Day 44

Boris Cherny's 14 Hidden Features

Day 43 Day 45

Boris Cherny Thread

14 HIDDEN CLAUDE CODE FEATURES
MOST PEOPLE DON'T USE

From the engineer who builds Claude Code — every feature he uses daily, with commands you can run right now.

Boris Cherny

@bcherny — Engineer at Anthropic, builds Claude Code

X / Mar 30, 2026

hidden features

feature categories

new installs needed

Mobile + Sessions

Mobile App — Code From Your Phone

Claude Code has a full mobile app. Write code, review diffs, run agents — from iOS or Android. No laptop required.

# Claude app > Code tab (left sidebar)
$ Open Claude app on iOS/Android
# Full agent, full context, mobile

TipStart a session on desktop, continue on phone while walking. Same context.

Teleport Sessions Across Devices

Move sessions between mobile, web, desktop, and terminal. Cloud sessions sync automatically. Local sessions teleport on demand.

$ claude --teleport
# Continue cloud session on local machine
$ /remote-control
# Control local session from phone/web

TipEnable "Remote Control by default" in settings for always-on phone access.

/loop and /schedule — Autopilot Mode

Schedule Claude to run automatically at set intervals, up to a week. Boris runs dozens of loops locally at all times.

$ /loop 5m /babysit
# Auto-rebase, address code review
$ /schedule "every morning" /digest
# Daily standup summary at 9am

TipCombine /loop with /babysit-prs to auto-address review comments on all PRs.

Hooks — Deterministic Agent Lifecycle

Run shell commands at specific points in the agent lifecycle. Load context on start, log bash commands, route permissions to WhatsApp.

// .claude/settings.json
"hooks": {
  "SessionStart": [{ "command": "cat context.md" }],
  "PreToolUse": [{ "command": "./log.sh" }]
}

TipUse PreToolUse hooks to block dangerous commands (rm -rf, force push) automatically.

Visual Verification

Cowork Dispatch — Remote Control Everything

Catch up on Slack, manage files, do things on your laptop from anywhere. Dispatch uses your MCPs, browser, and Desktop tools securely.

# From claude.ai on your phone:
> "Check my Slack unreads and
  summarize what needs attention"
# Runs on your laptop, replies to phone

TipBoris uses Dispatch daily when away from his computer. Not just for code.

Chrome Extension — Frontend Verification

Give Claude a way to see what it builds. Claude iterates until the result is great — like any engineer with a browser open.

# Install: Chrome Web Store > Claude Code
$ claude "build a dashboard"
# Claude sees the browser, iterates on UI
# No more blind coding

Tip"Give Claude a way to verify its output" — the most important tip in the thread.

Desktop App — Auto-Start & Test Servers

Claude Desktop bundles a built-in browser. It auto-runs your web server and tests it visually. Full feedback loop, no setup.

# Claude Desktop app:
> "Start the dev server and test
  the login flow"
# Launches server + built-in browser

TipDesktop app + Chrome extension = Claude sees everything it builds, automatically.

Fork Your Session — /branch

Split a running session into two. Explore an alternative approach without losing your current context or progress.

$ /branch
# Forks current session in-place
$ claude --resume <id> --fork-session
# Fork from CLI with session ID

TipFork before trying a risky refactor. If it fails, your original session is untouched.

Power User

/btw — Side Queries While Agent Works

Ask quick questions without interrupting the running task. The agent keeps working while you get answers on the side.

# While Claude is refactoring:
$ /btw "what's the default port
  for this framework?"
# Answers instantly, agent continues

TipBoris uses /btw "all the time" — treats it like a quick Cmd+K search.

Git Worktrees — Parallel Everything

Run dozens of Claude instances in the same repo simultaneously. Each gets its own worktree. Essential for parallel work at scale.

$ claude -w
# Start new session in fresh worktree
# Boris runs dozens at all times
# Each agent = isolated branch

TipCombine with /batch for massive parallel migrations across hundreds of files.

/batch — Fan Out Massive Changesets

Interviews you, then fans out work to as many worktree agents as needed — dozens, hundreds, even thousands. For large migrations.

$ /batch
# Claude: "What do you want to change?"
# "Migrate all React class components"
# Spawns 50+ parallel worktree agents

TipWorks best for parallelizable work: migrations, bulk renames, test generation.

--bare — 10x Faster SDK Startup

Skip auto-loading CLAUDE.md, settings, and MCPs. For non-interactive/SDK usage, explicitly specify what to load instead.

$ claude -p --bare "summarize this"
# Skips: CLAUDE.md, settings, MCPs
# 10x faster startup for scripts
# Use --system-prompt for custom ctx

TipEssential for CI/CD pipelines and SDK automations where startup speed matters.

--add-dir — Multi-Repo Access

Give Claude access to additional folders and repos. Not just visibility — full read/write permissions across repositories.

$ claude --add-dir ../other-repo
# Claude can now read + write both repos
$ /add-dir ../shared-libs
# Add more dirs mid-session

TipPerfect for monorepo-like work across separate repositories. Use mid-session too.

--agent — Custom System Prompt + Tools

Define custom agents in .claude/agents/ with their own system prompts, tools, and behaviors. A powerful primitive most overlook.

# .claude/agents/reviewer.md
$ claude --agent=reviewer
# Loads custom prompt + scoped tools
# Each agent = specialized role

TipThink of agents as specialized team members. Reviewer, deployer, researcher — each with its own rules.

“Give Claude a way to verify its output. Once you do that, Claude will iterate until the result is great.”

— Boris Cherny, Engineer at Anthropic

Save this. Use these daily. All 14.

Day 43: Second Brain Architecture

Day 45: Cost Optimization Stack