@thesimonharms/code-shot

MCP server that renders source code as beautiful images. Perfect for AI agents to show code visually to humans on mobile devices, or for sharing syntax-highlighted snippets.

Example

Generated from this TypeScript snippet with theme: github-dark and title: greet.ts:

function greet(name: string): string {
  const message = `Hello, ${name}!`;
  return message;
}

console.log(greet('world'));

Tools

render_code

Render source code as SVG or PNG with full syntax highlighting.

Param	Type	Default	Description
code	string	required	Source code to render
language	string	auto-detect	Language (ts, rust, py, go, js, and 40+ more)
theme	string	github-dark	Color theme (nord, dracula, catppuccin, one-dark-pro, etc.)
title	string	—	Window title bar text (e.g. filename)
show_line_numbers	boolean	true	Line number gutter
font_size	number	14	Font size in px
output_format	svg|png	svg	SVG is crisp & copyable; PNG is raster
width	number	auto	Code area width in characters
padding	number	16	Padding in px

render_diff

Render a git unified diff with color-coded additions/deletions and language-aware syntax highlighting.

Param	Type	Default	Description
diff	string	required	Unified diff content (git diff output)
highlight_language	string	auto-detect	Language for highlighting within hunks. Auto-detected from diff --git header (e.g. file.ts → TypeScript). Set to "diff" for plain diff highlighting.
...	—	—	Same options as render_code

Diff lines are highlighted with:

• @@ hunk headers → blue background
• + additions → green background (#1b4520 dark / #dafbe1 light)
• - deletions → red background (#4f1818 dark / #ffebe9 light)

Syntax highlighting is applied per-hunk in the detected language — not just plain diff markup.

Themes

18 bundled themes:

Dark	Light
github-dark	github-light
nord	one-light
one-dark-pro	material-theme-lighter
dracula	min-light
dracula-soft	solarized-light
catppuccin-mocha	catppuccin-latte
material-theme	vitesse-light
min-dark	—
solarized-dark	—
vitesse-dark	—

Test Suite

46 tests across two runners:

npm test    # Build → MCP integration tests (cobasaja) → Unit tests (node --test)

• 5 MCP integration tests (tests/code-shot.test.ts) — tool discovery, rendering, error cases
• 37 unit tests (tests/*.node-test.ts) — renderSvg structure, diffToLines parsing, guessLanguage heuristics

Usage with Hermes

Add to ~/.hermes/config.yaml:

mcp_servers:
  code-shot:
    command: "npx"
    args: ["-y", "@thesimonharms/code-shot"]

Or from local build:

mcp_servers:
  code-shot:
    command: "node"
    args: ["/path/to/code-shot/dist/index.js"]

Configuration

Set defaults via ~/.code-shotrc (JSON):

{
  "theme": "nord",
  "show_line_numbers": true,
  "font_size": 14,
  "padding": 16
}

Also checked (in order): ~/.code-shotrc > ~/.code-shotrc.json > ~/.config/code-shot/config.json.

Tool call arguments override config file values.

Usage with Claude Code / Cursor

{
  "mcpServers": {
    "code-shot": {
      "command": "node",
      "args": ["/path/to/code-shot/dist/index.js"]
    }
  }
}

Development

npm install
npm run build    # tsc
npm test        # build + cobasaja + node --test

How it works

1. Shiki tokenizes the code with full syntax highlighting (grammars for 40+ languages)
2. SVG renderer builds a pixel-perfect SVG with monospace positioning, window chrome, line numbers, and diff markers
3. Optional PNG via @resvg/resvg-js for platforms that don't support SVG natively
4. Language auto-detection via shebang parsing and code heuristics (18 language patterns)
5. Diff language detection from diff --git a/file.ext b/file.ext headers

No browser, no DOM, no headless Chromium — pure math-based SVG generation.

License

MIT