PagePing

Watch any web page and get an email the moment it changes — hosted, free, and open source. Live: https://abundant-sardine-977.convex.site

Why

Existing page-watch tools make you choose between money and work: Visualping and Distill paywall your monitoring budget, and changedetection.io wants you to run your own server. PagePing gives you the third option — a hosted service that is both free to use and fully open source, built entirely on Convex.

Features

• 3 watch triggers — Any change on the page, keyword appears in content, or price drops below a threshold (prices parsed with $ € £ ¥ ₹ support)
• Track by email — login with just an email OTP (no passwords); every alert lands in your inbox
• Public diff pages — every watch gets a shareable /w/<id> link showing the live check history
• Realtime UI — snapshots stream into the dashboard as they happen, powered by Convex reactive queries
• Price sparkline — watch pages chart the price history of every check
• Visual snapshots — each change is captured with a full-page screenshot stored in Convex file storage

• Pause / resume any watch from the dashboard without losing its history
• Webhooks — optional webhook URL per watch; every alert POSTs a JSON payload
• AI change summaries (optional) — set OPENAI_API_KEY and each diff gets a plain-English "what changed" summary on the watch page

A cron checks watches hourly against their conditions; claimable instant rechecks let you force a check from the share page or UI.

Tech stack

Built on Convex — database, queries/mutations/actions, crons, scheduled functions, indexes, and realtime sync in one backend. Pages are fetched by Firecrawl (@firecrawl/firecrawl component) and emails are sent through AgentMail's REST API. The frontend ships as a React SPA served directly from the Convex deployment via @convex-dev/static-hosting.

Auth is custom email-OTP (code hashed with Web Crypto, session tokens, 30-day sessions).

Self-host

npm install

Create free accounts at:

1. convex.dev — hosting
2. firecrawl.dev — page fetching
3. agentmail.to — transactional email

Set your secrets on the deployment (values never committed):

npx convex env set AGENTMAIL_API_KEY <your key>
npx convex env set FIRECRAWL_API_KEY <your key>
# optional:
npx convex env set OPENAI_API_KEY <your key>   # enables AI change summaries
npx convex env set AUTH_DEBUG true   # returns debugCode from requestOtp instead of emailing

Then run the dev loop (creates your deployment and writes .env.local with VITE_CONVEX_URL / VITE_CONVEX_SITE_URL automatically):

npx convex dev      # backend + generated frontend env vars
npm run build       # tsc --noEmit && vite build
npx @convex-dev/static-hosting deploy   # deploy backend + serve dist/ from the same URL as the API

Crons (hourly checker) are defined in convex/crons.ts and install themselves with the deployment.

License

MIT — see LICENSE.