"Agent Substrate: the core system." Four words, and both halves are positional. Substrate names what is underneath, and core names what does not get swapped out. The claim is about depth in the stack rather than features.
The word only means something relative to what sits above it. Choosing it commits the project to being depended on rather than to being the thing you interact with.
Core parts are the ones you do not rewrite each quarter. Naming yourself core is a bet that the interface will still be right after the layers above it change.
The smallest number on the board by a wide margin, next to repos pulling four figures. Early enough that the description is genuinely all there is to read.
Concept mock, not affiliated with the project. The stack is labelled position, not architecture: the two upper layers are generic descriptions of where other tools sit, not components this project publishes. Its complete GitHub Trending description on 21 August 2026 is "Agent Substrate: the core system", and the 22 stars figure is that page's own count for the day.