---
title: pop
summary: The three-character identifying code of the Fastly POP in which the current instance is running.
url: https://www.fastly.com/documentation/reference/compute/sdks/rust/fastly/compute_runtime/fn.pop/
---

**Kind:** Function  
**Module:** [compute_runtime](https://www.fastly.com/documentation/reference/compute/sdks/rust/fastly/compute_runtime/)  
**Package:** fastly 0.13.1  
**Source:** https://docs.rs/crate/fastly/0.13.1/source/src/compute_runtime.rs#76

```rust
fn pop() -> &'static str
```

The three-character identifying code of the [Fastly POP](https://www.fastly.com/documentation/guides/concepts/pop/) in which the current instance is
running.

Equivalent to the "FASTLY_POP" environment variable and to [`server.datacenter`](https://www.fastly.com/documentation/reference/vcl/variables/server/server-datacenter/) in VCL.

**Returns**

`&str`