Hermes Agent has the context engine plugin installed but does not take effect, usually without switching context.engine to the corresponding plugin. In the official plugin system, context engine belongs to the provider plugin, which is a single option and will not automatically replace the default compressor just because you have installed the plugin.
Check the current engine first
Check out the context.engine in ~/.hermes/config.yaml. The default is usually compressor. If you want to use a plugin engine, you must explicitly set it to the plugin name, or select it through the Provider Plugins area of hermes plugins.
Why not auto-enabled
The context engine affects how long sessions retain, compress, or retrieve information and is a core behavior. Hermes employs radio and explicit enablement to avoid multiple plugins taking over the context at the same time, leading to unpredictable results.
Checklist
- Whether the plugin is installed and enabled.
- Whether the plugin name matches what is written in
context.engine. - Whether the session was restarted.
- Whether the plugin failed to load or the dependencies were missing in the logs.
If you just want to reduce the token, you don't necessarily need to change the context engine. It is usually more straightforward to configure the file reading range, tool loop, and compression model first.
