Create Price Drop Alert

WHAT IT DOES

This tool monitors token prices using the CoinGecko API and alerts you when a price drops. You can set alerts for an absolute price drop (below a specific USD value) or a percentage drop from a baseline price. The tool polls CoinGecko at your specified interval and triggers an alert when the condition is met. All alert configurations are stored in-memory — no data is persisted across page reloads.

HOW TO USE

Connect your MetaMask wallet using the Connect button. Give your alert a name, enter the token symbol (use CoinGecko IDs like "ethereum", "bitcoin", "polygon"), choose the condition (absolute price below threshold or percent drop from baseline), set the threshold value, and choose a check interval (5-300 seconds). Click "Create Alert" to start monitoring. Active alerts appear in the list. When a price drop is detected, the alert status changes to "Triggered" and the event appears in the Price Drops log with a red indicator. Use "Remove" to delete an individual alert or "Clear All" to remove all alerts and history.

TECHNICAL MECHANISM

The tool does not read from the blockchain — it uses the CoinGecko public API's /simple/price endpoint. For each active alert, it creates a JavaScript interval that runs at the user-specified frequency. On each interval tick, the tool constructs a request to CoinGecko using the token symbol and fetches the current USD price. For absolute price alerts, the fetched price is compared against the configured threshold. For percentage drop alerts, the tool stores the first observed price as a baseline, then calculates the percentage drop on each check. If the price drops by more than the configured percentage, the alert triggers. The tool includes a price history log that displays recent checks and drops. All alert configurations and state are stored in-memory variables — no data is persisted to disk.

WHAT IT CANNOT SEE

This tool cannot persist alerts across page reloads because it runs in an opaque-origin sandboxed frame with no storage access. It cannot send push notifications or emails without external services. It cannot provide real-time price data if the CoinGecko API is unavailable or rate-limited. It cannot detect price drops on tokens not listed on CoinGecko. It cannot detect drops below the configured polling interval — a drop that occurs between checks will not be detected. It cannot detect intra-day volatility without more frequent polling, which may hit rate limits. It cannot detect price drops on non-EVM networks. It cannot provide trading signals or investment advice. It cannot detect percentage drops that occur between checks. It cannot detect price drops that happen during API downtime.

PLEASE NOTE

This tool works only with EVM-compatible wallets connected via the BGWallet bridge, but the price data comes from CoinGecko and is not network-specific. The token symbol must match CoinGecko's ID exactly — common IDs include "ethereum", "bitcoin", "matic-network", "binancecoin", "solana", "avalanche-2", "arbitrum", "optimism". CoinGecko's public API has rate limits — frequent requests may be throttled. For percentage drop alerts, the baseline is set on the first successful price fetch and is not updated unless you recreate the alert. Alerts are in-memory only and will be lost when the page is refreshed or closed. This tool is provided as a lightweight price monitoring utility and should not be used as a financial trading signal or investment decision tool.