r2-upload is a skill in zebbern/claude-code-guide, last changed 29 Oct 2026. It can install more skills, run shell commands, reach the network, name web addresses and bundle scripts — read the findings before installing.
Upload files to Cloudflare R2, AWS S3, or any S3-compatible storage (like MinIO) and generate secure, time-limited presigned download links with configurable expiration, typically set to 5 minutes. Use when the user needs to upload a file to cloud storage and get a shareable link, or mentions R2, S3, presigned URLs, temporary links, or file uploads with expiration.
At a glance
What it can touch
How much a skill can do, not whether it is risky.
Pattern check
Nothing flagged
That isn't proof the skill is harmless.
Commit 2b927dd · 3 Nov 2026
How the check worksPattern check: nothing flagged
That isn't proof the skill is harmless.
Install
Each tab says whether it installs commit 2b927dd, the one we checked, or the latest version.
OpenCode also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
Goose also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
Windsurf (Devin Desktop) also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
Zed also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
Roo Code also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
Factory Droid also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
Junie also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
Amp also looks in .agents/skills/ and ~/.agents/skills/, so use the Any agent steps.
No install command here reaches Kiro. Copy the skill's folder into .kiro/skills/ in your project, or ~/.kiro/skills/ for all your projects. zebbern/claude-code-guide/skills/r2-upload (opens in a new tab)
Antigravity also looks in .agents/skills/, so the Any agent steps reach it with This project. For All projects, see where Antigravity looks.
Cline also looks in .claude/skills/, so the Claude Code steps reach it with This project. For All projects, see where Cline looks.
Claude Code
Pinned to commit 2b927dd, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/zebbern/claude-code-guide.git "$tmp" &&git -C "$tmp" fetch -q --depth 1 origin 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&git -C "$tmp" sparse-checkout set -- skills/r2-upload &&git -C "$tmp" checkout -q 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&mkdir -p .claude/skills &&mkdir .claude/skills/r2-upload &&cp -R "$tmp"/skills/r2-upload/. .claude/skills/r2-upload/ &&rm -rf "$tmp"If Claude Code was already running and this created the skills folder, run /reload-skills.
Claude apps
Pinned to commit 2b927dd, the one we checked.
Skills in the Claude apps belong to your account rather than to a project.
Make r2-upload.zip, with the skill folder at the top level:
tmp="$(mktemp -d)" &&git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/zebbern/claude-code-guide.git "$tmp" &&git -C "$tmp" fetch -q --depth 1 origin 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&git -C "$tmp" sparse-checkout set -- skills/r2-upload &&git -C "$tmp" checkout -q 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&out="$(mktemp -d)" &&cp -R "$tmp"/skills/r2-upload "$out"/r2-upload &&(cd "$out" && zip -qr - r2-upload) > r2-upload.zip &&rm -rf "$tmp" "$out"In Claude, open Customize > Skills, select +, then + Create skill > Upload a skill, and choose r2-upload.zip.
On Free, Pro and Max plans, turn on Code execution and file creation (Create and edit files in newer settings) under Settings > Capabilities.
Codex
Pinned to commit 2b927dd, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/zebbern/claude-code-guide.git "$tmp" &&git -C "$tmp" fetch -q --depth 1 origin 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&git -C "$tmp" sparse-checkout set -- skills/r2-upload &&git -C "$tmp" checkout -q 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&mkdir -p .agents/skills &&mkdir .agents/skills/r2-upload &&cp -R "$tmp"/skills/r2-upload/. .agents/skills/r2-upload/ &&rm -rf "$tmp"Codex picks up new skills on its own; restart it if this one does not appear.
Cursor
Pinned to commit 2b927dd, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/zebbern/claude-code-guide.git "$tmp" &&git -C "$tmp" fetch -q --depth 1 origin 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&git -C "$tmp" sparse-checkout set -- skills/r2-upload &&git -C "$tmp" checkout -q 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&mkdir -p .cursor/skills &&mkdir .cursor/skills/r2-upload &&cp -R "$tmp"/skills/r2-upload/. .cursor/skills/r2-upload/ &&rm -rf "$tmp"Copilot & VS Code
Pinned to commit 2b927dd, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/zebbern/claude-code-guide.git "$tmp" &&git -C "$tmp" fetch -q --depth 1 origin 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&git -C "$tmp" sparse-checkout set -- skills/r2-upload &&git -C "$tmp" checkout -q 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&mkdir -p .github/skills &&mkdir .github/skills/r2-upload &&cp -R "$tmp"/skills/r2-upload/. .github/skills/r2-upload/ &&rm -rf "$tmp"In a running Copilot CLI session, run /skills reload.
Or install it with gh skill, which also installs the commit we checked. Needs GitHub CLI 2.90 or later.
gh skill install zebbern/claude-code-guide skills/r2-upload/SKILL.md@2b927dd838f8744ea8d8e9b18edc550d03aee503 --agent github-copilot --scope projectGemini CLI
Pinned to commit 2b927dd, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/zebbern/claude-code-guide.git "$tmp" &&git -C "$tmp" fetch -q --depth 1 origin 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&git -C "$tmp" sparse-checkout set -- skills/r2-upload &&git -C "$tmp" checkout -q 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&mkdir -p .gemini/skills &&mkdir .gemini/skills/r2-upload &&cp -R "$tmp"/skills/r2-upload/. .gemini/skills/r2-upload/ &&rm -rf "$tmp"In a running session, run /skills reload.
Or use Gemini CLI’s own installer. Installs the latest version, not the one we checked.
gemini skills install https://github.com/zebbern/claude-code-guide.git --path skills/r2-upload --scope workspaceAny agent
Pinned to commit 2b927dd, the one we checked.
OpenCode, Goose, Windsurf (Devin Desktop), Zed, Roo Code, Factory Droid, Junie, Amp and Antigravity read .agents/skills in a project.
From your project's root folder:
tmp="$(mktemp -d)" &&git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/zebbern/claude-code-guide.git "$tmp" &&git -C "$tmp" fetch -q --depth 1 origin 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&git -C "$tmp" sparse-checkout set -- skills/r2-upload &&git -C "$tmp" checkout -q 2b927dd838f8744ea8d8e9b18edc550d03aee503 &&mkdir -p .agents/skills &&mkdir .agents/skills/r2-upload &&cp -R "$tmp"/skills/r2-upload/. .agents/skills/r2-upload/ &&rm -rf "$tmp"Or use the skills CLI from skills.sh. Installs the latest version, not the one we checked. The skills CLI reports installs to skills.sh unless you set DISABLE_TELEMETRY=1.
npx skills@1.7.4 add zebbern/claude-code-guide --skill r2-uploadWhat it can touch
From the files and frontmatter at commit 2b927dd. This is how much a skill can do, not whether it is risky.
Pattern check
Pattern check: nothing flagged · commit 2b927dd · 3 Nov 2026
We checked every text file in this skill, at commit 2b927dd on 3 Nov 2026, against 45 published patterns such as download-and-run commands, hidden text and credential access. We don't run the skill, we don't read the web pages it points to, and we can't judge everything its instructions might lead an agent to do. In published tests, pattern checks like this one missed most malicious skills. Read the skill before you install it — especially anything it asks you to download or run.
How the check worksReport an incorrect finding
Outside links we did not follow
- https://abc123.r2.cloudflarestorage.com
- https://xyz789.r2.cloudflarestorage.com
- https://dash.cloudflare.com/
- https://s3.us-east-1.amazonaws.com
- https://dash.cloudflare.com
- https://files.yourdomain.com
- https://YOUR_ACCOUNT_ID.r2.cloudflarestorage.com
- https://github.com/clawdbot/clawdhub-skills
- https://clawdhub.com/skills/r2-upload
- https://$
Show 1 more
- https://s3.$
Format check
Each agent reads SKILL.md a little differently. We check the file against each one's published rules; we don't run the skill in any agent.
Agent Skills specPasses with warnings
The open format from agentskills.io, held to the strictest version of each rule among the agents we check.
- Warning
Fields outside the spec: summary. Uploads to the Claude apps and API, and the spec's validator, reject the file; most agents ignore these fields. O1
Fix: Delete them for a portable skill, or keep them if you only target the agents that read them.
- Note
There is no license field, so readers can't tell whether they may reuse the skill. O2
Fix: Add license: with an SPDX name such as MIT or Apache-2.0, or the name of a bundled licence file.
- Note
Reference files that SKILL.md doesn't link: SECURITY.md. Anthropic suggests linking every reference file directly from SKILL.md. B4
Fix: Link each one from SKILL.md and say when to read it.
- Note
Reference files over 100 lines with no table of contents at the top: SECURITY.md (153 lines). B5
Fix: Add a short list of the sections at the top of each.
- Warning
Claude CodePasses
Claude Code reads its own extra fields, ignores unknown ones, and still loads a skill whose frontmatter is broken, without its fields.
- Note
Claude Code ignores fields it doesn't know: summary. O1
Fix: Check the spelling against Claude Code's field list, or delete them.
- Note
Reference files that SKILL.md doesn't link: SECURITY.md. Anthropic suggests linking every reference file directly from SKILL.md. B4
Fix: Link each one from SKILL.md and say when to read it.
- Note
Reference files over 100 lines with no table of contents at the top: SECURITY.md (153 lines). B5
Fix: Add a short list of the sections at the top of each.
- Note
Claude apps & API uploadFails
Uploading to claude.ai or the Claude API, or packaging with Anthropic's script, accepts only the six spec fields and stops on anything else.
- Error
Upload and packaging fail on fields outside the spec: summary. O1
Fix: Delete them, and keep your own data under metadata as text values.
- Note
The description is 367 characters. The claude.ai Help Center says 200 at most, though Anthropic's API docs and validator allow 1,024. D4
Fix: If the claude.ai upload refuses it, trim the description to 200 characters.
- Note
Reference files that SKILL.md doesn't link: SECURITY.md. Anthropic suggests linking every reference file directly from SKILL.md. B4
Fix: Link each one from SKILL.md and say when to read it.
- Note
Reference files over 100 lines with no table of contents at the top: SECURITY.md (153 lines). B5
Fix: Add a short list of the sections at the top of each.
- Error
OpenAI (Codex & API)Passes with warnings
Codex finds SKILL.md by its exact name and needs a description; OpenAI's Skills API checks the frontmatter against the spec and caps uploads.
- Warning
Fields outside the spec: summary. Codex ignores them; OpenAI doesn't say whether its upload accepts them. O1
Fix: Delete them, or move your own data under metadata as text values.
- Warning
VS Code & CopilotPasses
VS Code reads skills one folder below .github/skills, .claude/skills or .agents/skills and falls back to the folder name when the name is missing or differs; GitHub's Copilot docs require the exact name SKILL.md.
- Note
VS Code ignores fields it doesn't support: summary. O1
Fix: Delete them unless another agent you target reads them.
- Note
SKILL.md
Files
9 files
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