How it works
Create locally, update in place : New agent-created skills are written to ~/.hermes/skills/ (or skills.create_dir when configured - see below). Existing skills are modified where they are found, including skills under external_dirs , when the agent uses skill_manage actions such as patch (targeted or full rewrite), write_file , remove_file , or delete . External dirs are not a write-protection boundary : If an external skill directory is writable by the Hermes process, agent-managed skill updates can change files in that directory. Use filesystem permissions or a separate profile/toolset setup if shared external skills must stay read-only. Local precedence : If the same skill name exists in both the local dir and an external dir, the local version wins. Full integration : External skills appear in the system prompt index, skills_list , skill_view , and as /skill-name slash commands - no different from local skills. Non-existent paths are silently skipped : If a configured directory doesn't exist, Hermes ignores it without errors. Useful for optional shared directories that may not be present on every machine.
From the official Hermes Agent documentation.