From 62d6a13ac9228e5ea9ae0e56811b7fd4479563cb Mon Sep 17 00:00:00 2001
From: Natalie <natalie@lilithuwu.com>
Date: Sun, 17 May 2026 02:19:58 -0700
Subject: [PATCH] =?UTF-8?q?feat(@projects/@magic-civilization):=20?=
 =?UTF-8?q?=E2=9C=A8=20add=20auto-respawn=20harness=20logic?=
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Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>
---
 src/simulator/api-gdext/src/player_api.rs |  1 -
 tooling/claude-player-mcp/src/harness.ts  |  6 ++++++
 tooling/claude-player-mcp/src/index.ts    | 15 +++++++++++++--
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/simulator/api-gdext/src/player_api.rs b/src/simulator/api-gdext/src/player_api.rs
index dcef1347..74609592 100644
--- a/src/simulator/api-gdext/src/player_api.rs
+++ b/src/simulator/api-gdext/src/player_api.rs
@@ -276,7 +276,6 @@ fn normalize_int_zero_floats(src: &str) -> String {
             j += 1;
         }
         if bytes[j].is_ascii_digit() {
-            let digit_start = j;
             while j < bytes.len() && bytes[j].is_ascii_digit() {
                 j += 1;
             }
diff --git a/tooling/claude-player-mcp/src/harness.ts b/tooling/claude-player-mcp/src/harness.ts
index 9c7428c6..dcbd3caa 100644
--- a/tooling/claude-player-mcp/src/harness.ts
+++ b/tooling/claude-player-mcp/src/harness.ts
@@ -47,6 +47,12 @@ export class HarnessClient {
   private nextId = 1;
   private closed = false;
 
+  /** True after the child exits (clean or crash). Lets the MCP layer
+   *  detect a dead harness and respawn instead of erroring forever. */
+  get isClosed(): boolean {
+    return this.closed;
+  }
+
   constructor(opts: HarnessOptions) {
     this.opts = {
       env: {},
diff --git a/tooling/claude-player-mcp/src/index.ts b/tooling/claude-player-mcp/src/index.ts
index 426d55f8..6dc4533a 100644
--- a/tooling/claude-player-mcp/src/index.ts
+++ b/tooling/claude-player-mcp/src/index.ts
@@ -108,8 +108,19 @@ interface HarnessHolder {
 const holder: HarnessHolder = { client: null };
 
 function getOrCreateClient(): HarnessClient {
-  if (holder.client !== null) return holder.client;
-  emitStderr(`spawning harness: ${serverScript()}`);
+  // Auto-respawn: if the held client died (godot child crashed, was killed by
+  // a developer iterating on the dylib, etc.) treat it as `null` so the next
+  // request gets a fresh harness. Without this, every Claude Code session
+  // that hit a single harness crash would need a full restart to recover.
+  if (holder.client !== null && !holder.client.isClosed) {
+    return holder.client;
+  }
+  if (holder.client !== null) {
+    emitStderr("previous harness closed; respawning");
+    holder.client = null;
+  } else {
+    emitStderr(`spawning harness: ${serverScript()}`);
+  }
   const client = new HarnessClient({
     serverScript: serverScript(),
     env: harnessEnv(),