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

# Sense content authentication

> Submit a file for AI powered near-duplicate analysis and record the result permanently on chain.

Sense is Lumera Protocol's AI powered content authentication service. Submit a file and top ranked SuperNodes analyze it with perceptual fingerprinting. A perceptual fingerprint is a feature vector that captures what the content looks like rather than its exact bytes. The network compares it against every previously registered asset and records a verifiable similarity result on chain through the `x/action` module. Slightly altered copies still match, which plain hash comparison cannot do.

This page covers what Sense is for, how an analysis runs, and how to submit and query Sense actions with `lumerad`.

## Use cases

<CardGroup cols={2}>
  <Card title="NFT uniqueness verification" icon="image">
    Prove that a digital artwork is not a near duplicate of a registered asset before minting.
  </Card>

  <Card title="Content originality checks" icon="magnifying-glass">
    Verify the originality of visual or audio content before publishing or licensing it.
  </Card>

  <Card title="Digital asset provenance" icon="link">
    Establish a timestamped on-chain record that a file existed in a unique form at a specific block height.
  </Card>

  <Card title="Duplicate prevention" icon="shield">
    Keep near duplicates from flooding marketplaces and diluting the value of originals.
  </Card>
</CardGroup>

## How Sense works

<Steps>
  <Step title="Register the action on chain">
    You submit a registration transaction carrying the hash of your file. The `x/action` module escrows the fee and assigns a unique `action_id`. The action starts in the `PENDING` state.
  </Step>

  <Step title="SuperNodes run fingerprint analysis">
    Top ranked SuperNodes, selected through `x/supernode`, pick up the action and process the file. Each one computes a perceptual fingerprint of the content. The state is `PROCESSING`.
  </Step>

  <Step title="Results are aggregated">
    The SuperNodes compare the fingerprint against the network's registered assets. They compute a similarity score and collect any duplicate candidates that exceed the near-duplicate threshold.
  </Step>

  <Step title="The result is recorded on chain">
    The aggregated result is committed and the action moves to `DONE`. The similarity score, duplicate candidates, and fingerprint hash become part of the permanent record, queryable by anyone.
  </Step>
</Steps>

A failed action becomes `FAILED` and the escrowed fee is refunded. The [architecture page](/architecture) walks the full action state machine that Sense shares with Cascade.

## Submitting a Sense action

Register a Sense action with the `request-action` command. It takes four positional arguments, the action type, a metadata JSON string, the service price you offer, and an expiration timestamp.

<Tabs>
  <Tab title="Mainnet">
    ```shell Register a Sense action theme={null}
    lumerad tx action request-action SENSE '<metadata-json>' <price> <expiration-time> \
      --from <key-name> \
      --chain-id lumera-mainnet-1 \
      --fees 10000ulume
    ```
  </Tab>

  <Tab title="Testnet">
    ```shell Register a Sense action theme={null}
    lumerad tx action request-action SENSE '<metadata-json>' <price> <expiration-time> \
      --from <key-name> \
      --chain-id lumera-testnet-2 \
      --fees 10000ulume
    ```
  </Tab>
</Tabs>

The metadata JSON carries the hash of the file you want analyzed in its `data_hash` field. The price is denominated in `ulume` and the expiration time is a Unix timestamp for when the action expires. After broadcasting, note the `action_id` returned in the transaction response.

## Querying Sense results

Once the action reaches `DONE`, the result lives in the on-chain action record.

```shell Query a Sense action theme={null}
lumerad query action action <action-id>
```

The response includes the action metadata, the current state, and the encoded Sense result payload. For a decoded, human readable view over REST, use the [LumeScope API](/api/lumescope).

## Result fields

| Field                | Meaning                                                                                                |
| -------------------- | ------------------------------------------------------------------------------------------------------ |
| Similarity score     | A value between 0 and 1. Near 0 means highly unique, near 1 means a close match to a registered asset. |
| Duplicate candidates | Action IDs of previously registered files that exceeded the near-duplicate threshold.                  |
| Fingerprint hash     | Hash of the perceptual fingerprint vector, usable to verify the result independently.                  |
| Block height         | The block where the result was recorded, a tamper-proof timestamp.                                     |

<Note>
  Sense results are permanent. Anyone can query the record, check the similarity score, and audit the duplicate candidates, which gives your assets a transparent provenance trail.
</Note>

## Pricing

A Sense action pays two fees.

* A standard transaction fee in `ulume` for the registration message.
* A service fee escrowed by `x/action` and paid to the SuperNodes that run the analysis.

Sense costs less than Cascade because only the analysis result is stored, never the file itself. Governance can change fee parameters at any time.

## Next steps

<CardGroup cols={2}>
  <Card title="Module reference" icon="cubes" href="/protocol/modules">
    How x/action and x/supernode coordinate Sense under the hood.
  </Card>

  <Card title="LumeScope API" icon="code" href="/api/lumescope">
    Decoded action results and network state over REST.
  </Card>

  <Card title="How Cascade works" icon="database" href="/cascade/how-cascade-works">
    Permanent file storage, the sibling service to Sense.
  </Card>
</CardGroup>