| name | lamina-product-behavior |
| description | Represented model matches domain — UI must not imply illegal states or permissions. Use when run.json domain and screens diverge from implementation shape. |
| metadata | {"lamina":{"id":"product-behavior","problems":["UI mirrors database or org structure","represented vs mental model","behavior before build"],"related":["lamina-flow-design","lamina-user-modeling","lamina-platform-posture","lamina-invariants"]}} |
Product Behavior (agent-native)
The represented model in run.json must match how actors conceive tasks — simpler than implementation, aligned with domain invariants.
Contract encoding
| Layer | Artifact |
|---|
| Domain truth | entities[], invariants[] |
| What actors can do | actors.permissions, workflows |
| What UI shows | surfaces[] — no affordance for forbidden operations |
| Illegal states | scenarios[] + disabled/hidden actions in screen spec |
Implementation model stays in external code. Lamina specifies represented model only.
Frameworks
- Goals vs tasks: Design for stable goals; eliminate tasks technology made obsolete.
- Capability / viability / desirability: Record trade-offs in
decisions.md when pillars conflict.
- Design values: e.g. don't make actors feel stupid — use as filter when reconciling persona panel conflicts.
- Patterns: Modeless feedback, reversible actions — reference in
implement.md, don't prescribe UI library.
Design checklists
- No screen shows actions the actor cannot perform (or shows why disabled).
- Entity names in UI match
entities[] vocabulary.
- States visible to actors match the entity lifecycles — no mystery modes.
- Primary actor path optimized; edge cases in scenarios, not driving IA.
- Deviations from common patterns documented in
decisions.md.
Verify checks
- Actor walks: forbidden operations blocked with scenario-matching
ux.
- Invariant probes: UI never implies illegal state (e.g. two active tickets).
- Walkthrough: represented labels match contract entity names.
Anti-patterns
- Elastic user: Generic actor justifying any design choice.
- UI after coding: Contract written to match accidental implementation.
- Implementation-shaped menus: File/Edit mirroring backend modules.
- Feature lists without goals: Workflows not traceable to actor outcomes.
Related
