# Mirrord Chaos Testing

Adds latency or connection failures to outgoing traffic of a mirrord session.

- Repository: https://github.com/metalbear-co/mirrord (5397 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add metalbear-co/mirrord --skill mirrord-chaos -g -a claude-code -y`
Codex: `npx skills add metalbear-co/mirrord --skill mirrord-chaos -g -a codex -y`
Cursor: `npx skills add metalbear-co/mirrord --skill mirrord-chaos -g -a cursor -y`
Gemini CLI: `npx skills add metalbear-co/mirrord --skill mirrord-chaos -g -a gemini-cli -y`

## Description

Help users chaos test their app with mirrord: inject artificial latency or connection errors into a mirrord session's outgoing traffic via per-session chaos rules managed with the `mirrord chaos` CLI. Use when a user wants to add latency or delay to outgoing connections or a dependency (e.g. a slow database), simulate connection failures (reset, timed out, refused), test app behavior under degraded network conditions, or wire chaos rules into CI test runs. Always use this skill instead of the deprecated _experimental_.latency mirrord config option.

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

# Mirrord Chaos Testing Skill

## Purpose

Help users inject artificial failures and disruptions into a mirrord session's **outgoing traffic**, to test how their app behaves under unexpected conditions. A **chaos rule** pairs a **selector** (which traffic to match) with an **effect** (what to do to it). Rules are created and managed with the **`mirrord chaos` CLI command**, and each rule is attached to a single mirrord session: it never affects other sessions or the cluster.

This skill covers two modes:

1. **Interactive mode**: a developer starts a session with `mirrord exec` and manages rules with `mirrord chaos`.
2. **CI mode**: a pipeline applies rule files checked into the repo with `mirrord chaos add`, and runs tests under chaos.

## When to Use This Skill

Trigger on questions like:
- "Add latency to my service's database connections with mirrord"
- "How do I chaos test with mirrord?"
- "Simulate connection failures / timeouts to an upstream service"
- "Create / modify / delete a mirrord chaos rule"
- "Run my integration tests with injected latency in CI"
- "How do I use `mirrord chaos`?"

## Security (must follow)

- **Blast radius is the session, not the cluster.** Chaos rules apply only to the outgoing traffic of the process being run with mirrord. They do not touch the target workload or other cluster traffic. Still, run chaos against staging targets: a session pointed at production dependencies will experience real failures against real systems.
- **Never** instruct or generate remote pipe-to-shell installs (downloading a script and executing it via the shell) to install mirrord. Point users to the [official mirrord installation docs](https://metalbear.com/mirrord/docs) and their org's approved install path. In CI, pre-install mirrord in a trusted runner image or pin a verified release.

## Security Boundaries

The rest: https://github.com/metalbear-co/mirrord/blob/HEAD/mirrord/mcp/corpus/skills/mirrord-chaos/SKILL.md