Reproduce Chat States
different-ai/openwork
Fires known chat states in the running OpenWork desktop app, such as provider errors, retries and tool steps, so you can check how each renders.
Build a minimal, controlled WebContainer smoke test that boots once, mounts a small project, observes process exit, and captures the preview URL.
Install Stackblitz Hello World
$ npx skills add jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install jeremylongshore/tons-of-skills-marketplace stackblitz-hello-world --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/jeremylongshore/tons-of-skills-marketplace.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/.curated/stackblitz-hello-world .claude/skills/stackblitz-hello-world && 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 "stackblitz-hello-world" agent skill from https://github.com/jeremylongshore/tons-of-skills-marketplace/tree/main/skills/.curated/stackblitz-hello-world into .claude/skills/stackblitz-hello-world/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "stackblitz-hello-world", 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/jeremylongshore/tons-of-skills-marketplace/tree/main/skills/.curated/stackblitz-hello-worldType 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 jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install jeremylongshore/tons-of-skills-marketplace stackblitz-hello-world --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/.curated/stackblitz-hello-world .agents/skills/stackblitz-hello-world && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "stackblitz-hello-world" agent skill from https://github.com/jeremylongshore/tons-of-skills-marketplace/tree/main/skills/.curated/stackblitz-hello-world into .agents/skills/stackblitz-hello-world/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "stackblitz-hello-world", 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 jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install jeremylongshore/tons-of-skills-marketplace stackblitz-hello-world --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/.curated/stackblitz-hello-world .cursor/skills/stackblitz-hello-world && 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 "stackblitz-hello-world" agent skill from https://github.com/jeremylongshore/tons-of-skills-marketplace/tree/main/skills/.curated/stackblitz-hello-world into .cursor/skills/stackblitz-hello-world/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "stackblitz-hello-world", 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/jeremylongshore/tons-of-skills-marketplace.git --path skills/.curated/stackblitz-hello-world--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 jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install jeremylongshore/tons-of-skills-marketplace stackblitz-hello-world --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/.curated/stackblitz-hello-world .gemini/skills/stackblitz-hello-world && 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 "stackblitz-hello-world" agent skill from https://github.com/jeremylongshore/tons-of-skills-marketplace/tree/main/skills/.curated/stackblitz-hello-world into .gemini/skills/stackblitz-hello-world/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "stackblitz-hello-world", 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 jeremylongshore/tons-of-skills-marketplace stackblitz-hello-worldInstalls 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 jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/.curated/stackblitz-hello-world .github/skills/stackblitz-hello-world && 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 "stackblitz-hello-world" agent skill from https://github.com/jeremylongshore/tons-of-skills-marketplace/tree/main/skills/.curated/stackblitz-hello-world into .github/skills/stackblitz-hello-world/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "stackblitz-hello-world", 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 jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install jeremylongshore/tons-of-skills-marketplace stackblitz-hello-world --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/.curated/stackblitz-hello-world .opencode/skills/stackblitz-hello-world && 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 "stackblitz-hello-world" agent skill from https://github.com/jeremylongshore/tons-of-skills-marketplace/tree/main/skills/.curated/stackblitz-hello-world into .opencode/skills/stackblitz-hello-world/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "stackblitz-hello-world", 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.
Facts
- Skill name
stackblitz-hello-world- GitHub stars
- 2.8k
- Token cost
- ~1.1k tokens
- SKILL.md length
- 489 words
- Files
- 2 (incl. references)
- Skills in repo
- 3,342
- Repo updated
- First seen
- Licence
- MIT
At a glance
Build a minimal, controlled WebContainer smoke test that boots once, mounts a small project, observes process exit, and captures the preview URL.
- Works in 6 steps: Confirm the current package and browser… → Reuse or create a singleton owner for… → Define a tiny synthetic project with a… → …
- Proving browser/runtime compatibility before building a larger in-browser development experience
- SKILL.md covers Overview, Prerequisites, Tool Discipline and Current Contract, plus 7 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Stackblitz Hello World is an agent skill from jeremylongshore/tons-of-skills-marketplace. Build a minimal, controlled WebContainer smoke test that boots once, mounts a small project, observes process exit, and captures the preview URL. Use when proving browser/runtime compatibility before building a larger in-browser development experience. Trigger with "StackBlitz hello world", "test WebContainers", or "run Node in the browser".
Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/official-docs.md`). Compatibility notes: Designed for Claude Code
It sits in Testing & QA, covering QA and bug reports. The repository describes itself as: Model-agnostic agent-skills platform with a harness-free canonical layer, verified adapters, and the ccpi package manager. Explore at tonsofskills.com. The licence is MIT.
When your agent uses it
- Proving browser/runtime compatibility before building a larger in-browser development experience
- With StackBlitz hello world
- Test WebContainers
- Run Node in the browser
Example prompts
- “StackBlitz hello world”
- “test WebContainers”
- “run Node in the browser”
- “/stackblitz-hello-world”
Requirements
- Compatibility (from SKILL.md): Designed for Claude Code
- Pre-approved tools (allowed-tools): Read, Glob, Grep, WebFetch, Write, Edit
Workflow steps
6 steps, taken from the first numbered list in SKILL.md.
- Confirm the current package and browser support assumptions from repository evidence.
- Reuse or create a singleton owner for the WebContainer instance.
- Define a tiny synthetic project with a locked dependency set and explicit start script.
- Mount the tree, spawn the repository-approved install command, stream bounded status output, and fail on a nonzero exit.
- Subscribe to readiness and error events, start the server, and attach the emitted URL to the intended preview element.
- Record cleanup behavior for listeners, processes, and teardown() when the owning view is permanently disposed.
What it can do on your machine
Read from SKILL.md and the folder at commit cfae287. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
ReadGlobGrepWebFetchWriteEdit
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
webcontainers.io
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Compatibility
Designed for Claude Code
From compatibility in the SKILL.md frontmatter.
Context cost
Stackblitz Hello World loads about 1.1k tokens when it runs, and up to ~1.4k if it reads all its reference files. Until then it costs about 92 tokens; SKILL.md has 489 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.
Safety
Auto-check: notes
The automated check noted patterns worth knowing about, such as sudo or a known installer.
- NoteMentions a .env fileSKILL.md:45
API keys, registry tokens, cookies, or `.env` data. If commercial API-key configuration or organization auth is require
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.
SKILL.md
The full file from jeremylongshore/tons-of-skills-marketplace at commit cfae287, republished under its MIT licence (© jeremylongshore). 489 words, ~1,112 tokens.
Download SKILL.mdSave it as
.claude/skills/stackblitz-hello-world/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- stackblitz-hello-world
- description
- Build a minimal, controlled WebContainer smoke test that boots once, mounts a small project, observes process exit, and captures the preview URL. Use when proving browser/runtime compatibility before building a larger in-browser development experience. Trigger with "StackBlitz hello world", "test WebContainers", or "run Node in the browser".
- allowed-tools
- Read, Glob, Grep, WebFetch, Write, Edit
- compatibility
- Designed for Claude Code
- argument-hint
- [project-path] [entrypoint]
- version
- 1.7.0
- author
- Jeremy Longshore <jeremy@intentsolutions.io>
- license
- MIT
- tags
- saas, stackblitz, webcontainers, quickstart
- model
- inherit
- effort
- medium
WebContainer Controlled Smoke Test
Overview
This skill adds or plans the smallest useful WebContainer proof: one instance, one deterministic file tree, one bounded dependency install, one server process, and one preview readiness observation. It avoids presenting a tutorial snippet as a production architecture.
Prerequisites
- A browser application already passing the StackBlitz integration preflight
- Cross-origin isolation and HTTPS behavior verified for the target environment
- A small synthetic project that contains no proprietary source or secrets
Tool Discipline
Use Read, Glob, and Grep to establish the application entrypoint, package versions, and existing lifecycle ownership. Use WebFetch only for current official StackBlitz or WebContainers documentation. Use Write or Edit for a user-requested smoke-test implementation after inspection.
Current Contract
WebContainer.boot()is expensive and permits only one concurrent instance; centralize ownership.mount()accepts aFileSystemTreeor supported binary snapshot and copies it into the virtual filesystem.- Check a spawned install process through its
exitpromise before starting the server. - Register
server-ready,error, and cleanup handlers before relying on a preview URL; retain the unsubscribe functions. - Use the URL emitted by
server-readyrather than constructing a preview host.
Authentication
The smoke test must not contain API keys, registry tokens, cookies, or .env data. If commercial API-key configuration or organization auth is required, consume the existing runtime binding and initialization module without displaying its value or duplicating the flow.
Workflow
- Confirm the current package and browser support assumptions from repository evidence.
- Reuse or create a singleton owner for the WebContainer instance.
- Define a tiny synthetic project with a locked dependency set and explicit start script.
- Mount the tree, spawn the repository-approved install command, stream bounded status output, and fail on a nonzero exit.
- Subscribe to readiness and error events, start the server, and attach the emitted URL to the intended preview element.
- Record cleanup behavior for listeners, processes, and
teardown()when the owning view is permanently disposed.
Show full SKILL.md (173 more words)Show less
Approval Boundaries
Do not add arbitrary user source, private packages, production secrets, telemetry, or broad network access to the smoke test without explicit authorization and a security review. Do not alter production isolation headers merely to make a local example pass.
Output
Return the exact test surface, package and header evidence, lifecycle owner, expected state sequence, bounded logs, preview readiness result, cleanup path, and any environment-specific limitation.
Error Handling
| Condition | Response |
|---|---|
| A second boot path exists | Stop and consolidate lifecycle ownership before testing. |
| Install exits nonzero | Preserve the exit code and bounded output; do not blindly retry. |
| Preview never becomes ready | Check process exit and port/error events before changing ports. |
| Test needs real customer code | Replace it with a synthetic fixture and report the missing contract separately. |
Examples
For a Vite host, mount a two-file synthetic Node project, wait for a successful install exit, start its server, and verify the server-ready URL in one supported browser without committing any generated dependency tree.
Resources
© jeremylongshore, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file (references) in skills/.curated/stackblitz-hello-world of jeremylongshore/tons-of-skills-marketplace.
- SKILL.md
- references/official-docs.md
Open the folder on GitHubat commit cfae287
Compare with similar skills
Stackblitz Hello World 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 |
|---|---|---|---|---|---|---|
| Stackblitz Hello World this skilljeremylongshore/tons-of-skills-marketplace | 2.8k | — | ~1.1k | Automated safety check: Notes | MIT | |
| Reproduce Chat Statesdifferent-ai/openwork | 24k | — | ~673 | Automated safety check: Pass | Custom licence | |
| Dynamo Jira TicketDynamoDS/Dynamo | 2k | — | ~1.1k | Automated safety check: Pass | Apache-2.0 | |
| Moav E2EMotherofallVPNs/MoaV | 449 | — | ~1.9k | Automated safety check: Notes | MIT | |
| Creating A Coral TaskHuman-Agent-Society/CORAL | 1.1k | — | ~2.2k | Automated safety check: Pass | Apache-2.0 | |
| Launch Rlmarin-community/marin | 3.9k | — | ~894 | Automated safety check: Pass | Apache-2.0 |
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Moav E2E
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Run and debug MoaV's end-to-end tests — real protocol connectivity (client-test.sh) and the moav CLI smoke test — against a LIVE server, via the self-hosted e2e workflow or a local test VPS.
Creating A Coral Task
Human-Agent-Society/CORAL
Author a new CORAL task — the three pieces that must line up (task.yaml, seed/, a packaged grader/), the coral init → coral validate → smoke-test loop, and how to pick a grader pattern (stdout…
Launch Rl
marin-community/marin
Define, validate, submit, or restart a Marin SkyRL experiment through its artifact main.
Actionbook Web Test
actionbook/actionbook
Run browser-based web tests against websites using Actionbook CLI.
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Related
Categories
Questions about Stackblitz Hello World
What does Stackblitz Hello World do?
Build a minimal, controlled WebContainer smoke test that boots once, mounts a small project, observes process exit, and captures the preview URL. Stackblitz Hello World is an agent skill from jeremylongshore/tons-of-skills-marketplace. Build a minimal, controlled WebContainer smoke test that boots once, mounts a small project, observes process exit, and captures the preview URL.
When should I use Stackblitz Hello World?
Stackblitz Hello World fits situations like: proving browser/runtime compatibility before building a larger in-browser development experience; with StackBlitz hello world; test WebContainers; run Node in the browser.
How do I install Stackblitz Hello World in Claude Code?
Run `npx skills add jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a claude-code`. Or copy the skill folder (skills/.curated/stackblitz-hello-world in jeremylongshore/tons-of-skills-marketplace) into .claude/skills/stackblitz-hello-world in your project. Claude Code loads it when a task matches its description.
How do I install Stackblitz Hello World in Codex?
Run `npx skills add jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a codex`. Or copy the skill folder (skills/.curated/stackblitz-hello-world in jeremylongshore/tons-of-skills-marketplace) into .agents/skills/stackblitz-hello-world in your project. Codex loads it when a task matches its description.
Can I use Stackblitz Hello World in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add jeremylongshore/tons-of-skills-marketplace --skill stackblitz-hello-world -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/stackblitz-hello-world, .gemini/skills/stackblitz-hello-world, .github/skills/stackblitz-hello-world and .opencode/skills/stackblitz-hello-world in your project.
What does Stackblitz Hello World need to run?
SKILL.md names no scripts, command-line tools or credentials: Stackblitz Hello World is instructions for the agent only. Its frontmatter pre-approves these tools: Read, Glob, Grep, WebFetch, Write, Edit. Compatibility (from SKILL.md): Designed for Claude Code.
Does Stackblitz Hello World access the network?
SKILL.md names 1 domain. As links in the text: webcontainers.io. This is read from the text; nothing was executed.
Is Stackblitz Hello World safe to install?
Our automated static check of SKILL.md found notes only (mentions a .env file), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.
What licence does Stackblitz Hello World use?
Stackblitz Hello World is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Stackblitz Hello World use?
About 1.1k tokens (SKILL.md is roughly 4.4k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 246 tokens, read only when the agent opens those files.
What are the alternatives to Stackblitz Hello World?
Skills that share tags, products or a category with Stackblitz Hello World: Reproduce Chat States (different-ai/openwork, 24k stars), Dynamo Jira Ticket (DynamoDS/Dynamo, 2k stars), Moav E2E (MotherofallVPNs/MoaV, 449 stars) and Creating A Coral Task (Human-Agent-Society/CORAL, 1.1k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Stackblitz Hello World?
jeremylongshore (a GitHub user) maintains it in jeremylongshore/tons-of-skills-marketplace, which has 2,827 GitHub stars. The repository holds 3,342 skills in this directory. The repository was last updated on October 10, 2026.
Source: jeremylongshore/tons-of-skills-marketplace on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.