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+---
+name: fesa-requirements-baseline
+description: Use when defining FESA solver feature requirements, acceptance criteria, tolerance decisions, verification quantities, and a requirement verification matrix before research, formulation, reference modeling, or implementation planning.
+---
+
+# FESA Requirements Baseline
+
+Use this skill to turn a solver feature request into a verifiable baseline that downstream agents can use without guessing.
+
+## Inputs
+
+Read these first:
+
+- `AGENTS.md`
+- `docs/SOLVER_AGENT_DESIGN.md`
+- `docs/requirements/README.md`
+- User feature request, target capability, constraints, and known exclusions
+- Existing `docs/requirements/<feature-id>.md` when revising a feature
+
+## Workflow
+
+1. Assign a stable `feature_id` in kebab case.
+2. Define purpose, included scope, excluded scope, and analysis definition.
+3. Convert requested behavior into `shall` statements with ids like `FESA-REQ-<FEATURE>-###`.
+4. Define verification quantities: displacement, reaction, element force, stress, strain, energy, or residual.
+5. Record Tolerance Policy values or mark them `needs-user-decision`.
+6. Record Reference Artifact Requirements under `references/<feature-id>/`.
+7. Build a Requirement Verification Matrix that maps requirement, source, verification method, acceptance criteria, tolerance, downstream agents, and status.
+8. Keep unresolved decisions visible as open issues; do not hide gaps behind vague wording.
+
+## Output Contract
+
+Produce or revise `docs/requirements/<feature-id>.md` with:
+
+- Metadata with `feature_id`, status, owner agent, and date
+- Purpose, In Scope, Out Of Scope, and Analysis Definition
+- Input and Output Requirements
+- Verification Quantities
+- Tolerance Policy
+- Reference Artifact Requirements
+- Requirement Verification Matrix
+- Open Questions and Downstream Handoff
+
+## Boundaries
+
+- Do not implement C++ code.
+- Do not write finite element formulations.
+- Do not design C++ APIs or file ownership.
+- Do not run Abaqus, Nastran, or any reference solver.
+- Do not generate reference CSVs.
+- Do not approve release readiness.
+
+## Quality Gate
+
+- Every `must` requirement has a verification method and acceptance criteria.
+- Every numerical requirement has units, coordinate system, and tolerance or an explicit owner for the decision.
+- Every reference-comparison requirement names required artifacts.
+- Words like "accurate", "fast", and "Abaqus-like" are converted into measurable criteria or open questions.
+
+## Handoff
+
+Route theory gaps to Research Agent, math gaps to Formulation Agent, schema gaps to I/O Definition Agent, reference artifact needs to Reference Model Agent, and implementation readiness to Implementation Planning Agent.