---
title: upstream
framework: combine
role: symbol
role_heading: Instance Property
path: combine/publishers/timeout/upstream
---

# upstream

The publisher from which this publisher receives elements.

## Declaration

```swift
let upstream: Upstream
```

## See Also

### Inspecting publisher properties

- [interval](combine/publishers/timeout/interval.md)
- [scheduler](combine/publishers/timeout/scheduler.md)
- [options](combine/publishers/timeout/options.md)
- [customError](combine/publishers/timeout/customerror.md)