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

# Proof links and versioning

> Optional patterns for linking portable proofs with typed references and supersedes tags.

Use these patterns when an integration needs linked proofs, version history, or tag-based lookup.

**Proof ID** in API responses is `qHash`.

## Typed reference: `reference.type: "qhash"`

The `ownership-basic` check accepts a `reference` object with `type: "qhash"` and `id` set to another proof's ID. That creates a typed link from one proof to another.

```json theme={"dark"}
{
  "verifierIds": ["ownership-basic"],
  "data": {
    "owner": "0x...",
    "reference": {
      "type": "qhash",
      "id": "0xe1a2b3c4d5e6f7081920212232425262728292a2b2c2d2e2f303132333435363",
      "title": "Agent identity proof"
    }
  }
}
```

Reference payloads for the same target commonly hash from `qhash:{targetId}` in the signed content. Confirm current behavior in the [ownership-basic](../verification/ownership-basic) capability reference and live API responses. Do not invent proof IDs.

## Version chain: `supersedes:<qHash>` tag

When you update a memory or instruction proof, NEUS can tag the new proof with `supersedes:<previousQHash>`. Newer proofs point back to older ones.

```text theme={"dark"}
Proof A → supersedes:none
Proof B → supersedes:0xA  (replaces A)
Proof C → supersedes:0xB  (replaces B)
```

Use `neus_proofs_get` to walk the chain and read history.

## Tag prefixes for discovery

Tag prefixes help you filter related proofs. Common prefixes include subject facets (`topic:`, `domain:`) and review state (`quality:draft` / `quality:approved`). Query tagged proofs with [`neus_proofs_get`](../mcp/proofs-get). To attach an agent profile to a project, see [Connect agent context](../agents/runtime-mount).

## Large content

Inline proof content has a size limit (about 50,000 characters). For larger artifacts, store the canonical file elsewhere and attach a short proof that references it (`reference` URL or content hash), or split content across multiple proofs only when your integration explicitly supports that pattern.

## Next

<CardGroup cols={2}>
  <Card title="Proofs" icon="shield-check" href="../platform/proofs">
    How proofs work on NEUS.
  </Card>

  <Card title="Guard an agent action" icon="refresh-cw" href="../mcp/guarded-action">
    Check permissions before a tool runs.
  </Card>

  <Card title="Proofs read" icon="search" href="../mcp/proofs-get">
    Query proofs by tag and scope.
  </Card>

  <Card title="ownership-basic" icon="file" href="../verification/ownership-basic">
    Check inputs for content and references.
  </Card>
</CardGroup>