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

# Track and version objects

> Track and version any JSON-serializable object in W&B Weave

## Objects

An **Object** is versioned, serializable data. Weave automatically versions objects when they change and creates an immutable history. Objects include:

* **Datasets**: Collections of examples for evaluation
* **Models**: Configurations and parameters for your LLM logic
* **Prompts**: Versioned prompt templates

```python lines theme={null}
dataset = weave.Dataset(
    name="test-cases",
    rows=[
        {"input": "What is 2+2?", "expected": "4"},
        {"input": "What is the capital of France?", "expected": "Paris"},
    ]
)
weave.publish(dataset)
```

## Publishing an object

Weave's serialization layer saves and versions objects.

<Tabs>
  <Tab title="Python">
    ```python lines theme={null}
    import weave
    weave.init("your-team-name/your-project-name")
    # Save a list, giving it the name 'cat-names'
    weave.publish(['felix', 'jimbo', 'billie'], 'cat-names')
    ```
  </Tab>

  <Tab title="TypeScript">
    Publishing in TypeScript is still early, so not all objects are fully supported yet.

    ```typescript lines theme={null}
    import * as weave from 'weave'

    const client = await weave.init("your-team-name/your-project-name")

    // Save an array, giving it the name 'cat-names'
    client.publish(['felix', 'jimbo', 'billie'], 'cat-names')
    ```
  </Tab>
</Tabs>

When you save an object with a name, Weave creates the first version of that object if it does not exist.

## Get an object back

<Tabs>
  <Tab title="Python">
    `weave.publish()` returns a Ref. You can call `.get()` on any Ref to get the object back.

    You can construct a ref and then fetch the object back.

    ```python lines theme={null}
    weave.init("your-team-name/your-project-name")
    cat_names = weave.ref('cat-names').get()
    ```
  </Tab>

  <Tab title="TypeScript">
    ```plaintext lines theme={null}
    This feature is not available in TypeScript yet.
    ```
  </Tab>
</Tabs>

## Delete an object

<Tabs>
  <Tab title="Python">
    To delete a version of an object, call `.delete()` on the object ref.

    ```python lines theme={null}
    weave.init("your-team-name/your-project-name")
    cat_names_ref = weave.ref('cat-names:v1')
    cat_names_ref.delete()
    ```

    Accessing a deleted object returns an error. Resolving an object that has a reference to a deleted object returns a `DeletedRef` in place of the deleted object.
  </Tab>

  <Tab title="TypeScript">
    ```plaintext theme={null}
    This feature is not available in TypeScript yet.
    ```
  </Tab>
</Tabs>

## Constructing object refs

In Weave, a fully qualified object ref URI looks like this:

```text theme={null}
weave:///<your-team-name>/<your-project-name>/object/<object_name>:<object_version>
```

* *your-team-name*: W\&B entity (username or team name)
* *your-project-name*: W\&B project
* *object\_name*: object name
* *object\_version*: either a version hash, a string like `v0` or `v1`, or an alias like `:latest`. All objects have the `:latest` alias.

You can construct refs with a few different styles:

* `weave.ref(<name>)`: Retrieves the `:latest` version of an object. Requires calling `weave.init(...)`.
* `weave.ref(<name>:<version>)`:  Retrieves the specified version of an object. Requires calling `weave.init(...)`.
* `weave.ref(<fully_qualified_ref_uri>)`: Retrieves the object located at the specified fully qualified object ref URI.  Does not require calling `weave.init()`.