Highlights TOON (Token-Oriented Object Notation) in .toon files. TOON is a compact, indentation-based encoding of the JSON data model for LLM input.
code --install-extension toon-format.toonVSCodium and other editors that use Open VSX install it from there.
Open any .toon file, such as:
users[2]{id,name,role}:
1,Ada,admin
2,Bob,user
The grammar scopes:
- Keys, array headers with their length and delimiter, and field lists – including nested field groups and keyed tabular headers
- Numbers,
true,false,null, empty arrays, and unquoted and quoted strings, with invalid escape sequences flagged - Delimiters in inline arrays and rows, list item markers, and full-line
#comments
Folding follows indentation, and pressing Enter after a line ending in : indents the next one.
Targets TOON spec v4.4.
- Specification: SPEC.md – Normative rules and conformance checklists
- Format Overview: toonformat.dev – Every form with examples
- Other Implementations: toonformat.dev – TOON in other languages
See CONTRIBUTING.md for the development setup and pull request guidelines.
MIT License © 2025-PRESENT Vishal Raut, Timofey Elsesser, and Johann Schopplich