I am having similar issues. Based on the error message, it does not even make it to that asset property. Fails on the q.literal('image')

Just looking at the sample test data, it would seem that markDefs expected to be inside a block still...

Based on my research: declaring custom types, such as this image example is not yet supported by groqd

If I have time I may implement something.

Here's a demonstration of how you might write it with the existing API:

https://codesandbox.io/p/sandbox/content-blocks-with-images-i7758q?file=%2Fsrc%2FApp.tsx&selection=%5B%7B%22endColumn%22%3A6%2C%22endLineNumber%22%3A32%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A17%7D%5D

Any solution @fschroiff?
I'm having some issues using sanityImage inside a content block, the PortableText tells me that _key needs to be string | undefined and not string | null (this for my images options inside content block).

Here's a demonstration of how you might write it with the existing API:

https://codesandbox.io/p/sandbox/content-blocks-with-images-i7758q?file=%2Fsrc%2FApp.tsx&selection=%5B%7B%22endColumn%22%3A6%2C%22endLineNumber%22%3A32%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A17%7D%5D

Hey @fritz-c
For me this isn't working. Any idea how to use it and solve the problem on Portable Text?

Closing as stale. Please reopen if we need further discussion on the original issues.

Not to reopen, but to perhaps provide a solution:

export const imageBlockSelection = {
  _type: q.literal('image'),
  alt: q.string(),
  caption: q.string(),
  asset: q.object({
    _ref: q.string(),
  }),
};

content: q('content')
      .filter()
      .select({
        '_type == "block"': ['{...}', q.contentBlock()],
        '_type == "image"': imageBlockSelection,
        'default': {
          _key: q.string(),
          _type: ['"unsupported"', q.literal('unsupported')],
          unsupportedType: ['_type', q.string()],
        },
      }),