If test.md contains:

From \TeX to \LaTeX.

then pandoc -t json test.md yields:

[
  {
    "unMeta": {}
  },
  [
    {
      "t": "Para",
      "c": [
        {
          "t": "Str",
          "c": "From"
        },
        {
          "t": "Space",
          "c": []
        },
        {
          "t": "RawInline",
          "c": [
            "tex",
            "\\TeX "
          ]
        },
        {
          "t": "Str",
          "c": "to"
        },
        {
          "t": "Space",
          "c": []
        },
        {
          "t": "RawInline",
          "c": [
            "tex",
            "\\LaTeX"
          ]
        },
        {
          "t": "Str",
          "c": "."
        }
      ]
    }
  ]
]

You'll notice that the space after \TeX is not being rendered as {"t":"Space","c":[]}.

Thanks, but none of the suggested fixes work: \TeX\ has the same output as \TeX, and \TeX{} yields {"t":"RawInline","c":["tex","\\TeX"]},{"t":"Str","c":"{}"},{"t":"Space","c":[]}.

Thanks, \TeX\ is almost a solution, except that \ generates a non-breaking space, not a regular space.

Yes it does.

It has a slight effect on readability though.

Great!