DESIGN.md@challenge/v7A
DESIGN.md@challenge/v7 from qybaihe/bla is a DESIGN.md file: the design rules coding agents follow in that repo.
mdr add qybaihe/bla/challenge/v7/DESIGN.md@git:20261031.1967946Pins git:20261031.1967946 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 14 of 14 checks passed
- Kind
- DESIGN.md file
- Repository
- qybaihe/bla
- Path
challenge/v7/DESIGN.md- Versions recorded
- 2
- Latest version
- git:20261031.1967946, committed Oct 31, 2026
- First version recorded
- Oct 31, 2026
- Size
- 6,763 bytes
- Repository stars
- 2,353
- License
- MIT
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
# CrackMe v7 — Meridian Design
> Status: **successor to CrackMe v6**. v6 (harden-native vault) shipped in
> bla-agents 1.6.1 as an interim snapshot and is retained under
> `challenge/v6/` for history; it is **not** the product challenge anymore.
## Product framing
Meridian is a small offline engineering calculator:
| Command | Behavior |
|---|---|
| `calc <expr>` | recursive-descent expression engine (`+ - * / % ^ !`, functions, constants) |
| `convert <v> <from> <to>` | unit conversion via `data/catalog.json` |
| `stats <n…>` | descriptive statistics |
| `units` / `version` | catalog / version |
| `license activate <KEY>` | Meridian Pro activation |
The public prize is the **activation certificate** printed on success. The
challenge never uses the word "flag" in product copy, so AI reverse agents
are not steered by CTF vocabulary. Secrets are product mechanisms
(revision digest + sealed certificate in the unit catalog), not an obvious
`FLAG{…}` gate.
## Why v6 failed (requirements this design answers)
Owner writeup against v6, mapped to design constraints:
| Critique | v7 response |
|---|---|
…Read the whole file at its exact version.
How to install
mdr add qybaihe/bla/challenge/v7/DESIGN.md@sha256:01846f5f95af5e10The line at the top of this page pins the label git:20261031.1967946, 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_hzijt4ejc4eyvvh7)
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Versions
The registry has recorded 2 versions of this file, all committed on Oct 31, 2026.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261031.1967946 latest | 2026-10-31 | 1967946 | 6,763 B | A | view · diff |
| git:20261031.e621d8e | 2026-10-31 | e621d8e | 6,771 B | A | view |
Audit of the latest version
- pass: Size between 200 bytes and 200 KB (6763 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
qybaihe/bla · 2,353 stars · license MIT · pushed 2026-11-05 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_hzijt4ejc4eyvvh7 GET https://markdownregistry.com/api/v1/resolve?ref=qybaihe/bla/challenge/v7/DESIGN.md GET https://markdownregistry.com/api/v1/blob/01846f5f95af5e109d9e0c1d46fca38f5cf609306805eebb7ccd0cd57cbc6c0a
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: what DESIGN.md is and how agents use it · which agent file does what.