Imported from josiahsiegel/claude-plugin-marketplace (plugins/context-master/skills/context-master/SKILL.md) via skills.sh. Install upstream with npx skills add josiahsiegel/claude-plugin-marketplace --skill context-master. Copyright stays with the author.

Context Master

Universal context management and planning skill for complex tasks, long sessions, and multi-file projects. Works the same way whether you are in the Web app, the API, or Claude Code CLI; CLI-specific bonuses live in references/claude-code-cli.md.

This SKILL.md is intentionally short. Detailed material lives in references/ — load only what you need.

When to activate

Activate proactively whenever the request matches one of:

• Multi-file project (3+ related files, websites, apps, APIs, doc sets).
• Architecture or technology decision ("should we use X or Y", "which approach…").
• Research / comparison / tradeoff analysis.
• Refactoring or migration work.
• Long coding session where context efficiency matters.
• Any task with 3+ sequential steps or shared dependencies.

If the request is a single file with no dependencies, skip this skill.

The 5-step workflow (memorize this)

For any multi-file project — websites, apps, APIs, documentation sets — run these five steps in order:

1. STOP — do not create any files yet.
2. PLAN — use extended thinking or a planning document (both equally valid; see references/multi-file-planning.md).
3. ANNOUNCE — state the file list and creation order to the user.
4. CREATE — write files in optimal order (foundations before dependents).
5. VERIFY — check that every reference resolves; fix issues before declaring done.

Worked example (portfolio website)

User: "Create a portfolio with home, about, projects, and contact pages."

Step 1 STOP    -- do not start with index.html.
Step 2 PLAN    -- "Think hard about architecture: 5 files needed,
                  styles.css is the shared dependency."
Step 3 ANNOUNCE -- "I'll create:
                  1. styles.css       (shared styling)
                  2. index.html       (references styles.css)
                  3. about.html
                  4. projects.html
                  5. contact.html"
Step 4 CREATE   -- write files in that order.
Step 5 VERIFY   -- every HTML file links styles.css; navigation resolves.

Result: no refactor, no re-export, no broken links.

The full template, optimal-order patterns by project type (website / React / backend API / etc.), and verification checklists are in references/multi-file-planning.md.

Core principles (one line each)

1. Plan before you write — extended thinking or planning doc, never both skipped.
2. Foundations first — shared dependencies (CSS, config, base classes, schemas) precede dependents.
3. Delegate deep analysis to isolated contexts — subagents (CLI) or thinking artifacts (Web/API) keep the main thread clean.
4. Phase boundaries — name each phase ("Phase 1 complete; moving to Phase 2: …") so context doesn't blur.
5. Artifacts over inline content — long code or docs live in artifacts/files, not chat history.
6. Progressive disclosure — ask for one slice at a time; don't batch unrelated steps.
7. Signal resets — say "setting aside the previous approach…" when changing direction.
8. Reflect after large projects — was it planned? Did references break? Use the post-project checklist in references/multi-file-planning.md.

Full rationale and examples for every principle: references/universal-best-practices.md.

Token-savings rule of thumb

A 200K-token context window holds roughly 16-17 medium projects with planning, 7-8 without — a 2.1x effective increase. Numbers and methodology in references/multi-file-planning.md.

Passive deep-thinking architecture

The single most powerful pattern for context efficiency: route deep reasoning into an isolated space and return a short summary to the main thread.

• Claude Code CLI: /agent deep-analyzer "Ultrathink about [decision]" — ~5K tokens of reasoning happens out-of-band; main context receives a ~200-token summary (~23x efficiency).
• Web / API: "Create a deep-analysis artifact and ultrathink about [decision]" — same idea, artifact instead of subagent.

Triggers, anti-patterns, and ready-made prompts: references/thinking-delegation.md.

Common workflows (pointers only)

Each of these has a step-by-step procedure in references/workflows.md:

• Workflow 0 — Multi-file website/project creation (the default — same 5 steps above with extra detail).
• Workflow 1 — Complex decision-making (architecture, tech choice).
• Workflow 2 — Complex feature development (analysis → design → implement → test → integrate).
• Workflow 3 — Research and technology evaluation.
• Workflow 4 — Code generation and iteration via artifacts.
• Workflow 5 — Refactoring with isolated analysis.

Anti-patterns (avoid these)

Quick list — examples and fixes in references/anti-patterns.md:

1. Creating files before planning — wastes context on refactors.
2. Asking for everything at once — overloads context and produces shallow output.
3. Inlining long code/docs in chat — bloats history; use artifacts/files.
4. Letting deep reasoning happen in main thread — costs ~5K tokens that could be ~200.
5. No phase boundaries — context blurs across unrelated subtasks.

Troubleshooting

When sessions drift (responses unfocused, conversations getting too long, code regenerating instead of editing, extended thinking not engaging), see references/troubleshooting.md for a symptom → remedy table covering Web/API and CLI separately.

Claude Code CLI bonuses

If you are running in Claude Code CLI, you also get:

• /clear, /compact, /continue — built-in context controls.
• /agent <name> — delegate to an isolated subagent.
• CLAUDE.md — persistent project memory.
• Helper scripts for generating CLAUDE.md and subagent definitions.

Details, script invocations, and the deep-analysis delegation patterns: references/claude-code-cli.md.

Skill–subagent integration patterns (when both are available) live in references/agent-skills-integration-2025.md. Long-form context strategies and subagent prompt patterns: references/context_strategies.md and references/subagent_patterns.md.

Reference map

Success indicators

• You announced the plan before creating any file.
• Foundation files (CSS, config, schemas) were written before dependents.
• No reference broke on first run; no refactor was needed.
• Deep reasoning happened in a subagent or artifact, not the main thread.
• Phases were named as you crossed them.

If any of those failed, walk back through references/anti-patterns.md and references/multi-file-planning.md post-project section before the next task.