# Gate Check

Find the decisions in a pipeline that do not need the expensive model and propose the...

- Repository: https://github.com/undefined-ui/second-brain-os (1169 stars)
- Category: AI and agents
- License: MIT
- Last updated: 2026-10-14
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add undefined-ui/second-brain-os --skill gate-check -g -a claude-code -y`
Codex: `npx skills add undefined-ui/second-brain-os --skill gate-check -g -a codex -y`
Cursor: `npx skills add undefined-ui/second-brain-os --skill gate-check -g -a cursor -y`
Gemini CLI: `npx skills add undefined-ui/second-brain-os --skill gate-check -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add undefined-ui/second-brain-os`

## Description

Find the decisions in a pipeline that do not need the expensive model and propose the gate for each: a rule, a classic classifier, or a small model, with fail-closed routing. Use when the user asks to cut model costs or latency, says the big model handles everything, or wants a triage / routing / filter layer in front of an agent. Analysis plus an optional baseline scaffold. Do NOT use for auditing context layout (context-audit) or for building eval suites (evals-bootstrap).

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Find the gates

Theory: [Cheap decisions](https://secondbrainos.dev/#/read/course-3-gate/cheap-decisions)
and [Gate practice](https://secondbrainos.dev/#/read/course-3-gate/gate-practice).
An agent does two kinds of work: it writes, which needs a big model, and it
decides, is this spam, which queue, does this need a person, which is a
bounded question the answer to which comes from a set you already know.
A gate is a cheap decision layer that sorts the stream so the expensive
model only sees the items that actually need judgement.

## Workflow

The rest: https://github.com/undefined-ui/second-brain-os/blob/HEAD/plugins/agents-course/skills/gate-check/SKILL.md