Sextant

Architecture-aware engineering principles framework for Claude Code and Codex.

Sextant provides systematic, tiered workflows for the full software engineering lifecycle — bug fixes, new features, refactoring, code review, test writing, requirements refinement, debugging, shipping, sprint planning, migrations, and security audits. Like a nautical sextant that helps navigators fix their exact position before charting a course, it helps the agent understand where it is in the codebase before making changes.

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Install

Codex

Codex support is currently documented as a local development integration path, not a published one-command install flow.

The repository root is the plugin root. The Codex manifest lives at .codex-plugin/plugin.json and points to the shared skills/ directory.

For local testing, .agents/plugins/marketplace.json provides a repo-local marketplace entry that points back to this repository. Use it as a development setup reference, not as a published installation contract.

Claude

Option 1: Official Claude marketplace

/plugin install sextant@claude-plugins-official

Or use /plugin to open the interactive plugin manager, navigate to Discover, and search for "sextant".

Option 2: Via GitHub marketplace

/plugin marketplace add hellotern/sextant
/plugin install sextant@mohist-plugins

Option 3: Team configuration

Commit .claude/settings.json to your repository. All team members get sextant automatically on checkout.

{
  "extraKnownMarketplaces": {
    "sextant": {
      "source": {
        "source": "github",
        "repo": "hellotern/sextant"
      }
    }
  },
  "enabledPlugins": {
    "sextant@sextant": true
  }
}

Skills are available immediately — no restart required.

Updating

/plugin update sextant

Cursor

Option 1: Project-level install

Clone the repo and run the installer from your project directory:

git clone https://github.com/hellotern/sextant
cd your-project
python path/to/sextant/.cursor-plugin/install.py

Option 2: Global install (all Cursor projects)

python path/to/sextant/.cursor-plugin/install.py --global

Usage

• Engineering principles (§0–§6) are automatically active in every Cursor AI interaction.
• Invoke a workflow via the / command menu in Cursor chat: /sextant-fix-bug, /sextant-add-feature, /sextant-review-code, etc.
• GitNexus integration activates automatically when .gitnexus/ is present in your project.

Updating

Pull the latest version and re-run the installer:

cd sextant && git pull
python path/to/sextant/.cursor-plugin/install.py

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How It Works

For an interactive version of the loading flow diagram, see sextant_loading_flow.html.

flowchart TD
    A(["User prompt"]) --> B

    B["Host matches task type
    to a sextant-* skill"]
    B --> R1["sextant:fix-bug"]
    B --> R2["sextant:add-feature"]
    B --> R3["sextant:modify-feature"]
    B --> R4["sextant:review-code"]
    B --> R5["sextant:write-tests"]
    B --> R6["sextant:refine-requirements"]
    B --> R8["sextant:debug"]
    B --> R9["sextant:ship"]
    B --> R10["sextant:plan"]
    B --> R11["sextant:migrate"]
    B --> R12["sextant:security"]
    B --> R7["sextant (fallback)"]