OpenDesign is an open-source, local-first desktop app that lets coding agents create prototypes, dashboards, slide decks, images, video, and design systems as exportable files. It is used by people working with agent runtimes such as Claude Code, Codex, Cursor, and DeepSeek Harness. The catalogue add-ons extend the OpenDesign workflow with skills, instructions, commands, and plugins.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add nexu-io/open-design --skill build-testgit clone --depth 1 https://github.com/nexu-io/open-designWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/nexu-io/open-design/build-test)<a href="https://agentmods.dev/skills/nexu-io/open-design/build-test"><img src="https://agentmods.dev/badge/skills/nexu-io/open-design/build-test.svg" alt="Measured on agentmods" height="20"></a>- Snyk pass
- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00031 | $0.00658 |
| Opus 5 | $0.00015 | $0.00329 |
| Sonnet 5 | $0.00006 | $0.00132 |
| Haiku 4.5 | $0.00003 | $0.00066 |
Grade A, and why
build-test scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Build test
Spec §20.2 / §22.4: the "subjective critique-theater panel" is
not enough on its own — a code-migration / tune-collab run must
prove the build still passes. This atom shells out to the
project's declared test commands and emits structured signals the
devloop's until evaluator reads.
Inputs
- The active target stack (recorded in
code/index.json+plan.md's targetStack block). - The user's optional override (
od plugin run --input testCommand='pnpm test').
Default commands by framework
| framework | typecheck | test |
|---|---|---|
| next | pnpm typecheck |
pnpm test |
| vite | pnpm typecheck |
pnpm test |
| remix | pnpm typecheck |
pnpm test |
| custom | (read from package.json.scripts) |
(read from package.json.scripts) |
Output
project-cwd/
└── critique/
├── build-test.json # { build: 'passing' | 'failing', tests: 'passing' | 'failing' | 'skipped', durationMs, commandsRun: [...], failures: [...] }
└── build-test.log # raw stdout / stderr (truncated to the runner's logBudgetBytes limit, default 1 MiB)
The atom emits two signals the devloop reads:
build.passing: boolean— the typecheck command exited 0.tests.passing: boolean— the test command exited 0.
Plus the legacy critique.score so existing pipelines that read
the score keep working: 5 when both pass, 3 when only build
passes, 1 when both fail.
Convergence
Pipelines wire the atom into a devloop:
{
"id": "verify",
"atoms": ["patch-edit", "build-test"],
"repeat": true,
"until": "(build.passing && tests.passing) || iterations >= 8"
}
Anti-patterns the prompt fragment forbids
- Running tests on a partially-edited working tree (the atom
always runs after
patch-edit, and only whenplan.steps's current step is incompletedstate). - Suppressing test failures by changing test files; that violates the rewrite-plan ownership rule.
- Setting
tests: 'skipped'without a non-emptyreasonfield.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago First seen · 79 lines · 31 tokens per session scan A eb9e1d0d5cd4
build-test is a skill published in the GitHub repository nexu-io/open-design (94,527 stars, last pushed today), licensed Apache-2.0. It adds 31 tokens to every session and 658 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
ultraqa
QA cycling workflow - test, verify, fix, repeat until goal met.
debugging
Investigate failures whose root cause is still unknown — narrow the search space, instrument, and test falsifiable hypotheses. Use for intermittent or environment-dependent behavior, unexplained stack traces, regressions with no known trigger, or any symptom without a confirmed cause. Ends once the root cause is…
testing
Strategy and rules for writing or improving automated tests. Use when adding tests, improving coverage, fixing flaky tests, setting up a test suite, or deciding what and how to test. Emphasizes deterministic tests, testing behavior over implementation, and a tight validation loop. For diagnosing production failures…
bug-fix
Regression-first workflow for fixing a defect whose cause is known. Reproduce the confirmed defect, fix the root cause minimally, protect it with a regression test, and verify. If the root cause is still unknown, use the debugging skill first.
systematic-debugging
Reproduce failures, isolate root cause with evidence, and fix them through a regression test.
nw-bugfix
Bug fix workflow: root cause analysis → user review → regression test + fix via TDD.