[ciaranmn]

1) The spec says that a block package includes its source code, and the block hub seems to be a browser of block packages, but it doesn't give me the full view into said block packages. Is there a reason for this? Is it on the to-do list?

It's on the to-list indeed - we are going to add links to the source of blocks. The package for distribution will typically be minified and less illuminating, although we can look to expose that too (as well as making it available for request via the API when actually loading a block).

2) What's going on with the type signatures here?

The type signatures on functions in the spec definitely need cleaning up to be consistent and more helpful. They are pseudo-code. There are TypeScript types for them (https://github.com/blockprotocol/blockprotocol/blob/main/pac...) which won't be much use to you, but I am including in case they are of someone else.

The schema you mention in the Hub is autogenerated from the TypeScript interface for the block, which can lead to weird artefacts of the sort you identify. We need to add custom codegen to better handle this. It should valid JSON Schema.