>>309425140
It may never be released publicly
https://arstechnica.com/gaming/2020/01/what-we-learned-from-valves-half-life-alyx-qa-on-reddit/
>[..] . While Valve has told fans that some VR-specific tools will be opened up for tinkerers when the game launches, the same won't happen for the "full" SDK. "This is how we've done SDKs in our previous Source 1 titles as well," Valve said. "Making the game takes precedence, and after that's done, we start looking at what's next."