Hermes Agent v0.23.1 fixes a bug that quietly broke plugin installs

The bug: a catalog that got too big

Hermes Agent is an open-source agent tool with a command-line interface, desktop and web apps, and a plugin system. As github.com reported in the release notes for v0.23.1, a plugin catalog problem began after the catalog's website was redeployed on November 9. A plugin catalog is a single file that lists the add-ons you can install, along with their current versions.

After that deploy, the published catalog file grew larger than the 2 MiB limit that Hermes clients accept. (A MiB is a unit of file size, a little over a megabyte.) When a client rejects the file, it does not raise an error. It quietly uses the older copy of the catalog that came bundled with the software.

What users would have seen

The effects were subtle. Running hermes plugins install <name> could fail to find plugins added since your last update. For plugins it did find, it installed the version frozen into your release, not the latest one.

It also missed entries that had been removed from the live catalog. So a plugin that maintainers had pulled could still look installable from the old built-in list.

The fix raises the limit to 16 MiB, which lets clients read the live catalog again. The notes credit a community member, @100yenadmin, and tie the change to issue #151856 and pull request #151860. The catch is that nothing changes for older software. Installs on v0.23.0 or earlier keep using the stale fallback until they update.

A small tag with a large pile behind it

Patch releases are usually tiny, but this one is not. The project says it gathers roughly 618 pull requests (proposed code changes that were accepted) merged since v0.23.0. Measured at one specific commit, the window covers 2,578 commits that are not merges, across 2,781 changed files. That is about 151,690 lines added and 62,595 removed, plus 409 closed issues.

The maintainers say they are not writing it all up here. Curated release notes covering everything from v0.23.0 onward, with highlights and full contributor credits, will come with v0.24.0. They state that nothing in the window is being skipped.

Features mentioned but not yet explained

The notes do name a number of changes without describing them in detail. Treat this as a preview, not documentation:

• In the terminal interfaces, pressing Esc now steps back through a conversation, replacing the earlier rewind list.
• Group chats can run through a gateway without the Desktop app, and can include bots running on other computers.
• Desktop and the web app now share saved gateway connections.
• The built-in browser can use your real browser profile for sign-in, and can fill saved logins from its address bar.
• New commands include hermes gateway attach for local clients and hermes clipboard image --json.
• The plugin interface gains session-scoped environment values, JSON-RPC methods and events, one-shot auxiliary language-model tasks, a conversation ID that stays stable through compression, and two new hooks.
• Transcript and handoff reads are faster, and many new catalog entries were added.

The notes do not say how any of these work, so details will have to wait for v0.24.0.

How to get the update

The route depends on how you installed it. The Microsoft Store app updates through the Store. On the command line, run hermes update or run the installer one-liner again. Docker and Hermes Cloud users should pull nousresearch/hermes-agent:stable (or :latest).

If you installed the desktop app from a downloaded .exe or .dmg file, this patch does nothing for you. That app will pick up the changes with a later bundled release.

Because a very large batch of changes sits behind this tag, treat the update with care if agents run unattended. Test it first, and keep a copy of your working setup so you can go back.