Resources 6 min read

Vibe Coding Glossary: MCP, AI Agents, Context Window, Prompts — Simply Explained

The essential glossary of terms for AI-assisted development. Clear, accessible definitions for MCP, coding agents, context windows, session compaction, tokens, and AI Context.

Publicat de fanTask Engineering
Model Context Protocol (MCP)

The Language of the New Era in Software Development

The field of artificial intelligence is evolving at a breakneck pace, bringing with it a flood of acronyms and technical terms that can feel intimidating to anyone setting out to build their first project.

Whether you're listening to a tech podcast, reading an online tutorial, or launching an AI-assisted development environment, you will constantly encounter concepts like "Model Context Protocol", "context window", "compaction", or "autonomous agents".

This practical glossary translates technical jargon into simple, clear explanations grounded in the everyday reality of software development. Keep it handy as a quick reference whenever you run into an unfamiliar term.

1. Vibe Coding

Definition: A modern software development paradigm in which a person builds applications by describing in natural language what they want to achieve, delegating writing, testing, and organizing source code to an AI agent.

The term was popularized in early 2025 by AI researcher Andrej Karpathy to describe the state where human developers no longer concentrate on painstaking syntax or typing details, but on the overall "vibe" of the product — product direction, user flows, and expected behavior.

2. AI Coding Agent (Coding Agent)

Definition: A system powered by large language models (LLMs) that is not confined to generating text in a chat window, but possesses the autonomous capability to act upon your local development environment: reading workspace files, creating new modules, editing existing code, running terminal commands, and verifying runtime errors.

Popular examples: Claude Code (Anthropic), Google Antigravity, Cursor Agent Mode, GitHub Copilot Workspace.

The difference from a chatbot: A chatbot is a passive advisor (it displays suggestions on screen, but you have to implement them). An agent is an active collaborator (it directly executes technical tasks inside your files).

3. Prompt (and Prompt Engineering)

Definition: The text instruction, question, or task description that you send to an artificial intelligence model to trigger a specific response or action.

Prompt Engineering: The practice and technique of crafting instructions that are precise, well-structured, and free of ambiguity, providing necessary background context, clear examples, and firm constraints (for example: "Write only the TypeScript function without extra explanation, and ensure it handles the unauthenticated user edge case").

4. Context Window

Definition: The active working memory of an artificial intelligence model during an interaction — the maximum volume of information (text, code, previous commands) that the model can process simultaneously in a single turn.

Think of the context window like the surface of a desk: a small desk holds only a few pages; an enormous desk lets you lay out entire folders. But regardless of desk size, the physical surface remains finite. When you build software involving dozens of files, build error logs, and lengthy conversations, active working memory inevitably fills up.

5. Session Compaction

Definition: The automated mechanism by which AI coding environments summarize or prune earlier portions of a conversation when session history approaches the context window's ceiling.

Why it matters: Compaction is the reason an AI suddenly seems to "forget" rules agreed upon an hour earlier. During aggressive summarization passes, nuanced details — such as a file naming convention, a security edge-case guard, or a subtle browser quirk — are the very first details lost.

6. Token

Definition: The fundamental atomic unit by which large language models read, process, and measure text. A token is not necessarily a single word; it can be a short word, part of a longer word, a punctuation mark, or a sequence of whitespace characters.

As a general rule of thumb, 1,000 tokens represent roughly 750 English words. Model context limits, compute costs, and API pricing are universally calculated based on the count of processed input and output tokens.

7. Model Context Protocol (MCP)

Definition: An open communication standard originally developed by Anthropic and rapidly embraced by the broader technology industry, enabling AI models and autonomous agents to securely and consistently connect to external tools, databases, local file trees, and third-party software services.

Before MCP, every AI assistant required fragile, bespoke integrations for each external tool. Under MCP, any third-party tool (such as a Postgres database, a GitHub repository, or a task tracking platform) can expose an MCP server with a clear manifest of callable tools and resources that any compatible agent can discover and invoke automatically.

A simple analogy: MCP is to AI agents what the USB standard was for computers. Instead of needing unique proprietary ports for keyboards, mice, and printers, you plug into one universal socket through which all devices communicate seamlessly.

8. AI Context (Persistent Context)

Definition: A durable ledger of architectural guidelines, coding conventions, project constraints, and discovered technical gotchas, maintained outside of the agent's volatile chat history, which every connected assistant is guaranteed to inspect before initiating work.

Unlike a prompt preamble manually pasted at the start of each new chat or bloated local configuration files that clutter the token window, persistent AI Context is pulled on demand by the agent at the kickoff of any task, ensuring unbroken continuity even when you switch tools or launch a fresh terminal session.

How All These Concepts Connect in the Real World

When you practice vibe coding at a professional level, you aren't simply dealing with isolated technologies. You are coordinating a unified ecosystem:

You issue structured prompts to an AI coding agent. The agent inspects your codebase, but to avoid being blinded by the finite limits of the context window or the data loss of session compaction, it connects via the Model Context Protocol (MCP) to a central source of truth. From there, it retrieves persistent AI Context and synchronizes its work against an active backlog.

This is precisely what fanTask provides: a native collaboration space where human creators and AI agents work together against a shared backlog, keeping software stable, well-architected, and free from long-term amnesia.

Persistent Memory for AI Agents

Ready to give your AI coding agents permanent memory?

fanTask provides persistent AI context and searchable task history over Model Context Protocol. The free tier includes 1 project and 3 members.