darshana

Crawl any web app and generate a labeled PDF, HTML viewer, or image set for design review.

Darśana — Sanskrit for "the act of seeing clearly."

Try it now

npx @opendatalabs/darshana --url https://vana.org --public --max-pages 10

Output lands in ./darshana-output/ — a PDF and a self-contained HTML viewer with sidebar nav, filters, and keyboard navigation.

For a private app, darshana opens a browser so you can log in, then saves the session:

npx @opendatalabs/darshana --url https://app.vana.org
# A browser opens → log in → press Enter → capture begins

Install

npm install -g @opendatalabs/darshana

Chromium is installed automatically. Or skip the install entirely and use npx @opendatalabs/darshana.

Linux only: if Chromium fails to launch, you may be missing system libraries. Fix with:

sudo npx playwright install chromium --with-deps

CLI reference

darshana --url <url> [options]         # zero-config
darshana --config <path> [options]     # file-based (CLI args override config)

--url <url>              Base URL to crawl
--config <path>          Path to a JSON config file
--title <string>         Review title (default: hostname)
--start <path>           Starting path (default: /)
--public                 Skip auth — use for public sites
--auth-storage <path>    Where to save/load the session (default: ./darshana-output/auth.json)
--auth-script <path>     Headless login script (see Auth below)
--themes <list>          Comma-separated: system,dark,light (default: system)
--viewports <list>       Comma-separated: desktop,mobile (default: desktop)
--max-depth <n>          BFS depth limit (default: 5)
--max-pages <n>          Page cap (default: 100)
--delay <ms>             Wait after page load before capture (default: 400)
--outputs <list>         Comma-separated: pdf,html,images (default: pdf,html)
--output-dir <path>      Output directory (default: ./darshana-output)
--include <regex>        Crawl only paths matching this pattern (repeatable)
--exclude <regex>        Skip paths matching this pattern (repeatable)
--dry-run                Discover URLs without capturing
--route <path>           Capture a single route only
--auth-only              Save auth session and exit

Config file

For complex projects, a JSON config gives you per-route sampling rules and capture overrides. CLI args always override config file values.

{
  "title": "My App",
  "url": "https://myapp.example.com",
  "start": "/dashboard",
  "public": false,
  "authStorage": "./auth.json",
  "authScript": "./auth.mjs",
  "crawl": {
    "include": ["^/dashboard"],
    "exclude": ["logout", "delete"],
    "maxDepth": 3,
    "maxPages": 50,
    "routes": [
      { "pattern": "/dashboard/records/:id", "sample": 1, "follow": false },
      { "pattern": "/dashboard/runs/:id",    "sample": 2, "follow": false },
      { "pattern": "/dashboard/**",          "follow": true }
    ]
  },
  "capture": {
    "themes": ["dark", "light"],
    "viewports": ["desktop", "mobile"],
    "delay": 400,
    "overrides": [
      { "route": "/dashboard/records/", "delay": 1000 }
    ]
  },
  "outputs": ["pdf", "html"],
  "outputDir": "./output"
}

Routes DSL

Without routes, darshana visits every discovered URL. For apps with millions of records or runs, use routes to sample:

Field	Type	Default	Description
pattern	string	required	Express-style path using :param and /**
sample	number	unlimited	Max pages to capture matching this pattern
follow	boolean	true	Whether to BFS-follow links on matching pages

First match wins.

Config reference

Top-level

Field	Type	Default	Description
title	string	hostname	Cover page and HTML header title
url	string	required	Base URL
start	string	/	Path to start crawling from
public	boolean	false	Skip auth
authStorage	string	./auth.json	Saved session path
authScript	string	—	Headless login script
outputs	string[]	["pdf","html"]	Any of "pdf", "html", "images"
outputDir	string	./darshana-output	Output directory

crawl

Field	Type	Default	Description
include	string[]	[]	Regex patterns — pathname must match all
exclude	string[]	[]	Regex patterns — pathname must not match any
maxDepth	number	5	Max BFS depth
maxPages	number	100	Hard page cap
extraRoutes	string[]	[]	Extra paths to capture (not crawled for links)
routes	Route[]	[]	Per-pattern sampling rules

capture

Field	Type	Default	Description
themes	string[]	["system"]	"system" (no injection), "dark", "light"
viewports	string[]	["desktop"]	"desktop" (1440×900) or "mobile" (390×844)
fullPage	boolean	true	Capture full scrollable height
delay	number	400	ms to wait before capture
waitFor	string	—	CSS selector (prefix $) or JS expression to await
overrides	Override[]	[]	Per-route overrides for any capture field
contextOptions	object	{}	Passed to browser.newContext()
launchOptions	object	{}	Passed to chromium.launch()
playwrightOptions	object	{}	Passed to page.screenshot()
routeOptions	object	—	{ blockPatterns: string[] } — abort matching requests

Auth

Headed handover (default): darshana opens a Chromium window, you log in, press Enter. The session is saved to authStorage and reused for 12 hours.

Headless auth script: export a default function that receives a Browser and returns the path to a saved storageState:

// auth.mjs
export default async function login(browser) {
  const context = await browser.newContext();
  const page = await context.newPage();
  await page.goto(process.env.APP_URL + '/login');
  await page.fill('#password', process.env.APP_PASSWORD);
  await page.click('button[type="submit"]');
  await page.waitForURL(/\/dashboard/);
  await context.storageState({ path: './auth.json' });
  await context.close();
  return './auth.json';
}

See examples/auth-example.mjs for a full example.

Outputs

• pdf — one page per capture, labeled header, cover page
• html — self-contained file with sidebar nav, theme/viewport filters, keyboard navigation (↑↓), viewport-correct image sizing
• images — <outputDir>/images/<viewport>/NNN-slug-theme.png

License

MIT