j-rig — Skill Refiner

The Skill Refiner: an eval-guided improvement loop for SKILL.md files, delivered as a Claude Code plugin. Second product in the Intent Solutions agent-rig stack — J-Rig Skill Binary Eval (test) → Skill Refiner (improve) → Rollout Gate (ship).

The refiner proposes safe, minimal, bounded edits (add / delete / replace ops) to a skill and accepts an edit only if a held-out eval score strictly improves with no regression on any other case. It is a thin wrapper over the published @intentsolutions/refiner package (the j-rig refine command group in @intentsolutions/jrig-cli); it does not reimplement refiner logic.

Install

In Claude Code:

/plugin install j-rig@claude-code-plugins-plus

Then install the CLI the subcommands wrap:

npm install -g @intentsolutions/jrig-cli   # gives you the `j-rig` command

Subcommands

Each /j-rig subcommand is a thin wrapper over a j-rig refine verb. Run them against a skill directory (the folder containing the SKILL.md).

| Subcommand | Underlying CLI verb | Purpose | | --- | --- | --- | | refine bootstrap <skill-dir> | j-rig refine bootstrap | Synthesize a held-out eval set. | | refine score <skill-dir> | j-rig refine score | Score via j-rig eval (Haiku/Sonnet; never Opus). | | refine propose <skill-dir> | j-rig refine propose | Propose one bounded edit; shadow-validate it. | | refine promote <skill-dir> | j-rig refine apply | Apply an accepted proposal → new version (human-gated). | | refine status <skill-id> | j-rig refine status | Show the refiner store + event log. |

The 3-layer cost-tiered hooks (sinker · line · hook)

| Layer | Event | Fires | Mechanism | Cost | | --- | --- | --- | --- | --- | | Sinker (L1) | PostToolUse: Edit\|Write | on any SKILL.md edit | deterministic validate-skillmd Tier-2 check | $0 | | Line (L2) | Stop | at end of turn | capture rollouts → background refiner after N | $ | | Hook (L3) | PreToolUse: Bash | before git commit/push on a staged SKILL.md | agentic gate, can block via exit 2 | $$ (rate-limited) |

Why L3 is PreToolUse:Bash: only PreToolUse is in the Anthropic hooks "Can block" allowlist. PostToolUse:Bash fires after the commit already ran and cannot prevent it. The L3 Opus gate is rate-limited (default 5 min) to control cost.

See skills/j-rig/SKILL.md for the full reference.

License

Apache-2.0 © Jeremy Longshore / Intent Solutions