claude-code-capability-primer

Use when unsure which Claude Code capability fits a task, when about to single-thread large/cross-cutting/repetitive work, or when you or the user ask what Claude Code can do — loads the full capability map (signal → capability) and points to the deep-dive skills.

Use when building custom AI agents headlessly, embedding Claude Code tools in an app, or running scripted/cron agents—need SDK package names, setup, core API entry points, supported languages, and relation to Claude Code CLI and Messages...

Use when needing to understand or manage background agents, long-running tasks, polling, scheduling, or async work in Claude Code without blocking the session.

Use when you need to undo code edits, explore alternatives without losing a starting point, recover from a bad edit path, or restore previous conversation state — press Esc Esc or run /rewind to open checkpoints menu.

Use when a task is too big for one context — broad audits, multi-file migrations, multi-source research, or parallel multi-dimension review — and you want to fan out and orchestrate many subagents deterministically with the Workflow tool (requires ultracode / explicit opt-in).

Use when deciding how to work on a task - choosing effort level, model, or fast mode to balance reasoning depth, speed, and token cost.

Use when setting up or debugging Claude Code GitHub Actions automation, or deciding whether to route CI/CD tasks to GitHub Actions vs local session.

Use when configuring automated lifecycle commands (hooks) in Claude Code settings.json — event types, matcher syntax, exit codes, JSON output, path placeholders.

Use when configuring MCP servers in Claude Code — connecting external tools (GitHub, Stripe, Sentry, databases), choosing transports (HTTP, stdio, WebSocket), managing scopes, handling authentication, scaling with tool search, and decidi...

Use when building, debugging, or installing Claude Code plugins—understanding plugin structure, CLI commands, marketplace configuration, or skill/agent packaging.

Use when you need to understand, create, trigger, or debug Claude Code skills—reusable workflows defined in SKILL.md files with YAML frontmatter.

Use when you have research, exploration, a large review, or 2+ independent tasks to run — spawn subagents (the Agent/Task tool), in parallel when possible, to do focused work and keep the main context clean.