# Capability / feature vocabulary (coulomb-social)

Status: **adopted for product work** (2026-08-12)  
Promote to fleet canon after one full cutover cycle.  
Cites: orthogonal architecture Capability (C1–C3, `realizes`); reuse-surface
for *cross-product* reuse only — not product feature flags.

## The coin

| Side | Name | Question |
|------|------|----------|
| **Utility** | **Capability** | What can a person *do* or *get*? Stable job-to-be-done. |
| **Implementation** | **Feature** | Which concrete product slice delivers (part of) that utility? |

Capabilities change slowly. Features appear, split, toggle, and retire under them.

## Hierarchy (depth capped)

```text
Capability
  └── Feature+          (implementation slices)
        └── Realization (code, config, deploy)   — optional detail
        └── Toggle?     (runtime/config switch on a feature or stage)
```

Rules:

1. **Capabilities: few.** Target ~10–30 for all of coulomb.social, not hundreds.
2. **No unlimited trees.** At most capability → optional sub-capability → feature.
3. **One feature, one primary capability.** Cross-links allowed as `supports`, not multi-parent ownership.
4. **Toggles attach to features (or release stages), never to capabilities.**  
   “Turn off identity” is a product decision, not a flag.
5. **Feature cut = prioritize capabilities**, then name which features are enough to call a capability *realized for that stage*.
6. **Partial rebuild is valid.** Stage N can retire Bubble as *productive* home while Bubble remains *reference-only* for later capabilities.

## Status labels

### Capability priority (cut / roadmap)

| Label | Meaning |
|-------|---------|
| `must_stage_1` | Required before user transfer + Bubble productive retirement |
| `later` | Rebuild after stage 1; not a transfer blocker |
| `out` | Explicitly not rebuilding (or only if strategy changes) |
| `platform` | Delivered by platform dependency (NetKingdom, Forgejo, …) |

### Feature implementation status

| Label | Meaning |
|-------|---------|
| `shipped` | On app.coulomb.social (or ready to enable) |
| `partial` | Exists but missing stage-1 acceptance bits |
| `todo` | Not built; required for its capability stage |
| `later` | Intentionally after stage 1 |
| `blocked` | Waiting on external dependency |

## What not to conflate

| Concept | Home |
|---------|------|
| Product capability (user utility) | This model |
| Fleet reusable capability | reuse-surface registry |
| Platform service (OIDC, Forgejo, apps-pg) | Platform deps; product *depends_on* |
| Feature toggle | Env/settings/flag on a **feature** |
| Workplan task | Execution unit; may implement many features |

## Naming

- Capabilities: `cap.<kebab>` — noun phrase of utility  
  e.g. `cap.space-content`
- Features: `feat.<kebab>` — verb/noun of implementation  
  e.g. `feat.space-md-render`
- Prefer stable ids; titles may change.