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

# Weights schema

> Field-level reference for the weight vector models used by the subnet master and challenges.

This page is the field-level reference for the weight models defined in
`schemas/weights.py`. For the public read that returns the aggregated vector, see
[Weights API](/reference/api-weights).

## `MasterWeightsResponse`

The aggregated, chain-ready weight vector returned by
`GET /v1/weights/latest` (`schemas/weights.py:33-42`).

| Field                  | Type                              | Default | Source                  |
| ---------------------- | --------------------------------- | ------- | ----------------------- |
| `netuid`               | integer                           | —       | `schemas/weights.py:34` |
| `chain_endpoint`       | string                            | —       | `schemas/weights.py:35` |
| `uids`                 | array of integer                  | —       | `schemas/weights.py:36` |
| `weights`              | array of number                   | —       | `schemas/weights.py:37` |
| `hotkey_weights`       | object (string → number)          | `{}`    | `schemas/weights.py:38` |
| `computed_at`          | datetime                          | —       | `schemas/weights.py:39` |
| `expires_at`           | datetime                          | —       | `schemas/weights.py:40` |
| `source_challenges`    | array of `ChallengeWeightsResult` | —       | `schemas/weights.py:41` |
| `metagraph_updated_at` | datetime                          | —       | `schemas/weights.py:42` |

`uids` and `weights` are parallel arrays — the weight at index `i` applies to the
UID at index `i`. `expires_at` is validated to be in the future when the model is
constructed; a non-future value raises a validation error
(`schemas/weights.py:44-48`).

## `ChallengeWeightsResult`

A single challenge's contribution inside `source_challenges`
(`schemas/weights.py:19-24`).

| Field              | Type                     | Default | Source                  |
| ------------------ | ------------------------ | ------- | ----------------------- |
| `slug`             | string                   | —       | `schemas/weights.py:20` |
| `emission_percent` | number                   | —       | `schemas/weights.py:21` |
| `weights`          | object (string → number) | `{}`    | `schemas/weights.py:22` |
| `ok`               | boolean                  | `true`  | `schemas/weights.py:23` |
| `error`            | string or null           | `null`  | `schemas/weights.py:24` |

When a challenge collection fails, `ok` is `false` and `error` carries the
failure detail while `weights` stays empty (`challenge_client.py:54-59`).

## `ChallengeWeightsResponse`

The shape a challenge returns from its internal `get_weights` endpoint, which the
master collects per challenge (`schemas/weights.py:11-16`,
`challenge_client.py:31`, `challenge_client.py:43`).

| Field            | Type                     | Default   | Source                  |
| ---------------- | ------------------------ | --------- | ----------------------- |
| `challenge_slug` | string                   | —         | `schemas/weights.py:12` |
| `epoch`          | integer or null          | `null`    | `schemas/weights.py:13` |
| `weights`        | object (string → number) | `{}`      | `schemas/weights.py:14` |
| `metadata`       | object                   | `{}`      | `schemas/weights.py:15` |
| `computed_at`    | datetime                 | now (UTC) | `schemas/weights.py:16` |

## `FinalWeights`

The internal vector model pairing UIDs with weights and per-hotkey weights
(`schemas/weights.py:27-30`).

| Field            | Type                     | Default | Source                  |
| ---------------- | ------------------------ | ------- | ----------------------- |
| `uids`           | array of integer         | —       | `schemas/weights.py:28` |
| `weights`        | array of number          | —       | `schemas/weights.py:29` |
| `hotkey_weights` | object (string → number) | `{}`    | `schemas/weights.py:30` |

## Freshness constant

`MASTER_WEIGHTS_FRESHNESS_SECONDS = 720` defines the freshness window for the
master weights (`schemas/weights.py:8`).

## Related

<CardGroup cols={2}>
  <Card title="Weights pipeline" icon="scale-balanced" href="/architecture/weights-pipeline">
    How these models are produced each epoch.
  </Card>

  <Card title="Weights API" icon="scale-balanced" href="/reference/api-weights">
    The public read that returns these models.
  </Card>
</CardGroup>