vmcrawl is a Mastodon-focused version reporting crawler. It is written in Python, with a SQLite database backend. It performs perodic polling of known Mastodon instances.

Crawled Endpoints

vmcrawl may attempt to access the following endpoints of your Fediverse server:

  • /.well-known/host-meta
  • /.well-known/webfinger
  • /.well-known/nodeinfo

Based on those results, if it's determined that your server is running Mastodon, it may contact:

  • /api/v2/instance for Mastodon 4.x
  • /api/v1/instance for Mastodon 3.x
  • /api/v1/instance/peers

User Agent

The vmcrawl user agent can be identified as: vmcrawl/0.1 (https://docs.vmst.io/projects/crawler)


If you would like to stop vmcrawl from checking your instance, you can add the following to your robots.txt file:

User-agent: vmcrawl
Disallow: /

Collected Data

vmcrawl collects the following data only from instances that it identifies as Mastodon, or a related fork.

  • Domain Name
  • Software Version
  • Total Users Count
  • Active Users Count
  • Administrator Email Address
  • Source Code Repository

vmcrawl may perodically request a list of peer instances from a server, but only to discover new servers to request the data outlined above. It does not store peer information for any server.