after-install.md

Configure the session-and-model header

1. Add an exact custom:<name> rule under plugins.entries.hermes-custom-header-plugin.providers in ~/.hermes/config.yaml.
2. Set its header field to the request header understood by the downstream gateway, for example X-Olla-Session-ID.
3. Ensure every named custom provider has a unique base_url.
4. Restart the Hermes gateway or start a new CLI session.

The plugin sends <session_id>:<model> as the header value. It does not require an additional secret and does not configure the provider's models.

Copy the complete configuration and verification recipe from the repository README.