From 91c375bec89a91c9f7204f1f83d573095ff4d7e8 Mon Sep 17 00:00:00 2001
From: Pileks <pilex13@gmail.com>
Date: Fri, 27 Feb 2026 16:55:23 +0100
Subject: [PATCH] update claude.md

---
 CLAUDE.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CLAUDE.md b/CLAUDE.md
index e8f43c70..5aa085d9 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -169,6 +169,9 @@ require!(account.status == Status::Active, MyError::InvalidStatus);
 require!(signer.key() == account.authority, MyError::Unauthorized);
 ```
 
+### Error Enums
+Always append new error variants to the **end** of `#[error_code]` enums. Anchor assigns error codes based on variant position (index), so inserting in the middle shifts all subsequent codes and breaks indexing/client-side error matching for deployed programs.
+
 ### After Editing Program Code
 **Always run `./rebuild.sh` after modifying any Rust code under `programs/`.** This rebuilds all programs, regenerates the SDK types, and lints — ensuring tests run against your latest changes.