Run kola tests against CoreOS builds using coreos-assembler, including native and external tests
$ npx skills add coreos/coreos-assembler --skill cosa-kola -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install coreos/coreos-assembler cosa-kola --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/coreos/coreos-assembler.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/cosa-kola .claude/skills/cosa-kola && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "cosa-kola" agent skill from https://github.com/coreos/coreos-assembler/tree/main/.agents/skills/cosa-kola into .claude/skills/cosa-kola/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cosa-kola", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/coreos/coreos-assembler/tree/main/.agents/skills/cosa-kolaType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add coreos/coreos-assembler --skill cosa-kola -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install coreos/coreos-assembler cosa-kola --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/coreos/coreos-assembler.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/cosa-kola .agents/skills/cosa-kola && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "cosa-kola" agent skill from https://github.com/coreos/coreos-assembler/tree/main/.agents/skills/cosa-kola into .agents/skills/cosa-kola/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cosa-kola", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add coreos/coreos-assembler --skill cosa-kola -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install coreos/coreos-assembler cosa-kola --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/coreos/coreos-assembler.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/cosa-kola .cursor/skills/cosa-kola && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "cosa-kola" agent skill from https://github.com/coreos/coreos-assembler/tree/main/.agents/skills/cosa-kola into .cursor/skills/cosa-kola/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cosa-kola", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/coreos/coreos-assembler.git --path .agents/skills/cosa-kola--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add coreos/coreos-assembler --skill cosa-kola -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install coreos/coreos-assembler cosa-kola --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/coreos/coreos-assembler.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/cosa-kola .gemini/skills/cosa-kola && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "cosa-kola" agent skill from https://github.com/coreos/coreos-assembler/tree/main/.agents/skills/cosa-kola into .gemini/skills/cosa-kola/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cosa-kola", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install coreos/coreos-assembler cosa-kolaInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add coreos/coreos-assembler --skill cosa-kola -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/coreos/coreos-assembler.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/cosa-kola .github/skills/cosa-kola && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "cosa-kola" agent skill from https://github.com/coreos/coreos-assembler/tree/main/.agents/skills/cosa-kola into .github/skills/cosa-kola/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cosa-kola", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add coreos/coreos-assembler --skill cosa-kola -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install coreos/coreos-assembler cosa-kola --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/coreos/coreos-assembler.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/cosa-kola .opencode/skills/cosa-kola && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "cosa-kola" agent skill from https://github.com/coreos/coreos-assembler/tree/main/.agents/skills/cosa-kola into .opencode/skills/cosa-kola/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cosa-kola", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
cosa-kolaRun kola tests against CoreOS builds using coreos-assembler, including native and external tests
Cosa Kola is an agent skill from coreos/coreos-assembler. Run kola tests against CoreOS builds using coreos-assembler, including native and external tests
Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The repository describes itself as: Tooling container to assemble CoreOS-like systems. The licence is Apache-2.0.
3 steps, taken from the step headings in SKILL.md.
Read from SKILL.md and the folder at commit 4ab8b08. It shows what the files ask for, not the result of running them.
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Shell commands in SKILL.md call:
jqFrom the folder's file list and the shell code blocks in SKILL.md.
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Cosa Kola loads about 1.1k tokens when it runs. Until then it costs about 27 tokens; SKILL.md has 496 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
The full file from coreos/coreos-assembler at commit 4ab8b08, republished under its Apache-2.0 licence (© coreos). 496 words, ~1,058 tokens.
.claude/skills/cosa-kola/SKILL.md (or your agent's skills folder).This skill guides you through running kola tests against CoreOS builds using coreos-assembler.
Writing new native (Go) kola tests and cloud platform testing are not covered here. For writing external tests, refer to the docs listed below.
Do NOT duplicate these docs. Read them at runtime for command details:
| File | What it covers |
|---|---|
docs/kola.md | Kola overview, cosa kola wrapper behavior, automatic test discovery, common flags, denylists, test output logs |
docs/kola/external-tests.md | How to write and structure external tests, kola.json metadata, reboot support |
docs/kola/adding-tests.md | Adding native Go tests to kola (for reference) |
src/cmd-kola | cosa kola wrapper source -- shows how args are passed through to kola |
Before running tests you need a QEMU image in the cosa workdir and the
cosa() bash alias must be set up. Load the cosa-basics skill for both
of these -- it covers container invocation, building from source, and fetching
published builds.
All commands below assume you are in a cosa workdir (or inside the cosa
container). Read docs/kola.md for full flag documentation.
List available tests to find the one the user wants:
cosa kola listFor JSON output with descriptions:
cosa kola list --json | jq -r '.[] | [.Name, .Description] | @tsv'External tests from src/config/tests/kola/ are discovered automatically
and named ext.config.<path> (e.g., ext.config.files.aleph-version).
When you need to inspect or understand a test whose name starts with
ext.config., find its source under src/config/tests/kola/ in the cosa
workdir. The path maps directly from the test name: replace dots with /
after ext.config. and look for test.sh (and optionally kola.json or
config.bu) in that directory. For example:
| Test name | Source path |
|---|---|
ext.config.files.aleph-version | src/config/tests/kola/files/aleph-version/test.sh |
ext.config.upgrade.extended | src/config/tests/kola/upgrade/extended/test.sh |
The src/config/ directory is the cloned config repo (e.g.,
fedora-coreos-config). If it does not exist in the current directory,
check for it relative to the cosa workdir root.
Important: The cosa workdir (created by cosa init) is NOT the same as
the coreos-assembler source repository. The src/config/ directory only
exists inside a cosa workdir. Do not search the coreos-assembler source tree
for ext.config.* test files -- they won't be there. If you need to inspect
these test sources and are not currently in a cosa workdir, either navigate to
one or clone the config repo (e.g., fedora-coreos-config) directly.
Test names are glob patterns:
cosa kola run basic
cosa kola run ext.config.files.aleph-version
cosa kola run 'ext.config.*'Running cosa kola run with no pattern runs all tests (can take a long time).
Read docs/kola.md for flags like --parallel, --tag, --rerun,
--denylist-test, --ssh-on-test-failure, --append-butane, and others.
For running tests on platforms other than QEMU (e.g. AWS, GCP, Azure, ISO, metal), load the cosa-platforms skill.
Test logs are written to tmp/kola/<test-name>/. Key files: journal.txt,
console.txt, ignition.json, journal-raw.txt.gz. Read docs/kola.md
("More information on tests") for details.
ISO install tests are regular kola tests (the testiso subcommand was removed
in https://github.com/coreos/coreos-assembler/pull/4377). Run them with
cosa kola run like any other test:
cosa kola run iso.iso-offline-install.mpath.bios
cosa kola run 'iso.*'cosa kola --upgradesThis runs the run-upgrade subcommand, which tests OS upgrades. It
automatically finds parent images and caches them in tmp/kola-qemu-cache/.
© coreos, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Just SKILL.md in .agents/skills/cosa-kola of coreos/coreos-assembler.
Open the folder on GitHubat commit 4ab8b08
Cosa Kola next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Cosa Kola this skillcoreos/coreos-assembler | 395 | — | ~1.1k | Automated safety check: Pass | Apache-2.0 | |
| Bio Genome Assembly Metagenome AssemblyGPTomics/bioSkills | 1.2k | 1 repos | ~5k | Automated safety check: Pass | MIT | |
| Bio Genome Assembly Long Read AssemblyGPTomics/bioSkills | 1.2k | 1 repos | ~4.6k | Automated safety check: Pass | MIT | |
| Bio Genome Assembly Assembly PolishingGPTomics/bioSkills | 1.2k | 1 repos | ~4.7k | Automated safety check: Pass | MIT | |
| Bio Genome Assembly Hifi AssemblyGPTomics/bioSkills | 1.2k | 1 repos | ~4.6k | Automated safety check: Pass | MIT | |
| Bio Genome Assembly Assembly QcGPTomics/bioSkills | 1.2k | 1 repos | ~4.9k | Automated safety check: Pass | MIT |
GPTomics/bioSkills
Assembles microbial-community sequencing into metagenome-assembled genomes (MAGs) with metaFlye (ONT), metaSPAdes/MEGAHIT (Illumina), and hifiasm-meta/metaMDBG (PacBio HiFi), then recovers genomes…
GPTomics/bioSkills
Assembles genomes de novo from noisy long reads (Oxford Nanopore R9/R10/Dorado, PacBio CLR) with Flye (repeat graph), Canu (correct-trim-assemble OLC), NextDenovo, Shasta, Raven, wtdbg2, or miniasm…
GPTomics/bioSkills
Decides whether and how to polish a draft genome assembly to raise consensus accuracy (QV) with read-type-matched tools - Racon and medaka (ONT consensus), dorado polish, Polypolish and pypolca…
GPTomics/bioSkills
Assembles haplotype-resolved diploid and telomere-to-telomere (T2T) genomes from PacBio HiFi reads with hifiasm (HiFi-only, Hi-C, or trio phasing) and verkko (HiFi + ultralong ONT for T2T)…
GPTomics/bioSkills
Evaluates genome assembly quality across the three orthogonal axes - contiguity (QUAST auN/NG50/NGx, not bare N50), completeness (BUSCO/compleasm gene-space plus Merqury k-mer completeness), and…
GPTomics/bioSkills
Assembles a genome de novo from Illumina short reads with SPAdes (isolate/careful/sc/meta/plasmid/rna modes), MEGAHIT (low-memory, huge datasets), Unicycler (bacterial finishing/hybrid), MaSuRCA…
coreos/coreos-assembler
Initialize a COSA workdir, build or fetch Fedora CoreOS images, and launch local QEMU VMs using coreos-assembler
coreos/coreos-assembler
Develop and test changes to coreos-assembler itself -- build mantle Go binaries (kola, ore, plume), iterate on Python/shell scripts, or do full container rebuilds
coreos/coreos-assembler
Build disk images, upload to cloud providers, and run tests or spawn instances on non-QEMU platforms (AWS, GCP, Azure, ISO, metal, etc.)
Run kola tests against CoreOS builds using coreos-assembler, including native and external tests. Cosa Kola is an agent skill from coreos/coreos-assembler.
Run `npx skills add coreos/coreos-assembler --skill cosa-kola -a claude-code`. Or copy the skill folder (.agents/skills/cosa-kola in coreos/coreos-assembler) into .claude/skills/cosa-kola in your project. Claude Code loads it when a task matches its description.
Run `npx skills add coreos/coreos-assembler --skill cosa-kola -a codex`. Or copy the skill folder (.agents/skills/cosa-kola in coreos/coreos-assembler) into .agents/skills/cosa-kola in your project. Codex loads it when a task matches its description.
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add coreos/coreos-assembler --skill cosa-kola -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/cosa-kola, .gemini/skills/cosa-kola, .github/skills/cosa-kola and .opencode/skills/cosa-kola in your project.
Going by SKILL.md and its folder, Cosa Kola needs the command-line tools its instructions call (jq).
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
Cosa Kola is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
About 1.1k tokens (SKILL.md is roughly 4.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
Skills that share tags, products or a category with Cosa Kola: Bio Genome Assembly Metagenome Assembly (GPTomics/bioSkills, 1.2k stars), Bio Genome Assembly Long Read Assembly (GPTomics/bioSkills, 1.2k stars), Bio Genome Assembly Assembly Polishing (GPTomics/bioSkills, 1.2k stars) and Bio Genome Assembly Hifi Assembly (GPTomics/bioSkills, 1.2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
coreos (a GitHub organization) maintains it in coreos/coreos-assembler, which has 395 GitHub stars. The repository holds 4 skills in this directory. The repository was last updated on October 7, 2026.
Source: coreos/coreos-assembler on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.
