Agent = Model + Harness + Skills
The vocabulary behind every guardrail on this site
An agent is three separable things, not one black box. The model is a function from context to next action: it reasons and proposes, and the same input can yield different output from one run to the next. The harness is deterministic code that owns everything the model cannot: state, tool dispatch, permissions, the sandbox, context budget. Skills are loaded into context and the tool set on demand, changing what the agent knows and can call without touching the model or the harness. Claude is the model, Claude Code is the harness, and our accelerators are the skills.
Soft Constraints and Hard Constraints
Profiles, skills and conventions are followed with high probability, not certainty. Cheap to change, and good for style, structure and idioms.
Validators, schema checks, guards and gates are followed always, or the action is refused. Costlier to build, but testable.
Every accelerator previews before acting and refuses the wrong target, reports missing dependancies and directs the user on how to resolve issues.