Minos

Hard rules for coding agents that hold at minute 1 and at minute 300.
One rule engine, two hosts: Claude Code and OpenCode.

---

Tired of Claude adding itself as co-author on every commit? Of the agent forgetting your AGENTS.md / CLAUDE.md rules an hour into the session?

Rules that live in the context window get diluted as the session grows. Rules that live in hooks don't. Minos moves your hard rules out of the model's memory and into deterministic checks that run on every command and edit, blocking or warning before the action lands.

Highlights

• Rules that survive the session: enforcement runs in hooks, outside the context window, immune to context drift and compaction
• Self-correcting: a warn/block hands the agent a message it acts on, so it fixes its own mistake before the diff reaches you, and stops forgetting the tool you told it to use
• Deterministic first: keyword and regex rules cost nothing and never drift
• AI judgment when needed: llm-judge rules ask a model a narrow yes/no question, with per-rule model choice (any claude or opencode model)
• Global + per-project config: project rules override by id, and projects can disable global rules with an audit reason
• Web config UI: rule editor, live test sandbox, judge model picker
• Agent-configurable: /minos:configure block force pushes here writes and verifies the rule for you

Note

Minos ships with no rules by default. Installing it enforces nothing until you add rules: say what you want with /minos:configure, use the web UI, or copy one of the worked rules in examples.md.

Install

Claude Code

claude plugin marketplace add FlavioZanoni/minos
claude plugin install minos@minos

(or interactively: /plugin and browse the minos marketplace)

This registers PreToolUse (Bash) and PostToolUse (Edit/Write) hooks plus the slash commands below.

OpenCode

No registry needed; Minos installs straight from GitHub as a git dependency. Two files in your project (or the global equivalents under ~/.config/opencode/):

.opencode/package.json

{ "dependencies": { "minos": "github:FlavioZanoni/minos" } }

.opencode/plugins/minos.js

export { MinosPlugin } from "minos/opencode";

The adapter maps tool.execute.before (bash commands, throws to block) and tool.execute.after (edit/write content checks). Same config files, same rules, same engine as the Claude Code plugin.

Slash commands in OpenCode (optional)

OpenCode does not load commands from plugins, only from its command directories, so the enforcement hooks above never register any. To get the same commands as the Claude Code plugin, copy the OpenCode-ready versions from this repo into your global command directory:

git clone --depth 1 https://github.com/FlavioZanoni/minos /tmp/minos
mkdir -p ~/.config/opencode/commands
cp /tmp/minos/opencode/commands/*.md ~/.config/opencode/commands/
rm -rf /tmp/minos

That registers /minos-configure, /minos-explain, /minos-global-config, and /minos-project-config (file name = command name in OpenCode). Use .opencode/commands/ inside a project instead of the global directory to scope them to one repo.

Config files

Rules live in JSONC (JSON with // comments and trailing commas):

Scope	Path	Wins on conflict
Global	~/.config/minos/rules.jsonc
Project	.minos/rules.jsonc	✔ (override by id, or disable with a reason)

See examples.md for worked examples with field-by-field explanations.

{
  "rules": [
    { "id": "no-chat-context-in-comments",
      "appliesTo": { "tools": ["Edit", "Write"], "pathGlob": ["**/*.md", "**/*.py", "**/*.ts"] },
      "trigger": { "type": "contains", "patterns": ["as discussed", "as mentioned above", "per our conversation"] },
      "action": "block",
      "message": "Comments/docs can't assume the reader has chat context. Rewrite as self-contained." },
    { "id": "no-claude-coauthor",
      "appliesTo": { "tools": ["Bash"], "commandMatch": ["git commit"] },
      "trigger": { "type": "contains", "patterns": ["Co-Authored-By: Claude", "Generated with Claude"] },
      "action": "block",
      "message": "Strip the Co-Authored-By/Generated-with trailer before committing." },
    { "id": "reinventing-the-cli",
      "appliesTo": { "tools": ["Bash"] },
      "trigger": { "type": "llm-judge", "context": "tooling", "prompt": "rules/prefer-existing-tooling.md" },
      "action": "warn" }
  ]
}

llm-judge prompt paths are resolved relative to the directory of the config file that defines the rule (so the example above expects ~/.config/minos/rules/prefer-existing-tooling.md or .minos/rules/prefer-existing-tooling.md; copy this repo's rules/prefer-existing-tooling.md there to use it). Inline promptText needs no file at all.

Editing config

Slash commands:

Claude Code	OpenCode*	What it does
/minos:configure <request>	/minos-configure <request>	Plain-language rule creation: writes the rule to the right scope and verifies it against the real engine
/minos:explain	/minos-explain	Rundown of what Minos does and which rules are active here
/minos:global-config	/minos-global-config	Web UI for ~/.config/minos/rules.jsonc
/minos:project-config	/minos-project-config	Web UI for the project's .minos/rules.jsonc

* OpenCode commands are not installed automatically; copy them in first, see Slash commands in OpenCode.

The web UI can also be launched directly, from anywhere, with no install:

npx -y github:FlavioZanoni/minos config --global
npx -y github:FlavioZanoni/minos config --project

(The -y skips npx's install prompt so it doesn't hang when an agent runs it. If you've cloned the repo, node dist/cli.js config --global works too.)

It starts a server on 127.0.0.1 (random free port), prints its URL, and opens your browser: rule list with source tags, per-rule editor, a live test sandbox to see which rules fire on a sample command or edit, and the judge model picker fed by your actual installed CLIs.

License

Apache-2.0. Copyright 2026 Flavio Zanoni. Free to use, modify, and redistribute; keep the attribution and state your changes.