backend-files skillA
backend-files is agent-read markdown (skill) from bekaku/java-spring-boot-starter: Use when a change reads, writes, deletes, lists, uploads, downloads, streams, or serves files — FileManager/FilesDirectory endpoints, CDN/public paths, chunked upload and merge, HTTP Range streaming, image processing, or any filesystem path handling — in this Spring Boot backend..
Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.
What the file says
# Backend Files — Playbook
> **Role:** HOW to change file handling safely. Binding facts + evidence: `skills/backend/FILES.md` (read it too).
> **Requires:** `backend-core`. **Usually paired with:** `backend-security` (ownership), `backend-data` (metadata), `backend-testing`.
## Know this first
- The upload root **is** the public `/cdn/**` root. Anything saved there is downloadable without login.
- DB rollback does not undo file writes or deletes.
- Path containment only proves "inside the root", not "belongs to this user".
## Recipe A — store a new kind of file
1. Decide: public (served via `/cdn/**`) or private. Private files must not be reachable through `/cdn/**`; serve them through an authenticated, owner-checked endpoint.
2. Generate the filename on the server; build the path from the configured root; verify containment after resolving.
3. Order the steps and define cleanup:
```text
write file to final path
→ save FileManager row (@Transactional service method)
→ if the save fails: delete the written file (log, do not swallow)
```
4. Record the owner (`created_user` via audit, or an explicit owner id from `auth.getId()`).
…Read the whole file at its exact version.
How to install
mdr add bekaku/java-spring-boot-starter/backend-files@git:20260924.15dc64amdr add bekaku/java-spring-boot-starter/backend-files@sha256:ecfa1f73279a1b0ePin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.
[](https://markdownregistry.com/a/art_otye3hnc7nzuhh6i)
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Versions
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260924.15dc64a latest | 2026-09-24 | 15dc64a | 3,444 B | A | view · diff |
| git:20260923.b5acb6d | 2026-09-23 | b5acb6d | 1,985 B | A | view · diff |
| git:20260921.de5eb9f | 2026-09-21 | de5eb9f | 1,207 B | A | view |
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 (3444 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
bekaku/java-spring-boot-starter · 31 stars · license none · pushed 2026-09-24 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_otye3hnc7nzuhh6i GET https://markdownregistry.com/api/v1/resolve?ref=bekaku/java-spring-boot-starter/backend-files GET https://markdownregistry.com/api/v1/blob/ecfa1f73279a1b0e8f326e05472b6e7a0447cd682ccc5c8d00c3149089ece4d2
Your agent 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.