a/README.md b/README.md
index 4d488c7..63842da 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,8 @@ Custom OpenClaw session-memory hook.
 - Saves the **full** user/assistant session context into `workspace/memory/`
 - Uses `agents.defaults.userTimezone` for date/time formatting
 - Uses a slugged filename, with slug generation based on a small excerpt
+ - Avoids overwriting existing files: if a filename already exists the hook
+   appends `-1`, `-2`, ... to produce a unique filename.
 
 ## Disable the bundled hook
 
@@ -42,3 +44,8 @@ Or set it false in config:
 ## Notes
 
 This repo is intentionally lightweight, it exists so the custom hook can live in the managed hooks directory and stay separate from the bundled one.
+
+If you prefer atomic creation to fully eliminate a race window (two processes
+creating the same new filename simultaneously), replace the simple existence
+check with an atomic open/write using `fs.open(..., 'wx')` or write to a
+temporary file and `fs.rename()` it into place.
diff --git a/handler.ts b/handler.ts
index 4438685..f7679ce 100644
--- a/handler.ts
+++ b/handler.ts
@@ -197,6 +197,26 @@ function buildSlugExcerpt(full: string): string {
   return tail.slice(-3000);
 }
 
+async function getUniqueFilePath(dir: string, filename: string): Promise<string> {
+  const candidate = path.join(dir, filename);
+  try {
+    await fs.access(candidate);
+  } catch {
+    return candidate;
+  }
+
+  const parsed = path.parse(filename);
+  for (let i = 1; ; i += 1) {
+    const name = `${parsed.name}-${i}${parsed.ext}`;
+    const p = path.join(dir, name);
+    try {
+      await fs.access(p);
+    } catch {
+      return p;
+    }
+  }
+}
+
 async function generateSlug(params: {
   excerpt: string;
   cfg: AnyObj;
@@ -274,7 +294,7 @@ const handler = async (event: {
     await fs.mkdir(memoryDir, { recursive: true });
 
     const filename = `${dateStr}-${slug}.md`;
-    const memoryFilePath = path.join(memoryDir, filename);
+    const memoryFilePath = await getUniqueFilePath(memoryDir, filename);
 
     const source = typeof context.commandSource === "string" ? context.commandSource : "unknown";