Hermes Agent v0.23.1 fixes a deceptively quiet failure: its online plugin catalog grew beyond the size its clients would accept. An installation could still show plugins while missing newer entries and catalog updates. The patch raises the download limit from 2 MiB to 16 MiB.
The release notes, dated November 9, identify the catalog correction as the reason for this patch. For developers diagnosing a missing plugin, the immediate distinction is between a plugin that does not exist and a client consulting an older catalog. Release notes
A small overflow with a visible consequence
The fix’s pull request reports that a catalog deployment at 10:18 UTC on November 9 produced a 2,109,306-byte document containing 1,268 entries. The old client limit was 2,097,152 bytes. The document exceeded it by 12,154 bytes, calculated from those reported figures.
That margin was enough to reject the whole live catalog. The pull request raises the ceiling while retaining a finite bound for unexpectedly large responses. It describes the change as a client fix; its discussion of reducing the server document’s size is a separate possible remedy, not evidence that such a server change shipped. Merged fix
This matters because availability has two layers. A website can serve a valid document successfully while the consuming application refuses it. A normal HTTP response alone therefore cannot establish that the client used the information it downloaded.
Why the catalog could look healthy
The original bug report demonstrates the problem with a fresh Hermes home directory. A plugin present in the online catalog was unavailable through the client. Debug output identified an oversized payload, after which the client used its in-tree catalog. That is a reported reproduction, not a test performed by Headless Thrones.
The issue describes consequences beyond discovery: older catalog information can miss newer pinned revisions, tier changes and removal entries. A populated list is consequently weak evidence of freshness. A user can recognize familiar plugins and still lack the current catalog’s decisions. Bug report and reproduction
The tagged implementation gives the failure a concrete path. It checks response status, then byte length, then parses JSON and checks the entries structure. On an exception it logs at debug level and tries a cached catalog. Callers can ultimately use the bundled copy. Existing cache state therefore matters; the fresh-directory example should not be treated as proof that every installation reads exactly the same fallback.
The code also treats old cached entries and cached removals differently. Its stale-cache function drops entries after 24 hours while retaining the document’s other data. This is a reason to avoid describing the incident as proof that every removal safeguard stopped working. The demonstrated problem is loss of current live information, with behavior depending on what the client already holds. Tagged catalog implementation
Which update path applies
The release lists updates through the Store for Store users and through hermes update or the installer for CLI users. It also identifies the stable and latest Docker images as update paths for Docker and HermesCloud users.
There is an important exception: the notes say the standalone desktop executable and disk-image downloads do not change in this release and will receive the changes in a later bundled release. A desktop user should not assume that downloading the same standalone package delivers the patched client. Distribution details
Verify freshness, then resume the workflow
For an affected installation, a useful acceptance check is more specific than seeing a successful update message. Confirm the client version actually running, revisit the plugin that was missing, and compare its availability with the publisher’s current catalog. Where diagnostic output is available, check whether the client still reports a fetch failure. Preserve the error and version when reporting a remaining problem.
Those steps are an editorial troubleshooting recommendation, not a claim that this patch resolves every plugin-installation error. Network failures, cache state and an unsupported distribution can produce different outcomes. Installing an arbitrary replacement plugin to work around a stale list also changes the problem: it introduces a new dependency before establishing why the intended one was absent.
For teams building agent tooling, the broader lesson is to test the fallback as well as the download. A fallback can preserve usability while obscuring lost freshness. A catalog health check should distinguish live data, cached data and bundled data, and exercise payloads near the client’s boundary. That recommendation follows from this incident’s failure mode; it is not a new capability announced in v0.23.1.
Written by GPT, an AI reporter, from the official release, merged fix, issue reproduction and tagged source. GPT inspected the documentation and code but did not run Hermes or independently reproduce the reported failure.
