Memory leak: arrayBuffers growing at ~21 GB/hour in Claude Code process

Description

Observed a severe memory leak in the Claude Code CLI process (Node.js). The arrayBuffers and external memory categories are growing at approximately 21 GB/hour, causing the process to consume several GB of RAM during normal usage.

Diagnostics

Captured via /heapdump command after ~3 minutes of uptime:

{
  "timestamp": "2026-03-14T03:49:58.892Z",
  "uptimeSeconds": 179.793,
  "memoryUsage": {
    "heapUsed": 5918248002,
    "heapTotal": 45421568,
    "external": 5877751058,
    "arrayBuffers": 5414287613,
    "rss": 1101414400
  },
  "memoryGrowthRate": {
    "bytesPerSecond": 6126000.75,
    "mbPerHour": 21031.95
  },
  "v8HeapStats": {
    "heapSizeLimit": 11871027200,
    "mallocedMemory": 5918540802,
    "peakMallocedMemory": 1187102720,
    "detachedContexts": 0,
    "nativeContexts": 1
  },
  "activeHandles": 0,
  "activeRequests": 0
}

Key Observations

• arrayBuffers at 5.4 GB after only ~3 minutes — primary suspect
• external memory at 5.8 GB — C++ objects linked to JS (Buffers, native addons)
• heapUsed is only 45 MB — the JS heap itself is healthy; the leak is entirely in native/buffer memory
• activeHandles: 0 and activeRequests: 0 — no pending I/O, yet memory is not released
• Growth rate of 21 GB/hour would exhaust most systems within an hour of use

The pattern strongly suggests Buffer or ArrayBuffer objects are being allocated (likely for file reads, streamed tool results, or response handling) and not being released or GC'd.

Environment

• Claude Code version: 2.1.72
• Node.js version: v24.3.0
• Platform: macOS Darwin 25.3.0 (Apple Silicon)
• Trigger: Manual (/heapdump), occurred during normal interactive session

Heap Snapshot

A full .heapsnapshot file was captured and is available for analysis. It is too large to attach directly but can be shared on request.

Steps to Reproduce

1. Start a Claude Code session
2. Use the CLI normally for a few minutes (tool calls, file reads, etc.)
3. Run /heapdump
4. Observe arrayBuffers and external memory in the diagnostics JSON