# Links

Links let you add clickable URLs to tasks that appear in the Flyte UI. Use them to connect tasks to external tools like experiment trackers, monitoring dashboards or custom internal services.

![Links in the Flyte UI](https://raw.githubusercontent.com/unionai/unionai-docs-static/refs/heads/main/images/integrations/wandb/single_node_auto_flyte.png)

You can attach links to tasks in two ways:

- **Statically** in the task decorator with `links=`
- **Dynamically** at call time with `task.override(links=...)`

`Link` is a Python [Protocol](https://docs.python.org/3/library/typing.html#typing.Protocol) that you subclass to define how URLs are generated. The Weights & Biases plugin provides a [built-in link implementation](https://www.union.ai/docs/v2/union/user-guide/api-reference/integrations/wandb/packages/flyteplugins.wandb/wandb) as an example.

## Creating a link

To create a link, subclass `Link` as a dataclass and implement the `get_link()` method. The method returns the URL string to display in the UI:

```python
from dataclasses import dataclass

import flyte
from flyte import Link

@dataclass
class GrafanaLink(Link):
    dashboard_url: str
    name: str = "Grafana"

    def get_link(
        self,
        run_name: str,
        project: str,
        domain: str,
        context: dict,
        parent_action_name: str,
        action_name: str,
        pod_name: str,
        **kwargs,
    ) -> str:
        return f"{self.dashboard_url}?var-pod={pod_name}"

env = flyte.TaskEnvironment(...)

@env.task(links=(GrafanaLink(dashboard_url="https://grafana.example.com/d/abc123"),))
def my_task() -> str:
    return "done"
```

The link appears as a clickable "Grafana" link in the Flyte UI for every execution of `my_task`.

## Using execution metadata

The `get_link()` method receives execution metadata that you can use to construct dynamic URLs. Here's an example modeled on the [built-in Wandb](https://www.union.ai/docs/v2/union/user-guide/integrations/wandb/_index) link that uses the `context` dict to resolve a run ID:

```python
from dataclasses import dataclass
from typing import Optional

from flyte import Link

@dataclass
class Wandb(Link):
    project: str
    entity: str
    id: Optional[str] = None
    name: str = "Weights & Biases"

    def get_link(
        self,
        run_name: str,
        project: str,
        domain: str,
        context: dict[str, str],
        parent_action_name: str,
        action_name: str,
        pod_name: str,
        **kwargs,
    ) -> str:
        run_id = self.id or context.get("wandb_id", run_name)
        return f"https://wandb.ai/{self.entity}/{self.project}/runs/{run_id}"
```

The `name` attribute controls the display label in the UI.

See the [`get_link()` API reference](https://www.union.ai/docs/v2/union/user-guide/api-reference/flyte-sdk/packages/flyte/link#get_link) for more details. Note that `action_name` and `pod_name` are template variables (`{{.actionName}}` and `{{.podName}}`) that are populated by the backend at runtime.

## Dynamic links with override

Use `task.override(links=...)` to set links at runtime. This is useful when link parameters depend on runtime values like run IDs or configuration:

```python
import os

import flyte
from flyteplugins.wandb import Wandb

env = flyte.TaskEnvironment(...)

WANDB_PROJECT = "my-ml-project"
WANDB_ENTITY = "my-team"

@env.task
def train_model(config: dict) -> dict:
    # Training logic here
    return {"accuracy": 0.95}

@env.task
async def main(wandb_id: str) -> dict:
    result = train_model.override(
        links=(
            Wandb(
                project=WANDB_PROJECT,
                entity=WANDB_ENTITY,
                id=wandb_id,
            ),
        )
    )(config={"lr": 0.001})

    return result

if __name__ == "__main__":
    flyte.init_from_config()
    run = flyte.run(main, wandb_id="my-run-id")
```

The `override` approach lets you attach links with values that are only known at runtime, such as dynamically generated run IDs.

---
**Source**: https://github.com/unionai/unionai-docs/blob/main/content/user-guide/task-programming/links.md
**HTML**: https://www.union.ai/docs/v2/union/user-guide/task-programming/links/