Local-first CLI and TypeScript library that reads JSONL session logs from Claude Code, Codex, and 13 other coding agents to produce daily/weekly/monthly/session/billing-block reports of token spend.
Day-to-day Cypress CLI commands and config patterns — interactive runs, headless CI, intercepts, sessions, component testing, and Playwright comparison.
Daily-driver reference for esbuild — bundle CLI, transform API, JS API patterns, common build recipes.
Day-to-day Jest CLI commands and config patterns — running tests, mocks, snapshots, coverage, watch mode, and migration tips.
The ncu CLI from npm-check-updates rewrites package.json to bump dependency versions — interactive mode, filters, doctor rollback, and workspaces support.
Daily-driver reference for nodemon — watch flags, exec patterns, config files, lifecycle events.
Daily-driver reference for rollup — CLI commands, multi-format output, plugin chain patterns, library publishing config.
Daily-driver reference for the ts-node CLI — REPL, transpile-only mode, ESM loader, common script patterns.
Daily-driver reference for the tsx CLI — run TS files, watch mode, ESM/CJS handling, Node loader integration.
Day-to-day Turborepo CLI commands and turbo.json config patterns — pipelines, filters, remote cache, prune, and CI integration.
Vercel's official CLI for deploying frontend apps, managing environments, syncing env vars, tailing logs, and rolling back via alias re-pointing.
The legacy @vue/cli command-line tool for scaffolding and serving Vue projects — deprecated in favour of create-vue + Vite, retained as reference for existing apps.
Daily-driver reference for webpack — CLI commands, dev server, loaders, plugins, code splitting, common config recipes.
Package-level reference for @biomejs/biome on npm — install, single-binary toolchain replacing prettier+eslint, Node support, and alternatives.
Package-level reference for the commander CLI framework on npm — install, version policy, TypeScript extras, and alternatives.
Package-level reference for concurrently on npm — install, output prefixing, kill-others, race-mode, and the npm-run-all2 comparison.
Package-level reference for cypress on npm — install size, binary caching, peer-dep landscape, playwright competition, and component-testing add-ons.
Package-level reference for the Day.js date library on npm — install, plugin model, version policy, and alternatives.
Package-level reference for debug on npm — namespace pattern, DEBUG env enable, browser vs Node, and production wrapping.
Package-level reference for the diff2html-cli renderer on npm — install, runtime support, peer-deps, and alternatives.
Package-level reference for the dotenv config loader on npm — install, native Node alternatives, dotenvx successor, and gotchas.
Package-level reference for esbuild on npm — bundle CLI, transform API, JS API, plugin system, and trade-offs vs Rollup, Webpack, and Vite.
Package-level reference for eslint on npm — install variants, flat config (v9) vs legacy .eslintrc, typescript-eslint, plugin ecosystem, and alternatives.
Package-level reference for form-data on npm — file uploads, streaming, headers, and the modern FormData web standard alternative.
Package-level reference for helmet on npm — default headers, CSP customization, per-route overrides, HSTS, and v7→v8 migration.
Package-level reference for http-server on npm — install, HTTPS, gzip, proxy mode, basic auth, and the serve comparison.
Package-level reference for jest on npm — install variants, transformer ecosystem, peer-dep landscape, vitest competition, and migration paths.
Package-level reference for lodash on npm — modular imports, ES2020+ replacements, lodash/fp, debounce/throttle, and the honest 'you might not need this' framing.
Package-level reference for node-fetch on npm — v2 (CJS) vs v3 (ESM), why Node 18+ built-in fetch obviates it, and migration paths.
Package-level reference for nodemon on npm — watch globs, exec patterns, config files, and how it compares to node --watch and tsx watch.
Package-level reference for npm-check-updates on npm — install, Node support, the ncu binary, doctor mode, workspaces, and where it fits next to npm outdated, taze, and bun update.
Package-level reference for npm-run-all2 on npm — install, glob-based script matching, run-s vs run-p, and migration from the unmaintained npm-run-all.
Package-level reference for openai on npm — Chat Completions, the Responses API, streaming, tool calls, structured outputs, embeddings, and the v4→v5 migration.
Package-level reference for oxc-transform on npm — Rust transformer from the oxc toolchain, TS/JSX support, current API maturity, and place in the ecosystem.
Package-level reference for @playwright/test and playwright on npm — install variants, browser-binary download, fixtures, traces, and alternatives.
Package-level reference for prettier on npm — install variants, v3 ESM-only switch, plugin model (Tailwind, Astro, etc.), Node support, and alternatives.
Package-level reference for prisma (CLI) and @prisma/client (runtime) on npm — install, generator, peer setup, Node and database support, and alternatives.
Package-level reference for qs on npm — nested objects, arrays, allowDots, prototype-pollution history, and URLSearchParams comparison.
Package-level reference for rimraf on npm — install, API, why it still exists in the Node fs.rm era, and migration paths.
Package-level reference for rolldown on npm — Rust rewrite of Rollup, API compatibility goals, current limitations, and the Vite migration path.
Package-level reference for rollup on npm — library bundling, multi-format output, plugin ecosystem, tree shaking, and the Rolldown migration.
Package-level reference for serve on npm — install, SPA fallback, auth, CORS, and when to reach for caddy or python -m http.server instead.
Package-level reference for ts-node on npm — TypeScript-aware REPL, transpile-only mode, ESM loader, and its tsx-driven decline.
Package-level reference for tsx on npm — enhanced Node.js runtime for TypeScript and ESM, watch mode, ts-node replacement, and Node loader integration.
Package-level reference for turbo on npm — install, pipelines, remote cache, filter syntax, and the Nx / pnpm-workspaces comparison.
Package-level reference for type-fest on npm — install (dev-only, pure types), TS version requirements, recursion limits, and alternatives.
Package-level reference for uuid on npm — v4 random, v5 namespace, v7 sortable, ESM-only since v9, and namespace pattern.
Package-level reference for the vercel CLI on npm — install, Node support, command surface, project linking model, and where it fits next to wrangler / netlify-cli.
Package-level reference for vite on npm — install variants, scaffold templates, plugin ecosystem under @vitejs/plugin-*, framework integrations, and alternatives.
Package-level reference for vitest on npm — install variants, vite peer-dep, UI and coverage add-ons, environments, and alternatives.
Reference for the legacy @vue/cli npm package — install, command surface, plugin model, and why create-vue + Vite is the recommended path for new projects.
Package-level reference for webpack on npm — loaders, plugins, code splitting, asset modules, module federation, and the slow migration toward Rspack and Vite.
Package-level reference for the wrangler CLI on npm — install, Node support, transitive dependency footprint, and platform-binding gotchas.
Package-level reference for ws on npm — client/server, broadcast, heartbeat, compression, and security pitfalls.
Package-level reference for yargs on npm — command builders, middleware, prototype-pollution history, and alternatives like commander.
Package-level reference for zod on npm — install variants, v4 breaking changes (looseObject, mini build), companion packages, and alternatives.
Package-level reference for black on PyPI — install variants, version policy, the [d] and [jupyter] extras, and how it relates to ruff format.
Package-level reference for Dagster on PyPI — install variants, the dagster-* plugin family, version policy, and alternatives.
Package-level reference for the jupyter meta-package on PyPI — install variants, what it pulls in, version policy, and alternatives.
Package-level reference for loguru on PyPI — install variants, version policy, and how it coexists with (does not replace) the stdlib logging module.
Package-level reference for mypy on PyPI — install variants, Python compat, the types-* stub-package ecosystem, and alternatives.
Package-level reference for packaging on PyPI — Version, SpecifierSet, Requirement, markers, install, alternatives.
Package-level reference for platformdirs on PyPI — install, version policy, alternatives, and the per-OS path conventions it returns.
Package-level reference for pluggy on PyPI — install, version policy, alternatives, and the hookspec/hookimpl model that powers pytest, tox, and devpi.
Package-level reference for pre-commit on PyPI — install variants, hook-pinning model, and how it composes with ruff, black, and mypy.
Package-level reference for Prefect on PyPI — install variants, version policy, cloud-vs-OSS extras, and alternatives.
Package-level reference for Pygments on PyPI — install, version policy, lexers, formatters, and the pygmentize CLI it ships.
Package-level reference for pytest on PyPI — install variants, version policy, the pytest-* plugin ecosystem, and alternatives.
Package-level reference for ruff on PyPI — install variants, fast-moving version policy, and how a single binary subsumes flake8, isort, pyupgrade, and black.
Package-level reference for trulens-eval on PyPI — install variants, the trulens umbrella rename, framework extras, and alternative evaluators.
Package-level reference for typing-extensions on PyPI — what's backported, install, version policy, and migration to stdlib.
Highlight source code from the command line — many lexers, many output formats.
Install, search, upgrade, pin, tap, bottle, and bundle packages with Homebrew on macOS: formulae vs casks, brew services, Brewfile-driven machine bootstrap, Apple-Silicon vs Intel prefixes, brew doctor, brew cleanup, and recovery recipes.
Importing, tagging, querying, and organizing a music library with beets — config, plugins, queries, and common workflows on Windows.
Install, upgrade, pin, and script software installs on Windows with the choco CLI, packages.config files, and custom sources.
Install dev tools without admin rights using Scoop — buckets, manifests, multi-version installs, and reproducible setups.
Configure Windows Terminal — settings.json structure, profiles for pwsh/cmd/wsl/ssh, keybindings, colour schemes, panes, and the wt.exe CLI.
Installing, upgrading, and managing packages with Windows Package Manager.
Running Linux tools from Windows and vice versa, file system access, and networking between WSL and Windows.
Downloading video and audio from YouTube and hundreds of other sites with yt-dlp — formats, playlists, subtitles, post-processing, and config.
Drive the CICS Master Terminal transaction — INQUIRE, SET, and PERFORM verbs for programs, tasks, files, connections, and region-level operations like NEWCOPY refresh and SNAP dumps.
Run SQL through SPUFI, drive Db2 with DSN subsystem commands, BIND packages and plans, schedule DSNTEP2 in JCL, query the SYSIBM catalog, and generate DCLGEN.
Migrate, recall, back up, and recover datasets across ML0/ML1/ML2 tiers with TSO H-commands and ARC operator commands; bulk-recall recipes, recall timing, and audit messages.
IBM DFSORT control statements and ICETOOL operators for sorting, merging, joining, and reshaping batch datasets on z/OS.
Define, copy, list, alter, and delete VSAM clusters and general datasets — the everyday utility for catalog and dataset lifecycle on z/OS.
Deep dive into the ISPF editor — primary commands, line commands, BNDS/CC/MM column edits, ISREDIT macro services, profile management, and recovery.
TSO commands for RACF user, group, dataset, and general-resource profile administration on z/OS.
Browse, filter, and act on JES2 spool from inside ISPF — find your job, read SYSOUT, cancel, purge, and issue operator commands.
Complete ISPF menu options, primary commands, line commands, edit profile, utilities, DSLIST, SDSF, TSO commands, RACF, and keyboard shortcuts.
The UNIX side of z/OS — OMVS, ISHELL, oedit, BPXBATCH, file tagging, zFS, and bridging shell scripts to MVS batch.
Open-source command-line bridge into z/OS — manage datasets, jobs, USS files, consoles, TSO, and Db2 from Mac/Linux/Windows over z/OSMF or RSE-API.
Automate Claude Code lifecycle events with shell hooks — PreToolUse, PostToolUse, UserPromptSubmit, Notification, Stop, SubagentStop, and PreCompact. Covers configuration, environment variables, JSON I/O, exit codes, and blocking examples.
Add, configure, and build Model Context Protocol (MCP) servers for Claude Code — HTTP, SSE, and stdio transports, management commands, permission rules, and a curated list of useful servers.
Install, configure, and use Claude Code — Anthropic's agentic CLI. Covers interactive mode, headless scripting, CLAUDE.md memory files, the project/user settings hierarchy, IDE integration, and authentication.
Complete settings.json schema for Claude Code — permission rules, tool allowlists/denylists, environment variables, hooks, MCP, statusline, model selection, and file precedence.
Author and load custom Claude Code skills — how skills are discovered, the SKILL.md schema, available-skills list, packaging, project-vs-user scope, plugin namespacing, and the difference from slash commands.
Complete reference for every built-in Claude Code slash command — session control, context management, configuration, tools, MCP, and authoring custom commands with arguments.
Customise the Claude Code statusline — settings.json keys, the JSON context passed to scripts, available variables (model, session id, cwd, branch, cost), and example scripts in bash, python, and Node.
Spawn isolated subagents with the Task tool — Plan, Explore, general-purpose, project-defined agents, isolation modes including worktrees, background runs, and orchestration patterns.
Advanced Claude Code workflows — effective CLAUDE.md authoring, custom skills, multi-agent patterns, headless scripting, cost control, keyboard shortcuts, prompt caching, and daily workflow techniques.
Control what Codex CLI can do — approval policies (untrusted, on-request, never), sandbox modes (read-only, workspace-write, danger-full-access), OS-native sandbox mechanics, and --full-auto.
Complete config.toml reference for Codex CLI — model selection, approval policies, sandbox modes, profiles, MCP server stubs, shell environment, notify hooks, and project trust levels.
Complete reference for codex exec — scripted invocation, stdin piping, JSON event streams, output formats, exit codes, timeouts, and automation patterns for CI, git hooks, and shell pipelines.
Add and configure Model Context Protocol (MCP) servers in Codex CLI — config.toml [mcp_servers.*] reference, the codex mcp subcommand, per-server tool approval modes, and the /mcp runtime command.
Install and use OpenAI's Codex CLI — the open-source agentic coding tool. Covers authentication, interactive mode, headless exec, ~/.codex/ layout, and AGENTS.md project memory.
Complete reference for every built-in Codex CLI slash command — session control, model switching, sandboxing, MCP management, and TUI utilities.
How Codex CLI supports delegating to child agents — the experimental /agent system, codex exec as a sub-agent pattern, MCP-mediated agent-to-agent calls, isolation boundaries, and orchestration patterns.
Advanced Codex CLI workflows — AGENTS.md authoring, profiles, experimental hooks, notify callbacks, non-interactive exec scripting, session resume and fork, and codex cloud.
Rust-based all-in-one linter and formatter for JS/TS/JSON/CSS/GraphQL. Single binary, single config, 10-100x faster than ESLint+Prettier.
Bun is a fast all-in-one JavaScript runtime, package manager, bundler, and test runner written in Zig — a drop-in replacement for Node.js and npm with built-in TypeScript and JSX support.
Build full-featured Node.js CLIs with positional arguments, typed options, subcommands, auto-generated help, lifecycle hooks, and a distributable bin in package.json.
Parse, format, manipulate, compare, and convert timezones for dates in JavaScript using Day.js — a 2 kB Moment-compatible alternative with a plugin-based architecture.
Deno is a secure, modern JavaScript and TypeScript runtime built on V8 with permission-based sandboxing, built-in TypeScript, a curated standard library on JSR, and a complete toolchain (fmt, lint, test, bench, compile).
Load configuration and secrets from .env files into process.env at startup, with multi-environment files, variable expansion, schema validation, and Node 20.6+ built-in --env-file alternatives.
Cross-browser end-to-end test runner from Microsoft with auto-waiting, role-based selectors, trace viewer, and codegen.
Schema-first ORM for Node.js with auto-generated typed client, declarative migrations, relations, transactions, and seeding — for PostgreSQL, MySQL, SQLite, MongoDB, and more.
TypeScript-first runtime validation library. Define schemas, validate inputs, infer static types — works at API boundaries, env config, forms, and tRPC.
Time-based job scheduler on Unix. Covers crontab syntax, user vs. system crontabs, environment quirks, logging, anacron, and the modern systemd timer alternative.
Practical Makefile patterns: targets, prerequisites, automatic variables, pattern rules, parallel builds, and a working lint/test/build/clean workflow for any project.
POSIX file permissions on Linux. Covers symbolic and octal chmod, ownership with chown, the meaning of r/w/x for files vs. directories, setuid/setgid/sticky bits, umask, ACLs, capabilities, and immutable attributes.
Comprehensive reference for qsv: count, headers, stats, moarstats, select, search, sort, dedup, frequency, join, sqlp, luau, apply, schema, validate, sample, split, MCP server, and more — with examples and outputs.
Catch quoting bugs, missing checks, and POSIX portability mistakes in shell scripts. Covers every flag, severity levels, inline directives, CI/pre-commit integration, and the most common rules.
Bram Moolenaar's modal editor. Covers modes, verb-noun grammar, text objects, registers, marks, windows, search-and-replace, quickfix, macros, configuration, and a high-value baseline .vimrc.
Pause, inspect, and step through Python programs with pdb. Covers breakpoint(), command reference, post-mortem debugging, conditional breakpoints, and enhanced alternatives like ipdb, pdbpp, and pudb.
Manage Python project dependencies, virtual environments, and package publishing with Poetry. Covers pyproject.toml, lockfiles, groups, and publishing to PyPI.
Run linters, formatters, and validators automatically on every git commit. Covers .pre-commit-config.yaml, essential hooks (ruff, mypy, check-yaml), autoupdate, and CI integration.
The canonical config file for modern Python projects — [project] metadata, [build-system] backends (setuptools, hatchling, pdm-backend, poetry-core, flit-core), [tool.*] sections, dynamic versioning, scripts, building, and publishing.
Build interactive web apps for data and ML in pure Python. Covers widgets, layout, session state, caching, multipage apps, and deployment patterns.
Go beyond list[int] and str | None. Covers Protocol, TypeVar bounds, ParamSpec, Concatenate, Self, Annotated, TypedDict with NotRequired/Required, TypeAlias, TypeGuard, TypeIs, cast, assert_type, and reveal_type.
Install packages and manage virtual environments blazingly fast with uv. Covers uv pip, uv venv, uv run, uv init, and how it compares to pip and poetry.
Split a TypeScript codebase into composite sub-projects, build them incrementally in dependency order with tsc --build, and integrate the result with bundlers, Turborepo, and Nx.
Drive the TypeScript compiler programmatically — parse SourceFiles, query the type checker, transform ASTs with the factory, and write codemods that scale across a monorepo.
Compare ts-node, tsx, Node 22.6+ --experimental-strip-types, Bun, and Deno for running .ts files directly; pick the right tool, configure watch mode, and avoid the classic ESM / type-strip pitfalls.
Sindre Sorhus's collection of essential TypeScript utility types — PartialDeep, ReadonlyDeep, SetOptional, RequireAtLeastOne, Merge, Tagged, JsonValue, Opaque, and dozens more — so you don't hand-roll them.
Cloudflare's official CLI for building, configuring, and deploying Workers, Pages, KV, R2, D1, Vectorize, Hyperdrive, Queues, Workflows, and Secrets.
Convert unified diffs and git diff output into styled HTML side-by-side or line-by-line diff views from the command line.
Trace, debug, evaluate, and monitor LLM applications with LangSmith. Covers tracing setup, datasets, evaluators, prompt hub, comparing runs, and CI integration.
Store and search vector embeddings with the Qdrant Python client. Covers collections, CRUD, filtered vector search, payload indexing, batch upsert, sparse/dense hybrid search, and integrations.
Measure and improve RAG pipeline quality with ragas. Covers faithfulness, answer relevancy, context precision, context recall, dataset format, LLM judges, and CI integration.
Evaluate and monitor LLM applications with TruLens. Covers the RAG triad, feedback functions, TruChain, TruLlama, custom evaluators, the dashboard, and CI integration.
Extract structured text from PDFs, Word docs, HTML, images, and more with the unstructured library. Covers partitioning, chunking, cleaning, metadata, and pipeline integrations.
Store, search, and manage vector embeddings with the Weaviate Python client. Covers collections, CRUD, vector/hybrid/BM25 search, multi-tenancy, generative search, and batch import.
Build, schedule, and observe data pipelines as software-defined assets with Dagster. Covers assets, jobs, schedules, sensors, resources, partitions, and the Dagster UI.
Build, schedule, and observe Python workflows with Prefect. Covers flows, tasks, retries, schedules, deployments, caching, concurrency, and Prefect Cloud.
The standard JavaScript/TypeScript linter. Covers flat config (v9), legacy .eslintrc, running, rules, plugins, TypeScript integration, VS Code, and pre-commit hooks.
Install Node.js on Windows, macOS, and Linux using winget, Homebrew, apt, nvm, Volta, or fnm. Covers version managers, LTS vs current, and verifying your install.
Complete npm reference — installing packages, scripts, workspaces, package.json anatomy, audit, publish, link, lockfiles, and registry configuration.
Run npm package binaries without global installs using npx. Covers resolution order, version pinning, --yes, --no-install, npm exec, scaffolders, and cache management.
Complete reference for the Node.js package manifest — name, version, scripts, dependencies, exports, workspaces, and the packageManager field for Corepack.
Fast, disk-efficient package manager using a content-addressable store and hard-links. Covers install, add, remove, scripts, dlx, exec, the pnpm store, and workspaces.
Opinionated code formatter for JS/TS/CSS/HTML/JSON/Markdown. Covers config options, .prettierignore, VS Code integration, ESLint compatibility, lint-staged, and CI usage.
Next-generation frontend build tool using native ES modules for near-instant dev server startup and Rollup for production bundles. Covers setup, config, HMR, env vars, assets, CSS, and plugins.
Vite-native unit test framework with a Jest-compatible API. Covers setup, writing tests, matchers, mocking, timers, async testing, coverage, and UI mode.
Yarn is a fast, deterministic package manager from Meta. Covers Yarn Classic (v1) vs Yarn Berry (v4), install, add, remove, workspaces, Plug'n'Play, and migration tips.
Complete pip reference covering installation, package management, requirements files, private registries, caching, offline installs, and reproducible builds.
Install the TypeScript compiler, run .ts files without a build step using ts-node or tsx, and compile projects with tsc. Covers tsc flags, watch mode, and project references.
Complete reference for tsconfig.json — compiler options for type checking, module resolution, output, paths, and JSX. Includes ready-to-use presets for Node 20, browser libraries, and Vite/React apps.
Format Python code consistently with black. Covers installation, configuration, editor integration, and how it compares to ruff format.
Run interactive Python notebooks with Jupyter. Covers JupyterLab setup, cell types, keyboard shortcuts, magic commands, nbconvert export, and common pitfalls.
Add structured, colorized logging to Python apps with loguru. Covers sinks, log levels, file rotation, retention, exception catching, and context binding.
Catch type errors before runtime with mypy. Covers strict mode, common error codes, type: ignore annotations, gradual typing, and pyproject.toml configuration.
Lint and format Python code with ruff — a single Rust-powered tool that replaces flake8, isort, and black. Covers configuration, rule selection, and CI usage.
navigation
actions
cheat sheet pages
