> ## Documentation Index
> Fetch the complete documentation index at: https://docs.quanux.org/symphony/llms.txt
> Use this file to discover all available pages before exploring further.

# SSFV: Symphony Semantic Feature Vector and Registry

> SSFV owns canonical feature identity, semantics, hierarchy, lifecycle, and administration assurance across every implemented Symphony module and qxctl surface.

The Symphony Semantic Feature Vector (SSFV) owns canonical application-feature identity, semantics, hierarchy, lifecycle, distinctions, distributed record routing, coverage inventory, and graph-projection contracts. Its engine is an independently installable C++ process that performs structural and freshness-aware feature checks.

## Operations

* **Inspect and check**: structural and freshness-aware feature evaluation.
* **Diff**: content-addressed diffs between feature states.
* **Propose**: caller-declared proposals for feature admission or change.
* **Graph**: deterministic disposable feature graphs for review.

## Registered coverage

The current registered catalog is explicitly partial:

* **110** registered features
* **35** registered owner scopes
* **76** ratified nested features
* **295** reviewed feature-administration surfaces (**285** required, **13** evidence-backed exemptions, **9** prohibitions, **0** unreviewed)

Registered owner scopes span every implemented module, from `qxctl` and the validator through SKV engines and SSIAG providers to the SCV and SHV engine families.

## What SSFV does not do

<Warning>
  SSFV does not decide feature-worthiness, invent identities, or claim repository or host completeness. `review_required` is evidence for caller review, not ratification or apply authority.
</Warning>

Feature review, admission, and lifecycle changes stay with each feature's owning contract.

## Related surfaces

<CardGroup cols={2}>
  <Card title="SKV overview" icon="book-open" href="/symphony/symphony/skv/overview">
    The umbrella framework that governs SSFV.
  </Card>

  <Card title="SEV" icon="arrow-trend-up" href="/symphony/symphony/skv/sev">
    Applies evolution cases to feature additions, changes, and retirements.
  </Card>

  <Card title="qxctl session" icon="terminal" href="/symphony/symphony/qxctl/session">
    Manage persistent SSFV maintenance sessions via qxctl.
  </Card>

  <Card title="qxctl vector commands" icon="terminal" href="/symphony/symphony/qxctl/vector-commands">
    Run `qxctl ssfv ...` for inspect, check, diff, propose, and graph.
  </Card>
</CardGroup>


## Related topics

- [SEV: Symphony Evolution Vector for Planned Changes](/symphony/symphony/skv/sev.md)
- [qxctl: Symphony Agentic Administrative Command Line](/symphony/symphony/qxctl/overview.md)
- [Symphony Validator: Deterministic Read-Only Repository Checks](/symphony/symphony/governance/validator.md)
- [qxctl knowledge session: Authenticated Symphony Sessions](/symphony/symphony/qxctl/session.md)
- [qxctl Vector Commands: skvi, sclv, sacv, sodv, ssfv, shv](/symphony/symphony/qxctl/vector-commands.md)