AI-Native Formal Specification Language — a bounded model checker (Lark + Z3) built for LLM write/verify/repair loops.
This repository also configures its own agents. See what fsl tells them →
Skill Codex
Write and verify FSL business-layer specs for consultants, business owners, and PMs explicitly working on business-flow policy. Use for As-Is/To-Be process flows, actors, case stages, business policies, controls, KPIs, goals, and reform/control-preservation checks. Do not use for system requirements, UI/API/data-model…
Skill Codex
Orchestrate an FSL-centered delivery workflow from business planning through PM requirements, engineering design, verification, refinement, scenarios, testgen/replay, and implementation conformance. Use when the user asks to drive a feature/project "from planning to implementation" with FSL as the backbone, connect…
Skill Claude CodeCodex
A procedure for design exploration and design review using FSL. Mechanically check with fslc refine whether a design proposal, variant, extension, or change breaks a stable contract (the abstract spec), and report the result in the vocabulary of design principles (SOLID — the Open/Closed Principle, the Liskov…
Skill Codex
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, typestate checks, scenarios-to-testgen handoff, and implementation-conformance planning. Do not use for PM…
Skill Claude CodeCodex
Reverse-engineer an FSL design-layer spec from existing source code. Scope the stateful subsystem, harvest state/actions/guards/effects with source-line witnesses, surface invariants and forbidden flows as confirmation questions (never fabricated), then verify, mutation-test for hollowness, and prove conformance by…
Skill Claude CodeCodex
Generate, edit, and re-verify a human-readable requirements document (Markdown) from a checked FSL requirements/spec dialect file, using fslc document generate/claims/check. The agent is a non-normative editor and review-support assistant, never a compiler — it may only fill in the document's editable slot…
Skill Codex
Write and verify FSL requirements-layer specs for PMs/PdMs from natural-language product requirements, acceptance criteria, forbidden flows, requirement IDs, traceability, and NFRs such as permissions, audit, capacity, reliability, and SLA/deadline behavior. Use when the deliverable is a requirements specification…
Skill Claude CodeCodex
Shared FSL language and verifier reference for writing, checking, verifying, repairing, explaining, mutating, refining, replaying, generating scenarios/test scaffolds, and interpreting fslc JSON results. Use directly for FSL syntax, kernel specs, verifier errors, repair loops, and command usage. For role-specific…
Skill Codex
Run, read, and report fslc verification for an FSL spec at any layer (business, requirements, design, or the whole chain). Use when asked to verify, check, prove, or gate a spec ("verify this spec", "is it proved", "is it ready to hand over", "can development start from this", "how strong is the spec", "did this…
At most 3 mods per repository are shown here, and a mod shipped inside a plugin is left to that plugin's page — the rest are on their repository pages: