fsl-from-code SKILL.md skillA
fsl-from-code from ymm-oss/fsl is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add ymm-oss/fsl/fsl-from-code@git:20261107.deab533Pins git:20261107.deab533 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- ymm-oss/fsl
- Path
skills/fsl-from-code/SKILL.md- Versions recorded
- 6
- Latest version
- git:20261107.deab533, committed Nov 7, 2026
- First version recorded
- Jun 25, 2026
- Size
- 8,084 bytes
- Repository stars
- 37
- License
- Apache-2.0
Reverse-engineer a witnessed FSL design-layer kernel spec from existing code, using the fsl 5 kernel form. Harvest state/actions/guards/effects, confirm cross-action invariants and negative intent with a human, verify and mutation-test, then wire and execute the real-code conformance harness. Use when code is input and a design spec is the deliverable, not requirements/business discovery or design from an upper contract.
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
# FSL From Code — implementation → witnessed design model
A headerless document is FSL 4; to migrate it, see the migration guide in `docs/manual/LANGUAGE.md` ("FSL 4 to FSL 5 migration").
The seam points downward: code → source-witnessed kernel spec → real-code
conformance tests. There is no inferred upper requirements contract. If one is
later agreed, building the upward refinement seam belongs to
[design](../fsl-design/SKILL.md), not automatic reverse-engineering.
Before syntax read [core](../fsl/SKILL.md), its relevant references and
[verify](../fsl-verify/SKILL.md). Produce:
- A kernel `spec` headed `fsl 5`, with `// SRC: file:line` witnesses for
state/actions/guards/effects and any source-grounded invariants.
- Human-confirmed cross-action safety/history/progress intent, carried in
`// ASSUME-n:` comments and typed requirement/model/assumption tags.
- A testgen Adapter wired to real code, plus executed random-walk/replay evidence.
Do not invent states/guards/invariants to reach green, create a business or
requirements layer, or claim conformance from model verification alone. A kernel
spec cannot acquire requirements-only scenario/forbidden blocks. Express confirmed
…Read the whole file at its exact version.
How to install
mdr add ymm-oss/fsl/fsl-from-code@sha256:48fa8ce8bd60dec4The line at the top of this page pins the label git:20261107.deab533, 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_hv6vt4j737yhcjny)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 6 versions of this file, between Jun 25, 2026 and Nov 7, 2026, about one every 27 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261107.deab533 latest | 2026-11-07 | deab533 | 8,084 B | A | view · diff |
| git:20261017.bf06ebf | 2026-10-17 | bf06ebf | 10,037 B | A | view · diff |
| git:20260828.927728f | 2026-08-28 | 927728f | 9,970 B | A | view · diff |
| git:20260706.7fb3417 | 2026-07-06 | 7fb3417 | 9,951 B | A | view · diff |
| git:20260626.58f2f6b | 2026-06-26 | 58f2f6b | 9,693 B | A | view · diff |
| git:20260625.46b8074 | 2026-06-25 | 46b8074 | 9,492 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 (8084 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
ymm-oss/fsl · 37 stars · license Apache-2.0 · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_hv6vt4j737yhcjny GET https://markdownregistry.com/api/v1/resolve?ref=ymm-oss/fsl/fsl-from-code GET https://markdownregistry.com/api/v1/blob/48fa8ce8bd60dec40745f75ddff36392657a25fba3d38f14052ff311cff7dfcd
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.