A spell for your stack · free · no account
Cast a spell your agent will follow
Stop rewriting AGENTS.md, Cursor rules, and system prompts by hand. Pick a stack, set the tone, and copy a file your agent can follow. Or start from a preset.
Generator
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How it works
01
Choose the file and the stack
Next.js, FastAPI, Unity, Godot, and the rest do not share the same rules. Pick the file you need and the stack you are actually in.
02
Set the terms of the spell
Testing, strictness, comments, error handling, and whether the agent stays on the task or notes one follow-up.
03
Copy it into the repo
Copy or download. Drop the file in the repo, or paste the system prompt into the agent. Nothing is uploaded.
Ready-made spells
All 320 recipesAGENTS.md
AGENTS.md for Next.js
App Router and Server Components.
.cursor/rules/project.mdc
Cursor rules for React
function components and hooks.
CLAUDE.md
CLAUDE.md for FastAPI
FastAPI, Pydantic v2, and pytest.
system-prompt.md
system prompt for Rust
Cargo, clippy, and Result-first Rust.
AGENTS.md
AGENTS.md for Unity
Unity C# and the Test Framework.
.cursor/rules/project.mdc
Cursor rules for Godot
Godot 4, GDScript, and signals.
Want the featured Next.js file with the knobs already set? Open it in the generator.
Questions
What does VibeSpell generate?
Four instruction files: a Cursor rule (`.cursor/rules` or `.cursorrules`), an `AGENTS.md`, a `CLAUDE.md`, and a generic system prompt. Each one is filled in for the stack you pick.
Does it upload my code?
No. The file is assembled in your browser from the options on the page. VibeSpell never sees your repository.
Which file should I start with?
Use AGENTS.md if more than one agent touches the repo. Use Cursor rules if you only work in Cursor. Use CLAUDE.md for Claude Code. Use the system prompt when the agent does not read a file from the repo.
Is it free?
Yes. There is no account. If a sponsor credit or a recommended tool shows up later, it is labeled, and recommended links are marked as sponsored.
Will Cursor, Claude Code, and Codex read these?
Cursor reads `.cursor/rules` and AGENTS.md. Claude Code reads CLAUDE.md. Codex and a growing set of agents read AGENTS.md. The system prompt is for products where you paste instructions yourself.
New stacks, not a drip campaign
A short note when a new stack or spell ships. No product newsletter. Until a provider is connected, an address you submit is checked and then discarded.