Mastodon Hashtag Search & Fediverse Monitor API

Search a hashtag across multiple Mastodon instances and get back structured posts with engagement counts — no login, no API token, no anti-bot workarounds. Fediverse content is spread across thousands of independent servers instead of one central platform, so this pools results from a configurable list of instances in one call.

Tutorial: how to run it

1. Click Try for free (or Start) on this page.
2. Fill in hashtag — or leave the prefilled technology example to see it work immediately.
3. Adjust instances to add or remove which Mastodon servers get queried.
4. Click Start and open the Output tab once the run finishes.
5. Each row is one post, with text, author, and engagement counts (favouritesCount, reblogsCount).

Common questions, answered directly

How do I search Mastodon for brand or keyword mentions?

Pass a hashtag and a list of instance domains — it queries each instance's public timeline API directly and returns structured, deduplicated posts, no login required.

Is there an API to monitor hashtags across the Fediverse?

Yes — since Fediverse content is spread across thousands of independent servers instead of one central app, this pools results from a configurable list of instances in a single call instead of you querying each one by hand.

How do I track my brand across multiple Mastodon instances at once?

Add your target instances to the instances list and this fetches and merges results from all of them in one run.

What you can use this for

• Brand & topic monitoring across the Fediverse, where mentions of your product or industry are scattered across many servers instead of one app.
• Research into a niche or growing platform community not well covered by mainstream social listening tools.
• Competitive/market intelligence in spaces (open source, indie tech, journalism) that lean heavily toward Mastodon over corporate platforms.

Input

Field	Description	Default
hashtag	Hashtag to search, without #	technology
instances	List of instance domains to query	mastodon.social, mastodon.online, fosstodon.org
onlyMedia	Restrict to posts with an image/video/audio attachment	false
maxResultsPerInstance	Max posts to fetch per instance	100

Every field has a working default — hit Start with no changes and you'll get results.

Output

One row per post:

{
  "id": "112233445566778899",
  "instance": "mastodon.social",
  "url": "https://mastodon.social/@user/112233445566778899",
  "text": "post text with HTML stripped",
  "createdAt": "2026-09-01T12:00:00.000Z",
  "author": { "username": "user", "acct": "user@mastodon.social", "displayName": "..." },
  "favouritesCount": 4,
  "reblogsCount": 1,
  "repliesCount": 0,
  "tags": ["technology"]
}

Pricing

Pay-per-event: $0.005 per post fetched. No subscription, no minimum.

Actor recommendations

• 🌍 Remote Job Listings Aggregator API — same no-login, structured-monitoring approach, applied to 7 remote job boards.
• 📈 AI Visibility Checker — for checking brand mentions in AI assistant answers, not just social posts.
• 🔎 Grounded Research API — for turning any monitoring data into a cited, structured research answer.