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Claude Mastery
Daily newsletter on becoming the best Claude Code operator there is. CLI power moves, agent architecture, operator thinking, ecosystem intel, and hands-on practice labs.
22
Issues
114
Topics
5
Categories
CLI: 25
Ecosystem: 25
Agent: 22
Lab: 22
Operator: 20
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Archive
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#22
Apr 24, 2026
Weekday Edition
5 topics
·
avg quality 3.8/5
CLIv2.1.119 — /config Finally Persists, --from-pr Speaks GitLab/Bitbucket, --print Honors Agent Frontmatter
OperatorThe April 23 Postmortem — Three Silent Regressions, Seven Weeks, One Honest Writeup
AgentPostToolUse Now Has duration_ms — Use It to Catch Your Own Silent Regressions
EcosystemAgentBox SDK — Drop Claude Code Into E2B, Modal, Daytona, Vercel, or Local Docker
LabWire PostToolUse duration_ms to SQLite and Alert When a Tool Starts Drifting
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#21
Apr 23, 2026
Weekday Edition
5 topics
·
avg quality 3.6/5
CLIv2.1.118 — /cost and /stats Are Gone. /usage Took Their Place.
AgentHooks Can Now Call MCP Tools Directly
OperatorClaude Code in the Outer Loop — Five SRE Patterns That Work
EcosystemBroccoli — Self-Hosted Linear→PR In Your Own GCP Project
LabCompose Your Auto Mode Allow-List Without Losing the Built-Ins
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#20
Apr 22, 2026
Weekday Edition
5 topics
·
avg quality 3.4/5
CLIv2.1.117 — Opus 4.7 Was Autocompacting at 200K. That's Fixed.
OperatorAnthropic Is A/B Testing Claude Code Out Of Pro. Build For Portability Anyway.
EcosystemGemini Plugin for Claude Code — ACP Bridge, Not a Model Switch
EcosystemOpen Chronicle — Screen Capture as Agent Memory (macOS Only, But Interesting)
LabConfirm Your Opus 4.7 Autocompaction Stops Firing at 200K
Read Post →
#19
Apr 21, 2026
Weekday Edition
5 topics
·
avg quality 3.6/5
CLIv2.1.116 — /resume 67% Faster, Main-Thread Agent Hooks, and a gh Rate-Limit Hint
AgentRalph — The While-Loop Coding Agent, Now Containerized and Auditable
OperatorYour Plugin Marketplace Is a Governance Layer, Not a Git Repo
Ecosystemctx — Workstream-Bound /resume That Works Across Claude Code and Codex
LabBoot Ralph In a Dev Container Tonight and Let It Grind a Toy Backlog
Read Post →
#18
Apr 20, 2026
Weekday Edition
5 topics
·
avg quality 3.4/5
CLIFuelGauge — A Rate-Limit Status Line With Zero Node Dependency
AgentGEPA-Evolved SKILL.md Files — Haiku 4.5 From 79% to 98% on a Real Repo
OperatorClaude Code as Your Stack's Gatekeeper — What It Actually Picks
Ecosystemclaude-code-rust — A Native Rust TUI That Skips the V8 Heap
LabRun a 30-Minute Tool-Gatekeeper Audit On Your Next Project
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#17
Apr 19, 2026
Weekend Deep Dive
4 topics
·
avg quality 4.2/5
EcosystemThe MCP STDIO Supply Chain Advisory — 10+ CVEs, Zero‑Click Windsurf, and the Prompt That Saved Claude Code
AgentWhy Auto Mode's Classifier Can't See What Claude Said — And Why That's the Design
CLIUnclog — Measure and Evict Your Context Bloat Before Your First Message
LabAudit Every MCP Server You've Ever Installed
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#16
Apr 18, 2026
Weekend Deep Dive
6 topics
·
avg quality 3.8/5
CLIv2.1.113 — The Native Binary Transition
CLIThe Bash Permission Bypass Hardening in v2.1.113
AgentThe 10-Minute Subagent Watchdog — Stalls Now Fail Loud
OperatorAudit Your Own Token Waste With Haiku as Judge
EcosystemSelf-Care — 14-Category Trace Triage for Your Agents
LabVerify Your Claude Code Binary's Cryptographic Chain
Read Post →
#15
Apr 17, 2026
Weekday Edition
6 topics
·
avg quality 4.0/5
CLIv2.1.111 — The Opus 4.7 Release
CLI/ultrareview — Multi-Agent Cloud Code Review
AgentAdaptive Thinking Kills Fixed Budgets — What Changes for Your Agents
OperatorSix Ways Opus 4.7 Changes Your Workflow
EcosystemTask Budgets — Advisory Token Caps for Agentic Loops
LabCalibrate Your Setup for Opus 4.7
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#14
Apr 16, 2026
Weekday Edition
5 topics
·
avg quality 3.4/5
CLIv2.1.110 — /tui Live Switching, Push Notifications, and 20 Fixes
AgentLazy-Load Your Skills — Cut 53% of Metadata Tokens
OperatorWhat 12 AI Sessions Reveal About Security Defaults
EcosystemUnkode — Architecture Drift Detection as a Claude Code Skill
LabReorganize Your Skills for Lazy Loading
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#13
Apr 15, 2026
Weekday Edition
5 topics
·
avg quality 4.2/5
CLIv2.1.108 — Prompt Cache TTL Control, /recap, and 14 Fixes
AgentRoutines — Cloud-Hosted Automations with Three Trigger Types
OperatorThree Tiers of Automated Execution — and When to Use Each
EcosystemClaude Code Desktop Gets a Full Redesign
LabWire Up Your First Cloud Routine
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#12
Apr 14, 2026
Weekday Edition
4 topics
·
avg quality 3.5/5
CLIv2.1.105 — PreCompact Hooks, Stream Recovery, and the Skill Cap Bump
AgentCompaction-Proof Agent Identity — Three Defense Layers
EcosystemAgentsView — Cross-Agent Session Analytics from the Creator of pandas
LabBuild a PreCompact Identity Guard
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#11
Apr 13, 2026
Weekday Edition
6 topics
·
avg quality 3.3/5
CLIThe Prompt Cache Tax — v2.1.100+ Burns 20K Extra Tokens Per Turn
AgentPersistent Agent Sessions with Claudraband's Daemon Mode
OperatorThe Compaction Decision — /clear, /compact, or Keep Going?
EcosystemRevdiff — Structured Diff Review with Claude Code Plugin
Ecosystemclaude-notifications-go — 529-Star Smart Notification Plugin
LabDiagnose and Fix Your Prompt Cache Health
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#10
Apr 12, 2026
Weekend Deep Dive
6 topics
·
avg quality 4.5/5
CLIFarmer — Approve Agent Requests from Your Phone
AgentFork Agents — Why Claude Code's Biggest Optimization Is Economic
AgentMemory Architecture — Files Over RAG, LLM Recall Over Embeddings
OperatorThe Deterministic Permission Pipeline — How Claude Code Decides What to Allow
Ecosystemclaude-code-from-source — 18 Chapters of Reverse-Engineered Architecture
LabBuild a Phone-Controlled Agent Approval System
Read Post →
#9
Apr 11, 2026
Weekend Deep Dive
7 topics
·
avg quality 4.1/5
CLIv2.1.101 — The Biggest Bug-Fix Release Yet
CLIThe Monitor Tool — From Polling Loops to Event-Driven Agents
AgentThe Advisor Strategy — Opus as On-Demand Strategist
OperatorFour Runtime Patterns from Claude Code's Source
EcosystemAgentLint — 68 Hook Rules, Zero LLM Calls
EcosystemTwill.ai — Cloud Agents That Deliver Pull Requests
LabBuild an Advisor-Powered Code Review Pipeline
Read Post →
#8
Apr 10, 2026
Weekday Edition
5 topics
·
avg quality 3.4/5
CLIv2.1.98 Patched Six Bash Permission Bypasses
AgentSubprocess Sandboxing: PID Isolation and Script Caps
OperatorPlugin Trust After the Vercel Telemetry Scandal
EcosystemEngram: Zero-Dep Persistent Memory in a Single Go Binary
LabAudit Your Installed Plugins for Telemetry Leaks
Read Post →
#7
Apr 9, 2026
Weekday Edition
5 topics
·
avg quality 3.2/5
CLIFocus View — The Three-State Terminal Navigator
Agentv2.1.97 Fixed Four Agent-Killing Bugs
OperatorDesign for Resumability — Lessons from 7 Resume Fixes
Ecosystemclaude-on-a-leash: Deterministic Security Without Sandbox Overhead
LabMaster the Three-State Navigator in 10 Minutes
Read Post →
#6
Apr 8, 2026
Weekday Edition
5 topics
·
avg quality 3.4/5
CLIAuto-Name Sessions with hookSpecificOutput.sessionTitle
AgentSandbox Your Agents: Runtime Isolation with Bubblewrap and Firejail
OperatorAgent = Model + Harness: The Mental Model That Changes Everything
EcosystemKerf-CLI: SQLite-Backed Cost Intelligence for Claude Code
LabSandbox Claude Code with Bubblewrap in 10 Minutes
Read Post →
#5
Apr 7, 2026
Weekday Edition
5 topics
·
avg quality 3.2/5
CLIclaude-profile: Run Multiple Subscriptions Side by Side
AgentThe LLM Wiki Pattern: Compile Knowledge That Compounds Across Sessions
OperatorThe Skill Metadata Budget: Why 33% of Your Skills Are Invisible
EcosystemRepowise: Codebase Intelligence That Goes Beyond File Reading
LabIndex Your Codebase with Repowise's Four Intelligence Layers
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#4
Apr 6, 2026
Weekday Edition
5 topics
·
avg quality 3.2/5
CLI/cost Per-Model and Cache-Hit Breakdown
AgentMCP Context Optimization: Tool Search and Result Persistence
OperatorSilent Fake Success — The Deadliest Agent Failure Mode
EcosystemVibeAround: Telegram-to-Claude-Code with Session Handover
LabAudit Your Agents for Silent Fake Success
Read Post →
#3
Apr 5, 2026
Weekend Deep Dive
5 topics
·
avg quality 4.6/5
CLIUltraplan: The Cloud-to-Terminal Planning Bridge
AgentCustom Subagent Masterclass: 17 Fields, 5 Scopes, Full Autonomy
Operator~/.claude/ Security Audit: Structure Is Not Security
EcosystemConductor: Multi-Session Orchestration via MCP + Remote Control API
LabBuild a Security-Hardened Custom Subagent Fleet
Read Post →
#2
Apr 4, 2026
Weekend Deep Dive
5 topics
·
avg quality 4.4/5
CLIHooks Masterclass: 26 Events, Conditional Logic, and Production Chains
AgentAgent Teams: Multi-Session Orchestration with Shared Tasks
OperatorWalls Beat Signs: Why CLAUDE.md Rules Fail Under Pressure
EcosystemRemembrallMCP: Persistent Code Intelligence That Cuts Token Usage by 98%
LabBuild a Hook-Based Agent Supervision Framework
Read Post →
#1
Apr 3, 2026
Weekday Edition
5 topics
·
avg quality 3.4/5
CLIRate Limit Monitoring in the Statusline
AgentThe defer Hook — Pause-and-Resume for Headless Agents
OperatorCLAUDE.md as Attention Budget — The 150-Instruction Ceiling
EcosystemOpenAI Ships a Codex Plugin for Claude Code
LabBuild a Rate Limit Fuel Gauge
Read Post →