# Introducing the Nix Flake Checker, a tool for keeping your Nixpkgs inputs up to date
**URL:** https://discourse.nixos.org/t/introducing-the-nix-flake-checker-a-tool-for-keeping-your-nixpkgs-inputs-up-to-date/29415
**Category:** Links
**Created:** [June 20, 2023, 3:41pm UTC](https://discourse.nixos.org/t/introducing-the-nix-flake-checker-a-tool-for-keeping-your-nixpkgs-inputs-up-to-date/29415 "2023-06-20T15:41:42Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@lucperkins](https://discourse.nixos.org/u/lucperkins)
#### Post date: [June 20, 2023, 3:41pm UTC](https://discourse.nixos.org/t/introducing-the-nix-flake-checker-a-tool-for-keeping-your-nixpkgs-inputs-up-to-date/29415/1 "2023-06-20T15:41:42Z")
> **[Introducing the Nix Flake Checker](https://determinate.systems/posts/flake-checker)**
>
> A powerful new way to keep your Nix flakes in line with best practices.
---
### Author:  [@asymmetric](https://discourse.nixos.org/u/asymmetric)
#### Post date: [June 20, 2023, 3:51pm UTC](https://discourse.nixos.org/t/introducing-the-nix-flake-checker-a-tool-for-keeping-your-nixpkgs-inputs-up-to-date/29415/2 "2023-06-20T15:51:49Z")
> [Pinning](https://zero-to-nix.com/concepts/pinning) dependencies is quite possibly _the_ killer feature of [Nix flakes](https://zero-to-nix.com/concepts/flakes)
Maybe this could be rephrased to reflect the fact that there are other tools which aid with pinning, but that flakes is ~upstream (unlike something like niv).
---
### Author:  [@lucperkins](https://discourse.nixos.org/u/lucperkins)
#### Post date: [June 20, 2023, 3:54pm UTC](https://discourse.nixos.org/t/introducing-the-nix-flake-checker-a-tool-for-keeping-your-nixpkgs-inputs-up-to-date/29415/3 "2023-06-20T15:54:34Z")
This tool is designed to work only with flakes. It’s not clear to me that mentioning Niv or other approaches would be particularly edifying here.
---
### Author:  [@asymmetric](https://discourse.nixos.org/u/asymmetric)
#### Post date: [June 20, 2023, 4:01pm UTC](https://discourse.nixos.org/t/introducing-the-nix-flake-checker-a-tool-for-keeping-your-nixpkgs-inputs-up-to-date/29415/4 "2023-06-20T16:01:28Z")
Right, but is it true in the absolute that dependency pinning is flakes’ killer feature? Not clear to me, considering stuff like Niv exists and does this too.
The killer feature (for me at least) is that it does that while being (or having a chance of becoming) part of standard Nix, with all that this entails (see e.g. the discussion [here](https://discourse.nixos.org/t/why-are-flakes-still-experimental/29317/16)).
Meaning you don’t need to mention Niv, just scale down (or qualify) the claim a bit.
---
### Author:  [@lucperkins](https://discourse.nixos.org/u/lucperkins)
#### Post date: [June 20, 2023, 4:15pm UTC](https://discourse.nixos.org/t/introducing-the-nix-flake-checker-a-tool-for-keeping-your-nixpkgs-inputs-up-to-date/29415/5 "2023-06-20T16:15:46Z")
I think that “quite possibly” is sufficient qualification for the last paragraph of an announcement blog post. If this were a highly technical deep dive I’d be more inclined to agree.