# 22-fetchers-and-fixed-output

This example shows a pinned fetcher with `fetchurl`.

It includes:

- one upstream tarball fetched with `fetchurl`,
- a declared content hash,
- a small package that consumes the fetched file, and
- a check that verifies the tarball hash and contents.

Useful commands:

```bash
nix build
./result/bin/show-fetched-hello-source

nix run
nix flake check
```