How it works

From the card you watch to the alert you act on.

GrailPing sits on top of the same TCGplayer market data that grading forums and price-trackers cite. The difference: instead of asking you to refresh a chart all day, it watches in the background and pings you the moment your conditions are met.

You build a watchlist

Search by card name, narrow by set, and pick the printing you care about. We resolve every entry to a canonical TCGplayer product so prices stay consistent across variants and reprints.

We pull market history

On add, GrailPing fetches recent market / low / mid / high history from PokemonPriceTracker so your chart isn't empty on day one. New scrape snapshots layer on top as time goes by.

You set thresholds

Pick an absolute price target ($170), a percent move (−5% in 24h), or both. Thresholds are evaluated against the freshest snapshot, so a single dip doesn't fire repeatedly — alerts only re-arm once the market crosses back.

A scheduled scrape refreshes the data

Inngest runs the scrape on a recurring schedule. Each fetch is retry-bounded, timeout-guarded, and rate-limit-aware so we never get throttled by upstream APIs. You can also force-refresh a single card from its detail page.

Alerts fire to where you actually look

Per-user Discord webhook + transactional email. Discord pings are tagged with the card, the move, the comp, and a one-click link out. Failures are recorded — you can see what got delivered and what didn't.

Lists stay shareable, securely

Every list can publish a read-only share link with a rotating token. The raw token is shown once at creation; only a SHA-256 hash is stored. Rotate or revoke any time.

Data sources, briefly

PokemonPriceTracker — TCGplayer market/low/mid/high snapshots and 90-day history.
pokemontcg.io — canonical card metadata, set/variant data, fallback TCGplayer price block when PPT can't resolve a product.
eBay Browse API — active-listing comps (roadmap; not yet live).

Ready to set up your first watch?

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