poster-render

Node.js CLI for rendering poster slides as 1080×1350px PNGs. Accepts structured JSON or Markdown, outputs one PNG per slide.

MIT licensed. Issues and PRs welcome.

Install

pnpm install

Requires Node.js 22+ and native canvas dependencies:

• macOS: brew install pkg-config cairo pango libpng jpeg giflib librsvg pixman
• Ubuntu/Debian: sudo apt-get install build-essential libcairo2-dev libpango1.0-dev libjpeg-dev libgif-dev librsvg2-dev

Quick start

poster-render content.json --template bold --output ./slides

Or with Markdown input:

poster-render deck.md --template minimal --output ./slides

Agent pipeline (JSON result on stdout):

poster-render deck.md --template technical --json

Templates

Template	Feel	Cover	Content
minimal	Editorial, thought leadership
bold	Campaign, product launches
technical	Engineering blog, devtools

Live preview with auto-reload:

pnpm preview:minimal   # http://localhost:3456
pnpm preview:bold
pnpm preview:technical

CLI options

Flag	Values	Description
--template <name>	minimal | bold | technical	Visual template (required for HTML path)
--output <dir>	any path	Output directory (default: ./output)
--json	flag	Write {"slides":[…],"count":N,"template":"…","output":"…"} to stdout
--typography <name>	sm | md | lg | golden-ratio	Override typography scale
--no-cover-kicker	flag	Hide the auto-generated word count kicker

Helpful scripts

pnpm sample            # render examples/sample-content.json → ./output-sample
pnpm preview:minimal   # live preview at localhost:3456
pnpm preview:bold
pnpm preview:technical
pnpm test
pnpm lint

content.json schema

{
  "cover": {
    "title": "Slide title",
    "subtitle": "Optional subtitle",
    "kicker": "Optional top line; auto-generated by default",
    "showKicker": true,
    "coverImage": "path/to/image.jpg",
    "coverStyle": "card"                 // "card" | "fluid" | "inset"
  },
  "sections": [
    {
      "headline": "Section heading",
      "body": "Body text.\n\nSupports multiple paragraphs.",
      "image": "path/to/image.jpg",      // optional
      "imageAspect": "16/9",             // "16/9" | "4/3" | "1/1" | "free"
      "imagePosition": "top"             // "top" | "center" | "bottom"
    }
  ],
  "cta": "Closing call-to-action text",
  "tags": "#hashtag1 #hashtag2"
}

Sections are auto-paginated — if a section body is too tall for one slide it splits automatically. Sections with images start a new slide.

The cover kicker is auto-generated as 全文 {字数}字 · {阅读时间}分钟阅读. Disable with cover.showKicker: false.

Section body syntax

Inline code and fenced code blocks are supported:

"body": "Use `const` for immutable bindings.\n\n```js\nconst x = 1;\n```"

Supported languages: js, ts, python, rust, go, java, c, cpp, html, css, json, bash, sql.

Custom fonts (optional)

Place .ttf or .otf files in ./fonts/. Files are auto-registered by name substring:

File name contains	Family
geistmono	mono
geist	sans
helvetica	sans / Helvetica Neue
georgia	serif / Georgia
menlo	mono / Menlo

For CJK text, install a system font: PingFang SC, Hiragino Sans GB, or Noto Sans CJK SC.

Contributing

Small patches preferred. Run pnpm test and pnpm lint before sending a PR.

License

MIT — see LICENSE.