Learn local development
Practical guides for running projects on your own machine, grouped into topic hubs. A hub gives the overview of one subject and links its tools, guides, and glossary terms. A guide takes one task from start to finish, with the commands, the reasons behind them, and the limits. Where a guide ran a command or a loader itself, it names the version and says what it did not cover.
Topic hubs
- Topic hub
Ports and conflicts in local development
How ports work, which dev servers default to which port, what each does when its port is busy, and how to find and free a port on macOS, Linux, and Windows.
- Topic hub
Env files and secrets in local development
How environment variables and .env files work, what to commit, how to catch drift from .env.example, how to respond to a leak, and where a .env file stops.
- Topic hub
Running local dev processes: from terminal tabs to a process manager
Run a web app, API, and worker together: tabs, Procfiles, Compose, and process managers compared, with health checks, sidecars, and local HTTPS explained.
- Topic hub
MCP for coding agents: servers, config files, and tokens
How coding agents use MCP servers: where Cursor, Claude Code, Codex, VS Code, and others keep config, stdio versus HTTP, and how to keep tokens out of git.
All guides
- Guide
.env and .env.example checklist: what to commit, ignore, and rotate
A checklist for keeping .env, .env.example, and secrets in order: what to commit, ignore rules that work, drift checks, parser quirks, and leak response.
- Guide
Find what is using a port and free it
Find the process listening on a port and stop it safely on macOS, Linux, and Windows, with commands for each system, TERM before KILL, and fixes that last.
- Guide
localhost vs 127.0.0.1 vs 0.0.0.0
What localhost, 127.0.0.1, and 0.0.0.0 mean for a dev server, who can reach each bind address, and why your phone cannot open 127.0.0.1.
- Guide
MCP config file locations: where each coding agent reads its servers
Where Cursor, Claude Code, Claude Desktop, Codex, Windsurf, VS Code, Copilot CLI, and OpenCode read MCP config, with root keys, transports, and token safety.
- Guide
Procfile guide: syntax, process types, and running it locally
Learn the Procfile format, what web, worker, and release mean, a worked file for web, worker, and scheduler, and how Foreman, Honcho, Overmind, and Rig run it.
- Guide
Run multiple dev servers locally: which approach fits
Compare terminal tabs, tmux, concurrently, Procfile runners, Docker Compose, and Rig for running a web app, API, and worker together, with a trade-off table.
Hubs and guides
Start with a hub when a subject is new to you: it explains how the pieces fit, suggests a reading order, and states what the subject cannot do for you. Start with a guide when you already know the task. Each guide shows its reading time, its sources with the date each was checked, and the date of its last substantive update. The tools, port references, and glossary cover the same subjects in smaller pieces.
How guides are checked
Claims about other tools come from their official documentation, and claims about Rig come from Rig’s source code. Hubs summarise a subject and link to the guides, which carry the evidence.
How guides are kept current
Every guide and hub records the date of its last substantive update. A draft is not published and is not listed here. A page found to be out of date is marked as needing an update and is re-checked.
Related
Section links
- Ports and conflicts in local development
- Env files and secrets in local development
- Running local dev processes: from terminal tabs to a process manager
- MCP for coding agents: servers, config files, and tokens
- .env and .env.example checklist: what to commit, ignore, and rotate
- Find what is using a port and free it
- localhost vs 127.0.0.1 vs 0.0.0.0
- MCP config file locations: where each coding agent reads its servers
- Procfile guide: syntax, process types, and running it locally
- Run multiple dev servers locally: which approach fits