Worker Capability Catalog
HarnessMD/munder-difflin
Read-only catalog that tells a spawned worker agent its environment variables, temporal date-range skills and how to call each integration.
A skill your agent uses when adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections.
MITAuto-check passed
Install Offline Fallback
$ npx skills add thedaviddias/Front-End-Checklist --skill offline-fallback -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offline-fallback --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/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/offline-fallback .claude/skills/offline-fallback && 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 "offline-fallback" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offline-fallback into .claude/skills/offline-fallback/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offline-fallback", 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/thedaviddias/Front-End-Checklist/tree/main/skills/offline-fallbackType 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 thedaviddias/Front-End-Checklist --skill offline-fallback -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offline-fallback --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/offline-fallback .agents/skills/offline-fallback && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "offline-fallback" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offline-fallback into .agents/skills/offline-fallback/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offline-fallback", 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 thedaviddias/Front-End-Checklist --skill offline-fallback -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offline-fallback --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/offline-fallback .cursor/skills/offline-fallback && 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 "offline-fallback" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offline-fallback into .cursor/skills/offline-fallback/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offline-fallback", 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/thedaviddias/Front-End-Checklist.git --path skills/offline-fallback--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 thedaviddias/Front-End-Checklist --skill offline-fallback -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offline-fallback --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/offline-fallback .gemini/skills/offline-fallback && 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 "offline-fallback" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offline-fallback into .gemini/skills/offline-fallback/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offline-fallback", 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 thedaviddias/Front-End-Checklist offline-fallbackInstalls 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 thedaviddias/Front-End-Checklist --skill offline-fallback -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/offline-fallback .github/skills/offline-fallback && 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 "offline-fallback" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offline-fallback into .github/skills/offline-fallback/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offline-fallback", 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 thedaviddias/Front-End-Checklist --skill offline-fallback -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install thedaviddias/Front-End-Checklist offline-fallback --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/thedaviddias/Front-End-Checklist.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/offline-fallback .opencode/skills/offline-fallback && 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 "offline-fallback" agent skill from https://github.com/thedaviddias/Front-End-Checklist/tree/main/skills/offline-fallback into .opencode/skills/offline-fallback/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "offline-fallback", 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
offline-fallback- GitHub stars
- 74k
- Token cost
- ~488 tokens
- SKILL.md length
- 222 words
- Files
- 2 (incl. references)
- Skills in repo
- 390
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections.
- Adding PWA capabilities
- SKILL.md covers Quick Reference, Check, Fix and Explain, plus 1 more section
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Implementing a service worker
What it does
Offline Fallback is an agent skill from thedaviddias/Front-End-Checklist. Use when adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections.
Its SKILL.md is about 490 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/rule.md`).
The repository describes itself as: 🗂 The essential checklist for modern web development, for humans and AI agents. The licence is MIT.
When your agent uses it
- Adding PWA capabilities
- Implementing a service worker
- Improving the experience for users on unreliable network connections
Example prompts
- “/offline-fallback”
What it can do on your machine
Read from SKILL.md and the folder at commit e8d14d0. It shows what the files ask for, not the result of running them.
Tool permissions
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.
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):
frontendchecklist.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.
Context cost
Offline Fallback loads about 488 tokens when it runs, and up to ~2.4k if it reads all its reference files. Until then it costs about 39 tokens; SKILL.md has 222 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 passed
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.
SKILL.md
The full file from thedaviddias/Front-End-Checklist at commit e8d14d0, republished under its MIT licence (© thedaviddias). 222 words, ~488 tokens.
Download SKILL.mdSave it as
.claude/skills/offline-fallback/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- offline-fallback
- description
- Use when adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections.
- metadata.category
- performance
- metadata.priority
- low
- metadata.difficulty
- beginner
- metadata.estimatedTime
- 20
- metadata.source
- frontendchecklist.io
- metadata.url
- https://frontendchecklist.io/rules/performance/offline-fallback
Provide an offline fallback page
The browser's default offline error screen ("No internet connection") is confusing and completely outside your brand. A custom offline page maintains the user experience, reinforces trust, and can surface cached content or useful actions — such as enabling users to continue reading a cached article or queuing a form submission for later.
Quick Reference
- Create a minimal /offline HTML page that works without any network requests
- Pre-cache the offline page during the service worker install event
- Intercept failed navigation requests and serve the offline page instead
- Include helpful guidance so users know what to do while offline
Check
Check whether the site shows a custom offline fallback page when the network is disconnected and a navigation request cannot be fulfilled.
Fix
Create a self-contained /offline page and configure the service worker to pre-cache it and serve it for failed navigation requests.
Explain
Explain how a service worker can intercept failed network requests and return a cached offline fallback page to the user.
Code Review
Review the service worker fetch handler and the offline page markup. Verify the offline page is pre-cached at install time, that it does not depend on external resources, and that the fallback is only served for navigation requests (not sub-resources).
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/rules/performance/offline-fallback
© thedaviddias, 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/offline-fallback of thedaviddias/Front-End-Checklist.
- SKILL.md
- references/rule.md
Open the folder on GitHubat commit e8d14d0
Compare with similar skills
Offline Fallback 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 |
|---|---|---|---|---|---|---|
| Offline Fallback this skillthedaviddias/Front-End-Checklist | 74k | — | ~488 | Automated safety check: Pass | MIT | |
| Worker Capability CatalogHarnessMD/munder-difflin | 8.6k | — | ~1.4k | Automated safety check: Notes | MIT | |
| Product Capabilityaffaan-m/ECC | 275k | 2 repos | ~1.1k | Automated safety check: Pass | MIT | |
| Worker Visualizernexu-io/open-design | 100k | — | ~998 | Automated safety check: Pass | Apache-2.0 | |
| Agent Worker Specialistruvnet/ruflo | 74k | 3 repos | ~1.4k | Automated safety check: Pass | MIT | |
| Loop Workerruvnet/ruflo | 74k | — | ~297 | Automated safety check: Pass | MIT |
Similar skills
Product Capability
affaan-m/ECC
Translate PRD intent, roadmap asks, or product discussions into an implementation-ready capability plan that exposes constraints, invariants, interfaces, and unresolved decisions before…
Worker Visualizer
nexu-io/open-design
A real-time data/particle/simulation visualizer whose heavy compute runs in a Web Worker (off the main thread), optionally sharing memory with the UI via SharedArrayBuffer, and renders to a canvas…
Agent Worker Specialist
ruvnet/ruflo
Agent skill for worker-specialist - invoke with $agent-worker-specialist
Loop Worker
ruvnet/ruflo
Run Ruflo background workers using Claude Code native /loop scheduling
Artifact Capabilities
asgeirtj/system_prompts_leaks
Runtime capabilities a published Artifact page can be granted — behavior static HTML cannot provide on its own, such as the page reading live or connected data, remembering what people do on it (a…
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Questions about Offline Fallback
What does Offline Fallback do?
A skill your agent uses when adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections. Offline Fallback is an agent skill from thedaviddias/Front-End-Checklist. Use when adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections.
When should I use Offline Fallback?
Offline Fallback fits situations like: adding PWA capabilities; implementing a service worker; improving the experience for users on unreliable network connections.
How do I install Offline Fallback in Claude Code?
Run `npx skills add thedaviddias/Front-End-Checklist --skill offline-fallback -a claude-code`. Or copy the skill folder (skills/offline-fallback in thedaviddias/Front-End-Checklist) into .claude/skills/offline-fallback in your project. Claude Code loads it when a task matches its description.
How do I install Offline Fallback in Codex?
Run `npx skills add thedaviddias/Front-End-Checklist --skill offline-fallback -a codex`. Or copy the skill folder (skills/offline-fallback in thedaviddias/Front-End-Checklist) into .agents/skills/offline-fallback in your project. Codex loads it when a task matches its description.
Can I use Offline Fallback 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 thedaviddias/Front-End-Checklist --skill offline-fallback -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/offline-fallback, .gemini/skills/offline-fallback, .github/skills/offline-fallback and .opencode/skills/offline-fallback in your project.
What does Offline Fallback need to run?
SKILL.md names no scripts, command-line tools or credentials: Offline Fallback is instructions for the agent only.
Does Offline Fallback access the network?
SKILL.md names 1 domain. As links in the text: frontendchecklist.io. This is read from the text; nothing was executed.
Is Offline Fallback safe to install?
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.
What licence does Offline Fallback use?
Offline Fallback is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Offline Fallback use?
About 488 tokens (SKILL.md is roughly 2k 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 1.9k tokens, read only when the agent opens those files.
What are the alternatives to Offline Fallback?
Skills that share tags, products or a category with Offline Fallback: Worker Capability Catalog (HarnessMD/munder-difflin, 8.6k stars), Product Capability (affaan-m/ECC, 275k stars), Worker Visualizer (nexu-io/open-design, 100k stars) and Agent Worker Specialist (ruvnet/ruflo, 74k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Offline Fallback?
thedaviddias (a GitHub user) maintains it in thedaviddias/Front-End-Checklist, which has 74,398 GitHub stars. The repository holds 390 skills in this directory. The repository was last updated on October 6, 2026.
Source: thedaviddias/Front-End-Checklist on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.