Measure how much Reddit is talking about any topic. Community discussion volume, growing subreddit interest, and historical activity data - all queryable from your AI without hitting Reddit API limits.
Updated 2026-08-19
Trends MCP returns a weekly Reddit subscriber series for one named community, not a dump of posts. The keyword is the subreddit name only, with no r/ prefix. Values sit on a 0-100 index with about 5 years of weekly history, which is enough to see founding ramps, sudden bans, and slow membership loss. The same MCP connection covers 25+ sources, so a community curve can sit next to Google Search and news sentiment without a second vendor contract. The free plan includes 100 requests per month. Starter is $19/month for higher volume.
Reddit publishes a public subscriber count on each community page. Trends MCP stores that count as a weekly point, then rescales the history so the peak in the requested window equals 100. An absolute volume estimate is returned next to the index when the pipeline can attach one. The useful object for an assistant is the shape: a steep climb after a news event, a plateau after moderators close the gates, or a grind higher that never makes the front page.
The series is not a post-volume counter. Post and comment firehoses move with brigades, bots, and megathreads. Subscriber count moves slower and is harder to fake in bulk. That makes it a poor tick-by-tick "what is viral this hour" feed and a better record of whether a community is still attracting people after the headline dies.
get_trends is the history call. get_growth compresses the same series into period percentages such as 3M and 6M. get_top_trends does not take a subreddit name; it reads live feeds such as Reddit Hot Posts when the task is "what is circulating now" rather than "how has this community grown."
The keyword must match the subreddit slug: wallstreetbets, personalfinance, technology. Spaces, r/, www.reddit.com/r/, and display titles such as "Wall Street Bets" fail or resolve to the wrong entity. Case is usually folded, but the safe habit is the lowercase path segment from the community URL.
One keyword is one community. There is no OR syntax for "all investing subreddits." Analysts who need a sector view query a short list of flagship communities and compare the curves. A brand name is the wrong type of keyword for this source. Brand attention belongs on Google Search, news sentiment, or a dedicated discussion dataset such as Reddit discussion data.
If the assistant needs both history and a live snapshot, split the work. History uses source='reddit' plus the subreddit slug. The live snapshot uses get_top_trends with a feed type and no keyword. Mixing a slug into the live feed call is not how that tool is specified.
The official Reddit API is built for applications that read listings, vote, and post. OAuth apps, rate windows, and user-agreement constraints sit in front of every listing pull. Returned objects are posts, comments, and user records. Reconstructing a five-year subscriber curve from those objects means polling, storing, and hoping the count field was present on every snapshot.
Trends MCP does not replace moderation tools, inbox bots, or comment search. It returns a normalized community-size series through the same MCP session that already queries search, shopping, and video. Teams that still need raw listings keep a Reddit app for that job and keep Trends MCP for the long curve.
A second gap is schema. Listing JSON is nested and changes with API versions. The trend payload is a short object: keyword, source, 0-100 value, optional volume, growth percentages, and a date/value array. Assistants reason over that shape without a Reddit SDK.
Equity and crypto desks watch specialist communities because membership often moves before a ticker becomes a mass search term. Product researchers watch hobby and troubleshooting subreddits as a proxy for category passion that never shows up in brand trackers. Recruiters and developer-relations teams watch language and tooling communities as a slow signal of hiring demand. Media desks watch city and fandom subreddits around events, then confirm with Wikipedia pageviews and Google Trends.
The shared pattern is a named community with a stable slug, not a marketing phrase. "Electric vehicles" is a search keyword. electricvehicles (if that community exists) is a Reddit keyword. Mixing the two in one source field produces empty or misleading series.
Private, banned, and quarantined communities may return gaps or a not_found style miss. Brand-new subreddits have too little history for a 5-year weekly chart to mean much; daily mode on a short window is the better first look. Subscriber counts can jump when Reddit backfills or when a community is merged. Treat a one-week cliff as a data event until a second source agrees.
The 0-100 index is relative to that community's own peak in the window. A small niche forum at 100 is not "bigger than" a default subreddit at 40. Cross-community size comparisons need the absolute volume field or an external census, not the index alone.
Quota is counted per successful data call. The free plan is 100 requests per month, not per day. Starter is $19/month. High-frequency loops that poll the same slug every hour waste quota; weekly refresh is enough for subscriber series.
Trends MCP is one MCP connection covering 25+ sources, including this Reddit subscriber series, Google Search, TikTok, and news. History is about 5 years weekly. Output is a 0-100 index plus optional volume. No Reddit OAuth app is required for the series.
The official Reddit API remains the path for listings, search, and write actions. It does not ship a clean multi-year subscriber index, and rate limits are per app rather than a simple monthly research quota.
Scrapers and third-party Reddit analytics products can show richer comment graphs. Those tools are a different job: conversation mining, not a portable trend series. Teams should check current vendor pricing for dashboards that sell comment firehoses. TikTok trends are the usual next source when the question shifts from community membership to short-video imitation.
Tools for this workflow
get_trendsChart Reddit subscriber history for a named subreddit over about 5 years and compare the curve to Google Search to see whether community membership precedes or lags mainstream awareness.
get_trends(keyword='wallstreetbets', source='reddit', data_mode='weekly')get_growthMeasure subreddit subscriber growth and benchmark it against Google Search and news volume. Sustained Reddit growth with quiet news coverage often means the topic is still concentrated in one community.
get_growth(keyword='wallstreetbets', source='reddit, google search, news volume', percent_growth=['3M', '6M'])get_ranked_trendsRank keywords by Reddit discussion growth to surface topics that are gaining momentum in enthusiast and early-adopter communities before they hit mainstream media.
get_ranked_trends(source='reddit', sort='yoy_pct_change', limit=30)get_top_trendsSee which Reddit threads are circulating now, with no keyword. Reddit Hot Posts and World News feeds list stories driving conversation that day.
get_top_trends(type='Reddit Hot Posts', limit=25)FAQ