Reddit crypto sentiment alerts with CoinGecko in Slack

Build me an agent workflow that watches crypto chatter on Reddit, cross-references it with live market data from CoinGecko, and alerts my Slack channel when chatter and price are moving together.

Trigger: cron, every hour.

Inputs I want configurable at the top of the agent instructions: a list of subreddits to watch (default r/CryptoCurrency, r/CryptoMarkets, r/SatoshiStreetBets), the destination Slack channel, a minimum mention count per coin in the last hour (default 5), a minimum absolute 24h price change percentage (default 5), a minimum 24h trading volume floor in USD (default 5,000,000), and a per-coin cooldown window in hours (default 6) so the same coin does not alert repeatedly.

On each run the agent should:

1. For every configured subreddit, use the Reddit Retrieve Posts from Subreddit operation to pull the latest hot and new posts (last hour or so). Also call the Reddit Search Posts operation to catch any posts mentioning common ticker patterns like $BTC, $ETH, $SOL across these subreddits.

2. From the titles and bodies of those posts, extract candidate coin tickers (uppercase symbols, $-prefixed tickers) and coin names. De-duplicate and count how many distinct posts mentioned each candidate in this cycle. Drop obviously generic words and very short symbols that are likely false positives.

3. For the candidates that clear the minimum mention threshold, call the CoinGecko Coins Markets operation to fetch current price, 24h price change percentage, 24h trading volume, and market cap. Pass the candidates as names or symbols; when using symbols, set include_tokens=all so symbol matches are not limited to the top-ranked token only. Use vs_currency=usd.

4. Keep only coins that pass all of: minimum mentions, minimum absolute 24h price change, and minimum 24h volume. These are the qualifying coins.

5. For each qualifying coin, check the per-coin cooldown. The agent should persist the last alert time per coin (workflow memory or a simple state store) and skip any coin that was alerted within the cooldown window.

6. For each coin that passes the cooldown, send one concise Slack message via the Slack Bot Send a Message operation to the configured channel. Each message should include: coin name and symbol, current USD price, 24h percent change with up/down arrow, 24h volume in USD (formatted nicely, e.g. $12.3M), the count of Reddit mentions seen this cycle, and the one or two top post titles driving the chatter (with permalinks). Keep it to a single message per coin, not a thread or a digest, so each alert is glanceable.

7. After sending, update the cooldown state with the current timestamp for that coin so we do not re-alert it next hour.

If no coins qualify on a given run, stay silent. Do not send a 'nothing to report' message.

Important guardrails: respect Reddit's rate limits, only treat ticker matches as candidates if they map to a real coin in CoinGecko's response, and never present this as financial advice. The Slack message should feel like a research nudge: 'X is being talked about and moving, take a look', not 'buy this'.

Additional information

What does this prompt do?

Pulls hot and new posts from the crypto subreddits you care about and counts how often each coin is being talked about right now.
Looks up live price, 24h change, and 24h volume for each trending coin so you can see if the market is moving with the chatter.
Posts a focused Slack alert for each qualifying coin with the price, 24h move, mention count, and the top headlines driving the conversation.
Quiets itself with a cooldown window so you don't get the same coin spammed at you every hour.

What do I need to use this?

A Reddit account connected to General Input so we can read public posts on your behalf.
A free CoinGecko API key for live price and volume data.
A Slack workspace and a channel where alerts should land.

How can I customize it?

Swap in your own list of subreddits, like r/CryptoCurrency, r/CryptoMarkets, r/SatoshiStreetBets, or any niche community you follow.
Tune the alert thresholds: minimum mentions in the last hour, minimum 24h price move, and minimum 24h volume to filter out noise.
Set the cooldown window per coin (for example, no more than one alert every 6 hours) and change the destination Slack channel.

Frequently asked questions

Will this work with a free CoinGecko account?

Yes. The free Demo plan from CoinGecko is enough for hourly checks across a reasonable watchlist. If you scale up subreddits or coins aggressively, you may want a paid plan for higher rate limits.

Which subreddits should I point it at?

Start with broad ones like r/CryptoCurrency, r/CryptoMarkets, and r/SatoshiStreetBets. You can add more focused communities for specific ecosystems (Solana, Ethereum, memecoins) and the agent will treat them the same way.

How do I keep it from spamming the same coin every hour?

There is a built-in cooldown window per coin. By default a coin will not alert again for several hours after its first alert. You can raise or lower that window in the prompt.

Can I send alerts somewhere other than Slack?

This starter is wired to Slack, but you can swap the destination for email, Microsoft Teams, Discord, or any other tool we support by editing the workflow after it is generated.

Is this financial advice?

No. The agent only summarizes what people are saying on Reddit and what CoinGecko shows for the market. Treat every alert as a starting point for your own research, not a signal to trade.