file-storage-design SKILL.md skillA
file-storage-design from amey-thakur/ai-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add amey-thakur/ai-skills/file-storage-design@git:20260720.1dc980ePins git:20260720.1dc980e in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- amey-thakur/ai-skills
- Path
skills/backend/file-storage-design/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260720.1dc980e, committed Jul 20, 2026
- Size
- 2,875 bytes
- Repository stars
- 14
- License
- MIT
Store user files in object storage with presigned transfers, validation, and lifecycle rules. Use when building upload/download features or moving file handling off application servers.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# File storage design
Files go to object storage; your servers handle authorization and
metadata, never the bytes. Every design decision follows from keeping
payloads off your request path.
## Method
1. **Presign uploads, direct to the bucket.** Client asks your API for
an upload URL; you authorize, generate a presigned PUT (or POST
policy) scoped to one key, content-type, size limit, and short
expiry; client uploads directly. Your API never proxies bytes, so
uploads cannot exhaust your workers.
2. **Own the keys, never trust filenames.** Server generates the object
key (`tenant/{id}/uploads/{uuid}`); the user's filename is metadata,
stored and returned as Content-Disposition. User-controlled paths are
traversal and overwrite attacks waiting (see path-traversal-defense).
3. **Verify after upload, before use.** A confirm endpoint (or bucket
event) checks the object exists, size matches, magic bytes match the
declared type (not the extension), then flips DB status to `ready`
and enqueues scanning/thumbnailing as jobs. Files never referenced by
a confirm get lifecycle-deleted (abandoned uploads are storage cost).
…Read the whole file at its exact version.
How to install
mdr add amey-thakur/ai-skills/file-storage-design@sha256:b6e6ca5a89a22da9The line at the top of this page pins the label git:20260720.1dc980e, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ustkkz7bn4lsxbxl)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Jul 20, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (2875 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
amey-thakur/ai-skills · 14 stars · license MIT · pushed 2026-09-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ustkkz7bn4lsxbxl GET https://markdownregistry.com/api/v1/resolve?ref=amey-thakur/ai-skills/file-storage-design GET https://markdownregistry.com/api/v1/blob/b6e6ca5a89a22da9e6ae602d691128a5c6f84892c0564f84e2c96074d20ee5f2
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.