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

# What Is a Feed

> Learn the core primitive behind Atria workflows.

# What Is a Feed

A feed is Atria's core primitive for building event-driven workflows. It listens to a specific type of blockchain data, decides what matters, and emits a structured payload when the feed logic matches.

## Anatomy

* **Source**: Network, data type, and optional block range.
* **Filter**: Feed logic that decides whether to emit and can shape the payload it returns. In the current runtime, filters are authored in JavaScript.
* **Function**: Optional post-filter logic for heavier enrichment, integration-specific formatting, or complex transformation.
* **Outputs**: Connectors that use the emitted payload to trigger the next action.
* **Cursor**: Stored progress that tells the runtime which block to process next.
* **Metadata**: Name, version, tags, description, status, and deployment history.

```mermaid theme={null}
flowchart LR
  Source[Source] --> Filter[Filter]
  Filter --> Function[Optional function]
  Function --> Outputs[Outputs]
```

## Feed Input

Feed input comes from one [data type](/atria/core-concepts/data-types), such as `BlockWithTransactions` or `BlockWithLogs`.

## Feed Output

If the feed returns `null` or `undefined`, Atria emits no result. If it returns an object, Atria wraps it as feed output data and sends it to configured outputs.

## Related Pages

* [Feed lifecycle](/atria/core-concepts/feed-lifecycle)
* [Cursors and block delay](/atria/core-concepts/cursors-and-block-delay)
* [Filters](/atria/core-concepts/filters)
* [Results](/atria/core-concepts/results)
* [Outputs](/atria/core-concepts/outputs)
* [Feed manifest](/atria/core-concepts/feed-manifest)