How do I install the Model Pin Gate skill?

Run npx skillmds@latest add etanhey/model-pin-gate in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Model Pin Gate safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Model Pin Gate?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Model Pin Gate free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Model Pin Gate?

EtanHey (@etanhey) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Model Pin Gate by etanhey — Agent Skill

Name: Model Pin Gate
Author: EtanHey

File contents

Skill: Model-Pin Gate

Fleet law: canon #5 owns model policy. This skill is the Claude Code hook that enforces Fable-seat spawn pins.

Scope

Agent/Task spawns must pin a non-Fable model; Workflow agent() pins are advisory.

What It Is

model-pin-gate is a Claude Code PreToolUse hook for Task|Agent|Workflow. It reads the current session's recent assistant model from transcript_path with a bounded tail read. If the current seat is not detectable as Fable, the hook allows the tool call. If the current seat is Fable, it enforces Etan's 2026-07-02 fleet model policy:

Tool call from a Fable seat	Verdict
`Agent` or `Task` without `tool_input.model`	BLOCK: `MODELPIN_AGENT_UNPINNED`
`Agent` or `Task` pinned to a Fable model	BLOCK: `MODELPIN_FABLE_BELOW_APEX`
`Agent` or `Task` pinned to a non-Fable model (`opus`, `sonnet`, `haiku`, or another explicit non-Fable model)	PASS
`Workflow` script with `agent(` calls and fewer `model:` pins than `agent(` calls	ADVISORY: `MODELPIN_WORKFLOW_AGENT_MODEL_ADVISORY`
`Workflow` script with enough `model:` pins	PASS
unrelated tools, malformed payloads, missing/undetectable seat model	PASS fail-open

The Workflow path is intentionally heuristic and advisory-only. It counts agent( occurrences versus model: occurrences and does not attempt full JavaScript parsing inside a 500ms hook.

Hook Contract

Input is the Claude Code PreToolUse stdin payload:

{
  "hook_event_name": "PreToolUse",
  "transcript_path": "/path/to/transcript.jsonl",
  "tool_name": "Agent",
  "tool_input": { "model": "opus", "prompt": "..." }
}

Output schema:

allow: {}
block: {"decision":"block","reason":"..."}
advisory: {"systemMessage":"..."}

The hook is local-only: no network, no BrainLayer, no subprocesses, bounded stdin/transcript reads, and fail-open on malformed input or internal errors.

install-snippet.json pins the absolute Node path: $HOME/.nvm/versions/node/v22.22.0/bin/node.

Run It

bun test skills/golem-powers/model-pin-gate/evals/model-pin-gate.test.mjs
python3 skills/golem-powers/model-pin-gate/evals/run_suite.py

Programmatic: import { detectModelPin } from "./src/model-pin-gate.mjs" → detectModelPin(payload) returns { verdict, seatModel, tool, violations, advisories }.

Stated Limits

Seat-model detection depends on a recent assistant model field in the transcript. If the model is absent or unreadable, the gate allows the call.
Workflow checks are advisory-only by design. They are a cheap reminder to pin each agent() call and avoid brittle parsing in a hot hook path.

---name: model-pin-gatedescription: PreToolUse model-pin guard for Fable seats. Triggers: model pin, Fable seat, Agent spawn, Workflow spawn.---# Skill: Model-Pin Gate> Fleet law: canon #5 owns model policy. This skill is the Claude Code hook that enforces Fable-seat spawn pins.## ScopeAgent/Task spawns must pin a non-Fable model; Workflow `agent()` pins are advisory.## What It Is`model-pin-gate` is a Claude Code **PreToolUse** hook for `Task|Agent|Workflow`.It reads the current session's recent assistant model from `transcript_path` witha bounded tail read. If the current seat is not detectable as Fable, the hookallows the tool call. If the current seat is Fable, it enforces Etan's 2026-07-02fleet model policy:| Tool call from a Fable seat | Verdict ||---|---|| `Agent` or `Task` without `tool_input.model` | BLOCK: `MODELPIN_AGENT_UNPINNED` || `Agent` or `Task` pinned to a Fable model | BLOCK: `MODELPIN_FABLE_BELOW_APEX` || `Agent` or `Task` pinned to a non-Fable model (`opus`, `sonnet`, `haiku`, or another explicit non-Fable model) | PASS || `Workflow` script with `agent(` calls and fewer `model:` pins than `agent(` calls | ADVISORY: `MODELPIN_WORKFLOW_AGENT_MODEL_ADVISORY` || `Workflow` script with enough `model:` pins | PASS || unrelated tools, malformed payloads, missing/undetectable seat model | PASS fail-open |The Workflow path is intentionally heuristic and advisory-only. It counts`agent(` occurrences versus `model:` occurrences and does not attempt fullJavaScript parsing inside a 500ms hook.## Hook ContractInput is the Claude Code PreToolUse stdin payload:```json{ "hook_event_name": "PreToolUse", "transcript_path": "/path/to/transcript.jsonl", "tool_name": "Agent", "tool_input": { "model": "opus", "prompt": "..." }}```Output schema:- allow: `{}`- block: `{"decision":"block","reason":"..."}`- advisory: `{"systemMessage":"..."}`The hook is local-only: no network, no BrainLayer, no subprocesses, boundedstdin/transcript reads, and fail-open on malformed input or internal errors.`install-snippet.json` pins the absolute Node path:`$HOME/.nvm/versions/node/v22.22.0/bin/node`.## Run It```bashbun test skills/golem-powers/model-pin-gate/evals/model-pin-gate.test.mjspython3 skills/golem-powers/model-pin-gate/evals/run_suite.py```Programmatic: `import { detectModelPin } from "./src/model-pin-gate.mjs"` →`detectModelPin(payload)` returns `{ verdict, seatModel, tool, violations, advisories }`.## Stated Limits- Seat-model detection depends on a recent assistant `model` field in the transcript. If the model is absent or unreadable, the gate allows the call.- Workflow checks are advisory-only by design. They are a cheap reminder to pin each `agent()` call and avoid brittle parsing in a hot hook path.

Frequently asked questions

Model Pin Gate