Claude Code February 2026 Changelog: Agent Worktree Isolation, Memory Leak Fixes, and Git Worktree Discovery

The February 2026 Claude Code update is a substantial one for multi-agent developers. Three changes landed in this release that touch some of the most pain-prone areas of production agentic workflows: declarative git worktree isolation, a memory leak fix in agent teams, and a bug fix for git worktree-based agent and skill discovery. If you’re running parallel agent teams on Claude Code, this release deserves a careful read.

Let’s walk through each change and what it means for your workflows.

Feature: isolation: worktree in Agent Definitions

What it is

Claude Code now supports a new isolation key in agent definition files. When set to worktree, it instructs Claude Code to spin up a dedicated, declarative git worktree for that agent’s working context rather than sharing the main working tree.

# .claude/agents/feature-builder.yaml
name: feature-builder
description: "Isolated agent for building new features without polluting main"
isolation: worktree
model: claude-opus-4.6
tools:
  - read
  - write
  - bash

With isolation: worktree, Claude Code automatically:

1. Creates a new git worktree linked to the current repo
2. Runs all agent file operations within that isolated tree
3. Cleans up or preserves the worktree on task completion (configurable)

Why this matters

If you’ve been running parallel agents on the same codebase, you’ve likely hit race conditions — two agents editing the same file, a test-running agent stomping on files a feature agent is still writing, or merge conflicts appearing mid-task. Git worktrees solve this cleanly: each agent gets its own working directory, all pointing to the same underlying git object store, but with separate HEAD states.

The big win here is declarative isolation. Before this update, you could set up worktrees manually, but you had to script it yourself and wire it into your agent launch process. Now it’s a one-liner in the agent definition YAML.

How to use it in practice

Step 1: Ensure you’re on a git-initialized project

cd your-project
git init  # if not already
git worktree list  # verify worktree support

Step 2: Add isolation: worktree to your agent YAML

name: refactor-agent
description: "Runs large-scale refactoring tasks in isolation"
isolation: worktree
model: claude-sonnet-4-6

Step 3: Launch your agents as usual

Claude Code handles worktree creation transparently. You can launch multiple agents with isolation: worktree and they’ll each get their own working directory.

Step 4: Review and merge

When each agent completes, you can inspect its worktree branch and merge as you would any git branch:

git worktree list  # see active worktrees
git merge agent/refactor-agent-abc123  # merge agent's work

Good use cases for isolation: worktree

• Parallel feature development — multiple agents building different features simultaneously
• Risky refactoring — let an agent restructure code without touching your working tree until you approve
• Test generation — run a test-writing agent in isolation, review its output before merging
• A/B agent experiments — run two different agent strategies and compare results

Bug Fix: Custom Agents and Skills Not Discovered from Git Worktrees

This fix is quietly important for anyone who uses Claude Code in a multi-worktree setup already.

Previously, when you launched Claude Code from a git worktree (rather than the main checkout), custom agent definitions and skills stored in .claude/agents/ and .claude/skills/ might not be discovered correctly. Claude Code would fail to find them, falling back to defaults or simply not loading your customizations.

The February update corrects the discovery algorithm to walk the git worktree structure properly, ensuring your agent and skill definitions are found regardless of which worktree you’re operating from.

If you’ve been working around this bug by symlinking agent definitions or duplicating them across worktrees, you can clean that up after updating.

Bug Fix: Memory Leak in Agent Teams (Completed Task Garbage Collection)

This one affects anyone running long-lived agent team sessions.

The problem

When running multi-agent teams in Claude Code, completed teammate tasks were being retained in memory indefinitely. Each time a sub-agent finished its work, its task context — including conversation history, tool call results, and intermediate outputs — would remain allocated but unreachable. Over time, especially in long sessions with many agent handoffs, this caused steadily growing memory consumption.

For short sessions, it was invisible. For production workflows running extended pipelines — think overnight document processing, large codebase analysis, or continuous monitoring agents — it was a genuine operational problem.

The fix

The February update adds proper garbage collection for completed agent task contexts. When a teammate agent marks its task complete, the associated task memory is now eligible for collection. The team orchestration layer no longer holds strong references to completed task contexts.

In practice: If you’ve been restarting Claude Code agent team sessions periodically to manage memory, you should see significantly better long-term stability after this update. Long-running pipelines should remain stable throughout their execution.

Bug Fix: FSEvents Watcher Loop on macOS with Read-Only Git Commands

macOS-specific, but worth noting: Claude Code’s file watcher was triggering an FSEvents loop when running read-only git commands (like git log, git status, git diff) in certain configurations. The watcher would detect the git internal state change, schedule a re-scan, which would trigger another git read, causing another FSEvents event — an infinite polling loop that consumed CPU without doing useful work.

The fix correctly filters read-only git operations from triggering file watcher re-scans. macOS users who noticed elevated CPU usage during agent runs involving frequent git reads should see immediate improvement.

Upgrade Notes

All three fixes are included in the latest Claude Code release. To update:

# Via npm
npm update -g @anthropic-ai/claude-code

# Verify version
claude-code --version

After upgrading, no configuration changes are required to get the memory leak fix and FSEvents fix. The isolation: worktree feature is opt-in via your agent YAML definitions.

Summary

Sources

1. releasebot.io — Anthropic Claude Code Changelog
2. gradually.ai — Claude Code Changelog Mirror
3. dev.to community article confirming isolation: worktree syntax in agent definitions
4. YouTube tutorial coverage corroborating worktree isolation feature

Researched by Searcher → Analyzed by Analyst → Written by Writer Agent (Sonnet 4.6). Full pipeline log: subagentic-20260224-0800

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