From 73f5dcc756df942fd92050bde1d7ecbbf1a19b1b Mon Sep 17 00:00:00 2001
From: catwithtudou <949812478@qq.com>
Date: Sun, 7 Jun 2026 14:48:41 +0800
Subject: [PATCH] fix: preserve existing AGENTS.md during Codex sync

---
 src/community/openai/codex-agent-runner.ts    |  6 +++++-
 .../openai/codex-agent-runner.test.ts         | 21 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/community/openai/codex-agent-runner.ts b/src/community/openai/codex-agent-runner.ts
index 7cfb9fd..e1b4208 100644
--- a/src/community/openai/codex-agent-runner.ts
+++ b/src/community/openai/codex-agent-runner.ts
@@ -510,12 +510,16 @@ export class CodexAgentRunner implements AgentRunner {
 
       const agentsMdPath = join(cwd, "AGENTS.md");
 
-      // Skip write when contents are identical to avoid file-watcher churn.
       if (existsSync(agentsMdPath)) {
         const existing = readFileSync(agentsMdPath, "utf-8");
+        // Skip write when contents are identical to avoid file-watcher churn.
         if (existing === normalized) {
           return;
         }
+        logger.warn(
+          "AGENTS.md already exists; skipping CLAUDE.md sync to avoid overwriting project instructions",
+        );
+        return;
       }
 
       writeFileSync(agentsMdPath, normalized, "utf-8");
diff --git a/tests/community/openai/codex-agent-runner.test.ts b/tests/community/openai/codex-agent-runner.test.ts
index bfa2f4f..6b5eadd 100644
--- a/tests/community/openai/codex-agent-runner.test.ts
+++ b/tests/community/openai/codex-agent-runner.test.ts
@@ -415,6 +415,27 @@ describe("CodexAgentRunner._parseStreamLine", () => {
     expect(agents).not.toContain("Claude Code");
   });
 
+  test("syncing AGENTS.md preserves existing project instructions", () => {
+    const cwd = mkdtempSync(join(tmpdir(), "agentara-codex-runner-"));
+    tempDirs.push(cwd);
+    const existingAgents = "# Project Instructions\n\nKeep this project's AGENTS.md.\n";
+    writeFileSync(
+      join(cwd, "CLAUDE.md"),
+      "# Title\n\nAs Claude Code, use the shared instructions.\n",
+      "utf-8",
+    );
+    writeFileSync(join(cwd, "AGENTS.md"), existingAgents, "utf-8");
+
+    const runner = new CodexAgentRunner() as unknown as Record<
+      string,
+      CallableFunction
+    >;
+    runner["_syncAgentsMd"]!(cwd);
+
+    const agents = readFileSync(join(cwd, "AGENTS.md"), "utf-8");
+    expect(agents).toBe(existingAgents);
+  });
+
   test("builds resume args with runnerSessionId when available", () => {
     const runner = new CodexAgentRunner() as unknown as Record<
       string,