fsl-design SKILL.md skillA
fsl-design 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-design@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-design/SKILL.md- Versions recorded
- 9
- Latest version
- git:20261107.deab533, committed Nov 7, 2026
- First version recorded
- Jun 20, 2026
- Size
- 12,650 bytes
- Repository stars
- 37
- License
- Apache-2.0
Write and verify FSL design-layer specs for engineers from an agreed requirements contract. Use for internal state/action design, decomposition, queues/outboxes, compose, refinement mappings to requirements (including requirements written with entities, events, rules, decision tables and a glossary), typestate checks, scenarios-to-testgen handoff, and implementation-conformance planning. Do not use for PM requirements authoring or business process discovery.
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 Design Layer
A headerless document is FSL 4; to migrate it, see the migration guide in `docs/manual/LANGUAGE.md` ("FSL 4 to FSL 5 migration").
Use this skill after a requirements contract exists or the user explicitly asks
for engineering design. The design layer is an ordinary kernel `spec` headed
`fsl 5`, plus a refinement mapping back to the requirements layer. That mapping
is the **refinement seam, not a plain baton pass**: the design must refine the
(frozen) requirements contract, and `fslc refine` verifies the seam. When a
seam breaks, repair the design or the mapping — not the upper contract, unless
a human revises it.
Kernel syntax (state, init, actions, properties, `struct`, `Map`, `Seq`,
`compose`) is in `../fsl/references/syntax.md`; the refinement file and the
seam rules are in `../fsl/references/syntax.md` and
`../fsl/references/layers.md`. Use `fsl-design-review` instead when the user
asks for a design review, SOLID judgment, substitutability, or variant
comparison.
## What the `fsl 5` header changes here
- The kernel language is the same. The stricter rules of the edition are
errors: `check` answers `result: "error"`, `kind: "unsupported_in_edition"`
…Read the whole file at its exact version.
How to install
mdr add ymm-oss/fsl/fsl-design@sha256:c078aa326b80cdf2The 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_xvjg7ippmaoaly32)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 9 versions of this file, between Jun 20, 2026 and Nov 7, 2026, about one every 17 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261107.deab533 latest | 2026-11-07 | deab533 | 12,650 B | A | view · diff |
| git:20261017.bf06ebf | 2026-10-17 | bf06ebf | 10,200 B | A | view · diff |
| git:20261015.5401e68 | 2026-10-15 | 5401e68 | 9,392 B | A | view · diff |
| git:20260929.d8a8acc | 2026-09-29 | d8a8acc | 5,251 B | A | view · diff |
| git:20260828.927728f | 2026-08-28 | 927728f | 5,244 B | A | view · diff |
| git:20260727.4af5738 | 2026-07-27 | 4af5738 | 5,235 B | A | view · diff |
| git:20260626.58f2f6b | 2026-06-26 | 58f2f6b | 4,443 B | A | view · diff |
| git:20260625.5bdeef9 | 2026-06-25 | 5bdeef9 | 4,174 B | A | view · diff |
| git:20260620.992ded1 | 2026-06-20 | 992ded1 | 3,763 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 (12650 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_xvjg7ippmaoaly32 GET https://markdownregistry.com/api/v1/resolve?ref=ymm-oss/fsl/fsl-design GET https://markdownregistry.com/api/v1/blob/c078aa326b80cdf27192e9a67c365272a302ed98f6ebd4af9a9c8688d04acd3b
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.