agents · review · first seen Nov 10, 10:32 UTC

NousResearch ships Hermes Agent v0.23.1 plugin catalog fix

Hermes Agent v0.23.1 shipped a larger plugin catalog size cap on November 9, 2026. If you install plugins, updating matters because the live catalog can be used again instead of the bundled copy.

L0 · primary1 source4 claims checked4 min read

What shipped

This is a shipped patch release, not a scheduled fix. The plugin catalog published after its site deploy exceeded the 2 MiB limit accepted by clients. Installs then silently fell back to the catalog bundled with the installed release. In v0.23.1, the accepted size cap rises to 16 MiB, allowing those installs to use the live catalog again. The change addresses which catalog an install consults; it does not by itself describe a new plugin or a new install command. [1][2]

The fallback had three practical effects described in the release excerpt. The `hermes plugins install` command could not find plugins added after a user's last update. It could install the version pin bundled with that release rather than the current one. It could also miss newer removed entries. Those are catalog-selection problems, not evidence that every existing plugin installation failed. The patch targets that selection by accepting the larger published catalog. [1][2]

The version boundary matters. Installs that remain on v0.23.0 or older keep falling back to their bundled catalog until they update. The release also says that the desktop app installed from an .exe or .dmg installer does not change in v0.23.1. Do not treat this patch as a desktop-app change merely because the release covers other distribution channels. [1][2][3]

Why it matters if you build

If your workflow discovers a plugin by name and installs it with `hermes plugins install`, an older client can make a recently added plugin appear unavailable even though the published catalog contains it. Updating to v0.23.1 changes the catalog that install can use. That is a reason to act today if plugin discovery is blocking work; repeatedly trying the same install on v0.23.0 or older does not address the stated fallback condition. [1][2]

The version pin and removed-entry effects deserve a separate check. A successful install on an older release was not necessarily an install against the current catalog: it could use the pin shipped with that release and miss a newer removal. For a builder who relies on a particular plugin, the useful comparison is the result before and after updating, not merely whether both commands complete. The excerpt does not provide a plugin name or a specific expected pin to use as a universal test. [1][2]

The new limit is 16 MiB, not an assurance that any future catalog size will work. The sources establish the size-cap change and the return to the live catalog for this patch. They do not establish a broader guarantee about later catalog growth, nor do they identify a separate change for .exe- or .dmg-installed desktop apps. Keep the decision narrow: update the plugin-installing client when live catalog entries matter to your work. [1][2]

How to try it today

1. Check whether the Hermes Agent version you use for plugin installs is v0.23.0 or older.
2. If it is, update that installation to v0.23.1 before testing catalog-dependent installs.
3. Run `hermes plugins install` for a plugin you expected to find in the live catalog but could not find before the update.
4. If a version pin matters to your workflow, compare the install result with the pin you previously received; do not assume the old result came from the live catalog.
5. If you use the desktop app installed from an .exe or .dmg, do not expect a desktop-app change from this release.

What we checked

Every claim below was walked down the source ladder. The rung is how close the source is to the thing itself; the tense is the source's own.

1. shipped L0 · primary

   Hermes Agent v0.23.1 was released on November 9, 2026.

   per GitHub releases · NousResearch/hermes-agent (L0)
2. shipped L0 · primary

   Hermes Agent v0.23.1 raises the plugin catalog size cap from 2 MiB to 16 MiB.

   per GitHub releases · NousResearch/hermes-agent (L0)
3. shipped L0 · primary

   Plugin installs on v0.23.0 or older continue to fall back to the bundled catalog until users update.

   per GitHub releases · NousResearch/hermes-agent (L0)
4. shipped L0 · primary

   The desktop app installed from an .exe or .dmg installer does not change in this release.

   per GitHub releases · NousResearch/hermes-agent (L0)

What is not confirmed

The supplied sources do not name a particular plugin that will become available after updating, provide a test result for an individual installation, or specify what happens if the published catalog later exceeds 16 MiB. They also do not establish that this patch changes the .exe- or .dmg-installed desktop app. Those limits matter when diagnosing a specific failed install: the release explains the fallback and its fix, but it cannot confirm the outcome for your plugin without trying it. [1][2][3]

Who should act, who should wait

Move now if you use `hermes plugins install` and need recently added entries, current catalog pins, or newer removed entries to be reflected in installs. Update to v0.23.1, then retry the relevant install. Wait if none of those catalog effects bears on your work, or if your decision is about a change to the .exe- or .dmg-installed desktop app; this release does not establish one. Staying on v0.23.0 or older means accepting the bundled-catalog fallback for plugin installs until you update. [1][2][3][4]

Sources

• Hermes Agent v0.23.1 — GitHub releases · NousResearch/hermes-agent L0 · primary