[Gaming](https://leakly.com/gaming/)

[Corroborated]

# A playable build of Valve's canceled Portal prequel F-Stop is circulating

Fans rebuilt it from a massive Steam data dump. Valve has not commented.

Leaked on 31 October 2026

![Screenshot of @gabefollower's X post: There was another Valve leak. Someone shared maps from F-Stop, the canceled Portal sequel. Compiled with all the previous leaks, F-Stop is f](https://leakly.com/assets/images/portal-prequel-f-stop-playable-build-hero.jpg)

@gabefollower's post on X, with counts as of 09 Nov 2026 12:49 UTC. [Live post on X](https://x.com/gabefollower/status/2116621378069901713)

Nearly 20 years after it was canceled, Valve's camera-based Portal prequel F-Stop is no longer lost media, [The Verge](https://www.theverge.com/games/1024206/playable-portal-prequel-f-stop-leak) reported on November 1. Fans have pieced together a playable version, with most assets taken from a 12-terabyte data dump.

Gabe Follower (@gabefollower), which tracks Valve, shared footage of the build on X. The Verge reports that the build shows the camera mechanic the project was known for.

> **‎Gabe Follower** @gabefollower
>
> There was another Valve leak. Someone shared maps from F-Stop, the canceled Portal sequel. Compiled with all the previous leaks, F-Stop is fully playable with all code, assets, and now maps available to the public. https://t.co/4Uqeb7GApZ
>
> 10,267 likes · 717 reposts · counts as of 09 Nov 2026, 12:49 UTC
>
> — ‎Gabe Follower (@gabefollower) [October 31, 2026](https://twitter.com/gabefollower/status/2116621378069901713)

not in our leaker index

The Verge also reported on the build. Valve has not commented, and the files come from leaked material.

## What we know

* A playable F-Stop build is circulating.
* Assets came from a 12-terabyte data dump.

## What we don't know

* Whether Valve will act against the build.

## What would confirm it

A Valve statement.

## Sources

* [Original X post by @gabefollower](https://x.com/gabefollower/status/2116621378069901713)
* [A fully playable version of Portal prequel F-Stop leaked | The Verge](https://www.theverge.com/games/1024206/playable-portal-prequel-f-stop-leak)

[Corroborated]

## What happened later

The Verge also reported on the build. Valve has not commented, and the files come from leaked material.

Status key: [how we label leaks](https://leakly.com/editorial-guidelines/#status) · [Corrections](https://leakly.com/corrections/) · [Contact](https://leakly.com/contact/)