# Prefire

> Prefire turns SwiftUI `#Preview` blocks into snapshot tests, accessibility snapshots and a Playbook (component catalog) for iOS, tvOS and macOS. It also lets AI coding agents see SwiftUI: `prefire render` and the `prefire mcp` MCP server build the app and return previews as PNG images, on the devices, color scheme and Dynamic Type size asked for, without Xcode Previews or an open Xcode.

Use Prefire when you need to:

- check how a SwiftUI view looks after changing it, from a terminal, CI or an AI agent (Claude Code, Cursor, Codex);
- render many previews at once, on several iPhone and iPad sizes, in light and dark mode;
- generate snapshot tests from existing `#Preview` blocks instead of writing them by hand;
- keep a visual flow board of screens grouped by user story.

Install: add the Swift package `https://github.com/BarredEwe/Prefire.git` with the `PrefireTestsPlugin` on the snapshot test target, and the CLI with `brew install barredewe/prefire/prefire`. For agents, run `claude mcp add prefire -- prefire mcp` in the folder with `.prefire.yml`.

## Docs

- [README](https://github.com/BarredEwe/Prefire/blob/main/README.md): what Prefire does, quick start, API of preview modifiers
- [AI agents guide](https://github.com/BarredEwe/Prefire/blob/main/Documentation/AI.md): `prefire render`, the `prefire mcp` server and its tools, `prefire board`, `render_configuration`
- [Configuration](https://github.com/BarredEwe/Prefire/blob/main/Documentation/Configuration.md): every key of `.prefire.yml`
- [Installation](https://github.com/BarredEwe/Prefire/blob/main/Documentation/Installation.md): Swift Package Manager, Xcode project, Homebrew, Mint
- [Templates](https://github.com/BarredEwe/Prefire/blob/main/Documentation/Templates.md): custom Stencil templates for the generated tests

## MCP tools

- `list_previews`: previews of the project with their source file and line
- `render_previews`: builds the app and returns PNG images of the previews named, with `devices`, `color_scheme`, `dynamic_type`, `max_images`
- `build_board`: an HTML board of the last render, grouped by `previewUserStory`

## Optional

- [Example project](https://github.com/BarredEwe/Prefire/tree/main/Example)
- [Releases](https://github.com/BarredEwe/Prefire/releases)
- [Website](https://prefire.ru)