> ## 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.

# Symphony Validator: Deterministic Read-Only Repository Checks

> The Symphony Validator produces line or structured JSON evidence for contracts, source closure, invariants, features, releases, and the machine-checked root summary.

The Symphony Validator (`tools/symphony-validator`) is an independent, deterministic, read-only C++26 repository checker. It produces immutable evidence about the current state of the repository and its contracts. It cannot repair or publish anything.

## What the validator checks

* Contract shape: required Contract Quad anchors and structure
* Current source closure across SKVI-indexed surfaces
* Invariant ownership per `knowledge/INVARIANTS.md` and the invariant registry
* Feature administration expectations reported by SSFV
* Release records reported by SODV
* The machine-owned root summary in the repository README

Evidence is emitted as line output or structured JSON. Every emission is reproducible from the same repository state.

## What the validator does not do

<Warning>
  The validator cannot repair files, rewrite contracts, or publish the repository. It creates canonical truth about nothing; it only reports it.
</Warning>

* No side effects on the repository
* No network access
* No warning suppression outside of qxctl's protected warning policy

## qxctl integration

qxctl validates the validator's exact receipt and structured digests before applying protected warning policy. Nine protected warning-lifecycle qxctl leaves plus the exact receipt-backed root-summary route expose validation administration without altering raw detector evidence.

## Related surfaces

<CardGroup cols={2}>
  <Card title="qxctl validate" icon="terminal" href="/symphony/symphony/qxctl/validate">
    Protected warning policy, baseline, and display grammar.
  </Card>

  <Card title="SSFV" icon="list-check" href="/symphony/symphony/skv/ssfv">
    Feature administration expectations checked by the validator.
  </Card>

  <Card title="SODV" icon="scroll" href="/symphony/symphony/skv/sodv">
    Release records the validator inspects.
  </Card>

  <Card title="SKV overview" icon="book-open" href="/symphony/symphony/skv/overview">
    The umbrella framework whose contracts the validator checks.
  </Card>
</CardGroup>


## Related topics

- [qxctl validate: Symphony Validator Warning Policy](/symphony/symphony/qxctl/validate.md)
- [SKVI: The Symphony Knowledge Vector Index Engine](/symphony/symphony/skv/skvi.md)
- [SCLV: Symphony Change Ledger Vector for Source Changes](/symphony/symphony/skv/sclv.md)
- [Knowledge Session Coordinator for Symphony Vector Engines](/symphony/symphony/engines/coordinator.md)
- [Knowledge Vector Engine C++ Foundation: Shared Mechanics](/symphony/symphony/engines/knowledge-vector-foundation.md)