Built-in skills load from a skills/ directory shipped with the prime-agent package, registered as a new lowest-precedence 'builtin' source so user, project, and package skills with the same name win. Disable via the enableBuiltinSkills setting, /settings toggle, --no-skills, or per-skill override patterns. Ships one comprehensive prime-intellect skill: ecosystem overview and prime CLI workflows, with on-demand references for environments/evals/ training, sandboxes/tunnels, inference, and compute/storage, plus the live-docs pattern (docs.primeintellect.ai/<page>.md, llms.txt). Co-authored-by: Claude Fable 5 <noreply@anthropic.com>