free · no signup · 56 entries and growing
The Vibe Coder's Dictionary
Your AI speaks fluent developer. You don't have to. But understanding its words is how you stay in charge, so each entry explains one term the way a friend would, shows why your agent brought it up, and teaches you how to say it like a dev.
AI & agents
Context windows, tokens, MCP, hooks: the machinery behind your agent.
Tokens vs credits: what you are actually paying for when you vibe code
Tokens are the raw unit AI models bill by; credits are the wrapper currency your coding tool converts them into, at an exchange rate that isn't fixed.
Usage limits in Claude Code (windows, caps, and how not to hit them)
Usage limits are the two stacked caps on your Claude plan, a five-hour rolling session window and a separate weekly ceiling, both measured in tokens rather than message count, that block further use until they reset.
What are Claude skills? (reusable instructions your agent loads on demand)
A Claude skill is a folder with a SKILL.md file of instructions, and optionally scripts or templates, that Claude Code reads and follows only when your request matches what the skill is meant to do, instead of every procedure sitting loaded all the time.
What are hooks in Claude Code?
A hook is a command you wire to a specific moment in Claude Code's process (like after a file edit or when it finishes a turn) so it runs automatically without you asking.
What are subagents in Claude Code?
A subagent is a separate Claude instance your coding agent spawns to handle one bounded task in its own context window, then hands back just the result.
What is /compact in Claude Code? (and why it can lose your context)
/compact is Claude Code rewriting your conversation into a shorter summary when the context window is filling up, and summaries always drop detail.
What is a context window? Why your AI forgets what you were doing
A context window is the fixed amount of conversation and code your AI can actually see at once. Once it's full, older stuff quietly falls off.
What is a system prompt? (and why the same AI feels different in every tool)
A system prompt is the set of instructions an app hands the AI before you type your first word, and it's why the same underlying model can feel like a different assistant in every tool you use it in.
What is agentic coding? (and how it differs from vibe coding)
Agentic coding is when an AI works through a task in a loop, reading your files, taking real actions, checking the results, and adjusting, instead of answering your prompt once and stopping.
What is AI slop? (correct syntax, wrong everything)
AI slop is code that looks finished and correct, clean syntax, sensible structure, but doesn't actually do what it's supposed to once you test it.
What is an AI hallucination in code? When your agent invents things
An AI hallucination in code is when your agent confidently writes a function, library, or setting that simply doesn't exist.
What is MCP (Model Context Protocol)? And do you actually need it?
MCP is the open standard that lets your AI agent plug into outside tools and data (like GitHub, Notion, or a database) without custom code for every single one.
What is Plan Mode in Claude Code? (and what it does not protect you from)
Plan Mode blocks Claude Code's file-editing tools until you approve a plan, but a shell-command prompt you approve during that time still runs for real.
What is prompt fatigue? (when fixing one bug takes fourteen prompts)
Prompt fatigue is the exhausting spiral where you send prompt after prompt trying to fix one bug, and each fix patches the last patch instead of closing in on the actual cause.
What is RAG? (how your AI looks things up before answering)
RAG (Retrieval-Augmented Generation) is when your AI searches a knowledge base for relevant information first, then writes its answer using what it found, instead of answering purely from memory.
What is the 70% wall? (why the last 30% of your app is the hard part)
The 70% wall is the point in building an app, usually hour four to eight of a first project, where sending another prompt stops closing the gap between mostly working and actually working.
Git & versions
Commits, branches, worktrees: how your project remembers.
Git clone vs pull vs fetch: which one do you need?
Git clone downloads a full copy of a repository the first time you get it, git fetch checks the remote for new commits without touching your files, and git pull fetches those commits and merges them straight into your current branch.
How do you undo in vibe coding? Rollback, revert and version history
Rollback, revert, and version history are different ways of getting your project back to a state that worked before the last change broke it.
What is a git worktree? (and why your coding agent created one)
A git worktree is a separate folder checked out from your same project history, letting your AI agent work on one thing there while your main session keeps working untouched elsewhere.
What is a merge conflict? (two changes, same lines, someone has to choose)
A merge conflict is what git shows you when two sets of changes edit the exact same lines of a file in different ways, and it needs a human to pick which version survives.
What is a pull request? (proposing changes instead of pushing them)
A pull request is a request to merge one branch of code into another, packaged with a diff and a review step, instead of pushing changes straight onto the main branch.
What is Git? Commits, branches and pushes, explained for vibe coders
Git is a save-and-rewind system that records labeled snapshots of your project (commits), lets you branch off to try things safely, and pushes those snapshots to a remote copy like GitHub.
Terminal
The black window, decoded.
Permission denied: what your terminal is actually saying (and the fix you should never copy-paste)
"Permission denied" is your operating system telling you that your user account isn't allowed to do what you just asked, not that something is broken.
What do npm install, node_modules and package.json actually do?
npm install reads package.json's list of dependencies and downloads the actual code for each one into the node_modules folder.
What is a linter? (the spell-checker for code)
A linter is a tool that reads your code without running it and flags patterns that are likely bugs or style problems, the same way a spell-checker flags a typo before you hit send.
What is PATH? (why your terminal says command not found)
PATH is an environment variable holding an ordered list of folders your operating system searches every time you type a command name, so a missing folder there is exactly why your terminal says command not found.
Files & project
What all those files in your repo actually are.
What are .cursorrules and .cursorignore? (steering Cursor)
A .cursorrules file used to be Cursor's one file for telling its AI how to work in your project, now replaced by Project Rules (.mdc files in .cursor/rules), while .cursorignore is a separate file that tells Cursor which files to keep out of the AI's context (mostly).
What is .gitignore? (the list of things git pretends not to see)
A .gitignore file is a plain-text list of file and folder patterns that tells git which things to never track, stage, or commit, even when they sit right there in your project folder.
What is a repository? (it's not just a folder)
A repository is your project's folder plus the complete history git has recorded for it, and it can live only on your computer, only on a host like GitHub, or as two synced copies of the same thing.
What is an environment variable? (and why your app has a .env file)
An environment variable is a named value your app reads from its surroundings at runtime, instead of having it hardcoded, so secrets and settings can change without touching a line of code.
What is CLAUDE.md? (your agent's memory file)
CLAUDE.md is a plain markdown file in your project that Claude Code reads automatically at the start of every session, so instructions you'd otherwise repeat every time only need to be written once.
What is package.json? (your project's ID card)
package.json is the file at the root of a JavaScript project that names it, lists every package it depends on, and defines the shortcut commands, like npm run dev, that you and your agent both use to work on it.
Web & deploys
From localhost to the real internet.
Custom domains and DNS (why your site takes hours to go live)
DNS is the address book that tells the internet which server your domain name actually points to, and the wait after you set it up is computers around the world clearing their old cached answer, not your domain "travelling" anywhere.
Localhost vs production: why your app works on your machine but breaks online
Localhost is your app running privately on your own machine; production is the live version everyone else can actually use, and the two don't always behave the same.
npm run dev vs npm run build: why your agent runs one to code and the other to ship
npm run dev starts a local server that reloads instantly as you edit, while npm run build compiles a minified, optimized version of your app for production, and running one is never a substitute for the other.
SSR vs SSG: where your pages get built, and why it matters
SSR, SSG, and ISR are three different moments when your page's HTML actually gets built, on every visit, once at deploy time, or once and then quietly refreshed, and each one trades speed against freshness differently.
What does deploying actually mean? (from your laptop to the internet)
Deploying is the step where your app stops running only on your own machine and starts running on a server that stays on all the time, at an address anyone can visit.
What is a CDN? (why your site is fast on the other side of the world)
A CDN is a network of servers placed in cities all over the world that hold cached copies of your site's files, so a visitor's browser downloads them from a nearby server instead of the one machine where your app actually lives.
What is a rate limit? (why the API told you to slow down)
A rate limit is a cap an external service puts on how many requests you can send it per minute, and going over it gets you a 429 error instead of your data.
What is a webhook, explained simply?
A webhook is a URL you give another service so it can push you a message the instant something happens, instead of you asking over and over.
What is an API endpoint? (the doors your app knocks on)
An API endpoint is a specific URL that, combined with an HTTP method, tells a server to do one exact thing, like fetch a user or create a payment.
What is CI/CD? (why your site updates itself after a push)
CI/CD is the automated pipeline that builds and tests your code the moment you push it, then ships it live on its own if everything passes, no one has to click deploy by hand.
What is CORS and why is it blocking your app?
CORS is the browser's rule that blocks your frontend's JavaScript from reading a response from a different origin unless the server explicitly says it's allowed.
What is hosting? (where your app actually lives)
Hosting is the always-on computer, somewhere out on the internet, that keeps your app reachable at a URL even after you've closed your laptop.
Databases
Where your data lives, and how to keep it yours.
What is a database migration? (changing the shape of your data, safely)
A database migration is a small, version-controlled file that describes one specific change to your database's structure, applied in order so every environment ends up with the exact same schema.
What is a database schema? (the floor plan of your data)
A database schema is the blueprint of your data: which tables exist, what columns each one has, and how they connect to each other, agreed on before any real row gets stored.
What is RLS (Row Level Security)? The setting that keeps your Supabase data private
Row Level Security is the Postgres rule set that decides, row by row, who can read or write data, and in Supabase it's the only thing standing between your public anon key and your entire database.
What is seeding a database? (fake data, real reasons)
Seed data is a starter set of records, like sample users or products, that a script writes into your empty database automatically, so there's something to look at and test before real users ever show up.
What is Supabase? (the database your AI keeps choosing)
Supabase is a hosted Postgres database bundled with authentication, instant APIs, file storage and realtime updates, which is why most AI app builders wire it up as your backend by default.
Where does your app actually store data? Databases, explained
A database is where your app's information actually lives after you close the tab, organized into tables so it can be found, trusted, and shared by many users at once.
Security
Keys, secrets, and the mistakes that leak them.
API key vs secret vs token: what is the difference?
A secret is any credential you keep hidden; an API key is a long-lived secret identifying your app, and a token is a short-lived secret identifying a user or session.
What is a JWT? (the wristband your app checks at the door)
A JWT is a signed token that proves who a user is, so your server can trust it on every request without looking anything up in a database.
What is OAuth? (how Sign in with Google actually works)
OAuth is a protocol that lets you grant one app limited access to your account on another service (Google, GitHub, etc.) without ever handing that app your password.
What is prompt injection? (when someone else talks to your AI)
Prompt injection is malicious or misleading text hidden inside a webpage, email, file, or issue that your AI agent reads and treats as an instruction, instead of as content to summarize or check.
What is SQL injection? (and why input validation is non-negotiable)
SQL injection is a security flaw where text typed into a form field gets inserted straight into a database query, letting an attacker rewrite what that query actually does.
Your API key is exposed: what happens, what to do, how to prevent it
An exposed API key is a secret that leaked somewhere public, and from that moment it works for whoever finds it, not just you.
Want these explanations about your own project?
That's what the Glimfly app does: it watches your agent work and explains your sessions live. Join the waitlist to get it first.