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CircleCI Skills for Claude Code and Codex

Install and use CircleCI Skills, a plugin for Claude Code and Codex. Its Agent Skills let AI coding agents debug failing builds, optimize CI config, run the CLI, set up Smarter Testing and Chunk, and onboard projects to CircleCI.

CircleCI Skills is a plugin for AI coding agents (Claude Code and Codex). It is a bundle of Agent Skills that give the agent task-specific knowledge of CircleCI, so it can debug builds, optimize configuration, set up testing, and onboard projects without you pasting documentation into the chat.

The plugin includes six skills. Each activates automatically based on your prompt. You get expert-level results without needing to know how CircleCI works underneath.

Skill

What it does

circleci-builds

Diagnoses and fixes failing pipelines: isolates root cause from logs, distinguishes transient vs. deterministic failures, applies minimal safe patches.

circleci-config

Optimizes .circleci/config.yml for speed, cost, and reliability: caching, workspaces, parallelism, pipeline structure.

circleci-cli

Runs the day-to-day terminal loop: authenticate, validate config, watch a run after pushing, read failing logs/tests, rerun or cancel jobs.

circleci-smarter-testing

Sets up Smarter Testing (test-suites.yml): test impact analysis, dynamic splitting, auto-rerun of failed tests.

chunk

Sets up and runs CircleCI Chunk for AI-assisted CI/CD, via the web UI or chunk-cli.

onboarding

Takes a new project from zero to a passing pipeline: account/org setup, GitHub App connection, project creation, config iteration.

How to install it

Prerequisites

  • Claude Code or Codex.

  • The CircleCI CLI (used by several skills to validate configs and watch runs)

    # macOS / Linux
    curl -fLSs https://raw.githubusercontent.com/CircleCI-Public/circleci-cli/main/install.sh | bash

    # or with Homebrew
    brew install circleci
  • A CircleCI API token exported as CIRCLE_TOKEN

    export CIRCLE_TOKEN="your-personal-api-token"

Claude Code

Add the marketplace, then install the plugin:

/plugin marketplace add CircleCI-Public/skills
/plugin install circleci@circleci-public-skills

Verify it is installed:

/plugin

circleci should appear in the installed plugin list.

Codex

Clone the plugin, then add it as a marketplace in your Codex plugin manager and install circleci:

git clone https://github.com/CircleCI-Public/skills.git

You get the same set of skills as the Claude Code install.

How to use it

Describe what you want in plain language. The relevant skill activates automatically; you do not need to name it. Run the agent from inside your repository so the CLI-backed skills can infer the project and branch from the git remote.

The following are example use cases:

Debug a failing build

Diagnose and fix the build failures on my current branch.
This job keeps failing intermittently. Is it flaky, and should I just rerun it?

Optimize Configuration

Review the CircleCI configuration for this project and suggest improvements.
Our CI is slow. Tune caching and parallelism to cut runtime.

Run the CLI loop

Validate my config change before I commit.
Watch the CircleCI run for my current branch and report the results.
Show me why CI failed and which tests broke.

Set up Smarter Testing

Set up CircleCI Smarter Testing for running tests in this project.
Migrate my raw `npm test` command to a testsuite with dynamic splitting.

Use Chunk

Set up the Chunk CLI for this project.
Use Chunk to fix this failing build.

Onboard a new project

Onboard my project to CircleCI.
I have a new repo and want CI running on it. Get me started.


- License: MIT

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