GopherWatch is a webapp for subscribing to notifications about new versions of go modules seen in a go module transparency log (sum database), e.g. https://sum.golang.org.

The Go toolchain uses proxy.golang.org to fetch modules (with "go get" or "go install). The proxy adds all modules to sum.golang.org. This means published library modules with a release tag (e.g. v1.2.3) are almost certain to turn up in the transparency log. Go modules that are applications are likely to turn up as well: as soon as someone runs "go install $module@$version", with "latest" as version, or a specific tag.

https://www.gopherwatch.org/ is a public instance running GopherWatch.

GopherWatch allows registering a new account and add/remove subscriptions to modules. For example, you can register modules of commands that you use, or your dependencies, or anything published in your organization. You can ask for an exact match, or whole-domain/path prefix matches. You can filter updates by version: whether to notify for pre-release versions.

GopherWatch periodically forwards its local state of the transparency log, matches all new/updated go module (versions) against the subscriptions, and sends out emails about changes. Since there is no real-time feed for appends to the transparency log, and we don't want to overload the service, there will be some delay in receiving notifications (typically up to 30 minutes).

GopherWatch also has a DNS server (with DNSSEC support) for querying the latest version(s) of a module, or of the Go toolchain. For example:

$ host -t txt mox.mjl_2d._.github.com.v0.l.gopherwatch.org.
mox.mjl_2d._.github.com.v0.l.gopherwatch.org descriptive text "v=v0.0.11 t=66fa7e15"

$ host -t txt toolchain.v0.l.gopherwatch.org.
toolchain.v0.l.gopherwatch.org descriptive text "v=go1.23.1 k=cur t=66fa7e15; v=go1.22.7 k=prev t=66fa7e15"

To compile:

CGO_ENABLED=0 go install github.com/mjl-/gopherwatch@latest

You'll need a config file to run it:

./gopherwatch genconf >gopherwatch.conf

Possibly edit the config file. Run it:

./gopherwatch serve

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Created by Mechiel Lukkien, mechiel@ueber.net.

Code is under MIT (LICENSE.MIT), except cache.go and client.go, which are from golang.org/x/mod (BSD-3-clause). Also see licenses of dependencies.