cloud-storage-web

A guide for using the CloudBase web SDK to upload, download, delete, and manage files in cloud storage. Cloud storage is an online place for storing files separately from the application's code and database.

In plain words
What is it for?
Use it for browser-based CloudBase file uploads, downloads, temporary file URLs, and file management.
Why use it?
It helps avoid mistakes involving file APIs, temporary download links, security domains, and browser authentication.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/tencentcloudbase/cloudbase-skills/cloud-storage-web
Any agent
npx skills add TencentCloudBase/cloudbase-skills --skill cloud-storage-web
Clone the repo
git clone --depth 1 https://github.com/TencentCloudBase/cloudbase-skills

Made for: Claude Code, Codex.

Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,542 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00035 $0.03542
Opus 5 $0.00017 $0.01771
Sonnet 5 $0.00007 $0.00708
Haiku 4.5 $0.00003 $0.00354

Measured today against content hash 5dcf4f2c34f9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cloud-storage-web 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 today.

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.

Origin

This is a copy

100% identical to cloud-storage-web — 2 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/cloudbase/references/cloud-storage-web/SKILL.md · 310 lines

How it starts

The opening of the file, as written. The whole thing — 310 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Sibling skills (local only)

Sibling CloudBase skills ship beside this skill. Use local relative paths such as ../auth-tool-cloudbase/SKILL.md.

If a referenced sibling skill file is missing from this environment, ask the user to install the full CloudBase plugin (or the missing skill). Do not HTTP-fetch remote skill or protocol markdown into the agent context.

Cloud Storage Web SDK

Activation Contract

Use this first when

  • A browser or Web app must upload, download, or manage CloudBase storage objects through @cloudbase/js-sdk.
  • The request mentions uploadFile, getTempFileURL, deleteFile, or downloadFile in frontend code.

Read before writing code if

  • The task is browser-side storage work but you still need to separate it from Mini Program storage, backend storage management, or static hosting deployment.
  • The request may be blocked by security domains or frontend auth.

Then also read

  • Web login and identity -> ../auth-web-cloudbase/SKILL.md
  • General Web app setup -> ../web-development/SKILL.md
  • Direct storage management through MCP tools -> ../cloudbase-platform/SKILL.md

Do NOT use for

  • Mini Program file APIs.
  • Backend or agent-side direct storage management through MCP.
  • Static website hosting deployment via manageHosting(action="upload").
  • Database operations.

Common mistakes / gotchas

  • Uploading from browser code without configuring security domains.
  • Using this skill for static hosting instead of storage objects.
  • Mixing browser SDK upload flows with server-side file-management tasks.
  • Assuming temporary download URLs are permanent links.
  • Ignoring STORAGE_NOT_EXIST; it means the target storage bucket/resource is not ready, not that the browser upload code should fabricate a URL.
  • On local Vite or dev-server tasks, forgetting to whitelist the exact current browser host:port before testing app.uploadFile().
  • Treating CloudBase PG / pgstore like the legacy NoSQL CloudBase storage. PG environments use a separate pgstore backend whose buckets are NOT auto-created from your old NoSQL bucket. If pgstore has no bucket, every upload returns STORAGE_BUCKET_NOT_FOUND and the SDK then issues PUT https://undefined/ (visible in DevTools as net::ERR_NAME_NOT_RESOLVED). Treat bucket existence as a hard prerequisite, just like Supabase: in Supabase Storage every upload must target an already-created bucket; CloudBase PG follows the same model.

Read the full file on GitHub · 310 lines

Changes

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.

  1. today Changed 5dcf4f2c34f9
  2. 2d ago First seen · 310 lines · 35 tokens per session scan A fd8935f8abd2

Subscribe to this mod's changes

cloud-storage-web is a skill published in the GitHub repository TencentCloudBase/cloudbase-skills (30 stars, last pushed yesterday), licensed MIT. It adds 35 tokens to every session and 3,542 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to cloud-storage-web, differing in 2 lines, and is treated as a copy.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

brainstorming

You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.

obra/superpowers · 37 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

agent-host-chat-contributions

Build and review cross-cutting agent-host chat behavior through lifecycle contributions. Use when adding turn lifecycle side effects, prompt or context injection, restored-history transformation, protocol-action observation, or when reviewing changes that add code to AgentSideEffects or AgentService.

microsoft/vscode · 56 tokens

auto-perf-optimize

Run agent-driven VS Code performance or memory investigations. Use when asked to launch Code OSS, automate a VS Code scenario, run the Chat memory smoke runner, capture renderer heap snapshots, take workflow screenshots, compare run summaries, or drive a repeatable scenario before heap-snapshot analysis.

microsoft/vscode · 62 tokens