ost-builder SKILL.md skillA
ost-builder from haabe/mycelium is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add haabe/mycelium/ost-builder@git:20261106.598445dPins git:20261106.598445d in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- haabe/mycelium
- Path
plugins/mycelium/skills/ost-builder/SKILL.md- Versions recorded
- 24
- Latest version
- git:20261106.598445d, committed Nov 6, 2026
- First version recorded
- Jul 4, 2026
- Size
- 19,799 bytes
- Repository stars
- 51
- License
- MIT
Use to build or update an Opportunity Solution Tree from research data. Never from brainstorming.
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
# OST Builder Skill Build and maintain Opportunity Solution Trees from research evidence. ## Preflight: Read target canvas file(s) before any Write/Edit **Hard rule.** Before issuing `Write` or `Edit` against any `.claude/canvas/*.yml`, use the **Read tool** on that file in this session. Claude Code's Read-before-Write check requires the `Read` tool specifically — `cat`/`head`/`grep` via Bash do NOT satisfy it. **Edit vs Write — different cost profiles** (verified 2026-05-14): - **`Edit`** (exact-string replacement): `Read` with `limit: 1` satisfies the check at ~50 tokens. State-tracking is per-file, not per-byte — subsequent `Edit` calls work anywhere in the file. Use this for partial updates against large canvas files (e.g., `purpose.yml` at 800+ lines). - **`Write`** (full replacement): do a **full Read** first. Write obliterates the file; you should see what you're about to replace. The `limit:1` shortcut is *not* appropriate here. …
Read the whole file at its exact version.
How to install
mdr add haabe/mycelium/ost-builder@sha256:c9de0a8e1d42a191The line at the top of this page pins the label git:20261106.598445d, 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_xgr4s6z2slkswrms)
7 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 24 versions of this file, between Jul 4, 2026 and Nov 6, 2026, about one every 5 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261106.598445d latest | 2026-11-06 | 598445d | 19,799 B | A | view · diff |
| git:20261011.ead7061 | 2026-10-11 | ead7061 | 19,106 B | A | view · diff |
| git:20261008.fc240ea | 2026-10-08 | fc240ea | 19,000 B | A | view · diff |
| git:20261007.33e0656 | 2026-10-07 | 33e0656 | 18,707 B | A | view · diff |
| git:20261005.c8a9906 | 2026-10-05 | c8a9906 | 18,670 B | A | view · diff |
| git:20261004.5ca76d9 | 2026-10-04 | 5ca76d9 | 18,343 B | A | view · diff |
| git:20261002.904f5d8 | 2026-10-02 | 904f5d8 | 17,962 B | A | view · diff |
| git:20261001.6e0641b | 2026-10-01 | 6e0641b | 17,961 B | A | view · diff |
| git:20260930.ab55808 | 2026-09-30 | ab55808 | 17,921 B | A | view · diff |
| git:20260924.1d8dc32 | 2026-09-24 | 1d8dc32 | 17,304 B | A | view · diff |
| git:20260924.81540c9 | 2026-09-24 | 81540c9 | 17,120 B | A | view · diff |
| git:20260923.2f23ecf | 2026-09-23 | 2f23ecf | 16,812 B | A | view · diff |
| git:20260923.0a9bc1d | 2026-09-23 | 0a9bc1d | 16,757 B | A | view · diff |
| git:20260922.f73af47 | 2026-09-22 | f73af47 | 16,509 B | A | view · diff |
| git:20260915.d7867a5 | 2026-09-15 | d7867a5 | 16,215 B | A | view · diff |
| git:20260915.6d95f44 | 2026-09-15 | 6d95f44 | 15,503 B | A | view · diff |
| git:20260915.d0d5b83 | 2026-09-15 | d0d5b83 | 14,894 B | A | view · diff |
| git:20260915.ae6b011 | 2026-09-15 | ae6b011 | 14,354 B | A | view · diff |
| git:20260914.4925bdb | 2026-09-14 | 4925bdb | 13,945 B | A | view · diff |
| git:20260822.2c9fea0 | 2026-08-22 | 2c9fea0 | 13,667 B | A | view · diff |
| git:20260813.418137c | 2026-08-13 | 418137c | 12,652 B | A | view · diff |
| git:20260805.d65286e | 2026-08-05 | d65286e | 12,023 B | A | view · diff |
| git:20260730.d47f9e6 | 2026-07-30 | d47f9e6 | 10,980 B | A | view · diff |
| git:20260704.7639f18 | 2026-07-04 | 7639f18 | 10,631 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 (19799 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
haabe/mycelium · 51 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_xgr4s6z2slkswrms GET https://markdownregistry.com/api/v1/resolve?ref=haabe/mycelium/ost-builder GET https://markdownregistry.com/api/v1/blob/c9de0a8e1d42a191341e9f7b3339480557f0fa25fb83328f3056892438b4283d
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.