jumbo-add-invariant

Agent Building

Use liberally when you discover or are told a non-negotiable constraint — something that must always be true regardless of context. Registers the invariant so future sessions never violate it.

QUICK START

How to use this skill

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Review the proposed files and risks before you approve installation.

Prompt to paste

I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/jumbocontext/jumbo.cli/blob/HEAD/assets/skills/jumbo-add-invariant/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/jumbo-add-invariant/. Do not write files or run scripts until I approve.

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Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

Add Invariant

Register an invariant with Jumbo when you discover a non-negotiable constraint — a rule that must hold true across the entire project at all times, regardless of which goal is being implemented.

Important: Invariants must be generally applicable to the project. Do not word them for a specific use case, goal, or task. An invariant that only applies during one piece of work belongs in a goal's criteria, not in the invariant registry. If you find yourself writing "when working on X" or "for the Y feature", it is not an invariant.

Before Adding

Check for an existing invariant to avoid duplication. Consider reversing, updating, or superseding a previously registered invariant before registering a new one.

Use the search subcommand to locate previously registered invariants:

jumbo invariants search -q <query>

Command Syntax

jumbo invariant add \
  --title "<Invariant title>" \
  --description "<What must always be true>" \
  --rationale "<Why this is non-negotiable>"

Bad Example

jumbo invariant add \
  --title "Session endpoint must validate tokens" \
  --description "The /api/session endpoint must check JWT expiry" \
  --rationale "Security requirement for session management"

Too narrow — applies to one endpoint. This is a requirement for a specific feature, not a project-wide invariant.

Good Example

jumbo invariant add \
  --title "All API endpoints must validate authentication tokens" \
  --description "Every endpoint that accepts authenticated requests must verify token validity, expiry, and scope before processing the request" \
  --rationale "Security compliance requirement — unauthenticated access to protected resources is a critical vulnerability"

Applies to every endpoint, not just one. States the full constraint. Rationale explains why violation is unacceptable.