fountain-preview.nvim

A Neovim plugin that provides a live HTML preview of Fountain screenplays in your browser, with real-time updates and synchronized scrolling as you edit.

Features

• Live preview — renders your screenplay in a browser as you type
• Real-time sync — browser scrolls to follow your cursor position in the editor
• Full Fountain support — title pages, scene headings, action, dialogue, parentheticals, transitions, dual-column dialogue, centered text, sections, page breaks, and inline formatting
• Auto-opens browser — optionally launches the browser when preview starts
• No external dependencies — pure Lua using Neovim's built-in APIs and libuv

Requirements

• Neovim 0.7+
• A web browser

Installation

Using lazy.nvim:

{
  "pypp/fountain-preview.nvim",
}

Using packer.nvim:

use "pypp/fountain-preview.nvim"

Usage

Open a .fountain file and run:

:FountainPreview

The browser will open at http://localhost:8765 with a live preview. Edit your screenplay and the preview updates automatically.

Commands

Command	Description
:FountainPreview	Start the preview server
:FountainPreview [port]	Start on a specific port
:FountainPreview stop	Stop the preview server
:FountainPreview update	Force an immediate re-render

Configuration

Pass options to setup() to override defaults:

require("fountain_preview").setup({
  port = 8765,           -- Port for the preview server
  auto_open = true,      -- Auto-open browser on start
  debounce_ms = 300,     -- Delay (ms) before re-rendering after edits
  update_events = {      -- Neovim events that trigger a preview update
    "TextChanged",
    "TextChangedI",
    "BufWritePost",
  },
})

Fountain Format Support

Element	Syntax
Scene heading	INT. LOCATION - DAY or .SCENE TEXT
Action	Plain paragraph
Character	CHARACTER NAME (all caps)
Dialogue	Line following a character cue
Parenthetical	(beat)
Transition	CUT TO: or uppercase ending in TO:
Dual dialogue	Append ^ to second character name
Centered text	> TEXT <
Page break	=====
Section	# Heading, ## Sub, etc.
Bold	**text**
Italic	*text*
Underline	_text_

How It Works

1. A lightweight HTTP server starts on the configured port using Neovim's libuv event loop
2. The browser connects and keeps an open Server-Sent Events stream
3. On each edit, the Fountain buffer is parsed to HTML and pushed to the browser via SSE
4. Cursor movement sends scroll-only events so the browser viewport stays in sync with the editor