From ce34fba27b4a960fcd50b69752d4958f420e6493 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Mon, 30 Mar 2026 06:44:41 +0000
Subject: [PATCH] Add ability to set custom MTU via connect options

Allow users to specify a desired MTU per-connection by passing an `mtu`
option to `peripheral.connect({ mtu: 512 })`. Defaults to 256 if not
specified, preserving existing behavior.

Closes #71

https://claude.ai/code/session_014RCJBatLRdZ3pqdSFaAgkv
---
 lib/hci-socket/bindings.js | 3 ++-
 lib/hci-socket/gatt.js     | 4 ++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/hci-socket/bindings.js b/lib/hci-socket/bindings.js
index 6ffead84..775af7fd 100644
--- a/lib/hci-socket/bindings.js
+++ b/lib/hci-socket/bindings.js
@@ -336,7 +336,8 @@ NobleBindings.prototype.onLeConnComplete = function (
       addressType,
       address
     );
-    const gatt = new Gatt(address, aclStream);
+    const connectionParams = this._connectionQueue.length > 0 ? this._connectionQueue[0].params : {};
+    const gatt = new Gatt(address, aclStream, connectionParams && connectionParams.mtu);
     const signaling = new Signaling(handle, aclStream);
 
     this._gatts[uuid] = this._gatts[handle] = gatt;
diff --git a/lib/hci-socket/gatt.js b/lib/hci-socket/gatt.js
index 501f92b5..4af79c5e 100644
--- a/lib/hci-socket/gatt.js
+++ b/lib/hci-socket/gatt.js
@@ -56,7 +56,7 @@ const GATT_SERVER_CHARAC_CFG_UUID = 0x2903;
 const ATT_CID = 0x0004;
 /* eslint-enable no-unused-vars */
 
-const Gatt = function (address, aclStream) {
+const Gatt = function (address, aclStream, desiredMtu) {
   this._address = address;
   this._aclStream = aclStream;
 
@@ -68,7 +68,7 @@ const Gatt = function (address, aclStream) {
   this._commandQueue = [];
 
   this._mtu = 23;
-  this._desired_mtu = 256;
+  this._desired_mtu = desiredMtu || 256;
   this._security = 'low';
 
   this.onAclStreamDataBinded = this.onAclStreamData.bind(this);