TOMLSMITH
Guide
Performance
Ecosystem
Playground
Guide
Performance
Ecosystem
Playground

TOML version policy

TomlSmith implements the published TOML 1.0.0 and TOML 1.1.0 specifications as separate modes. The selected version affects parsing, diagnostics, decoded values, and formatter safety checks.

Defaults

Surface Default
Rust Document::parse and FormatOptions::default TOML 1.1
Native CLI and @tomlsmith/cli TOML 1.1
Browser playground after a new or reset session TOML 1.1
tomlsmith-lsp without client configuration TOML 1.0
TomlSmith for VS Code TOML 1.0

The library, CLI, and playground use 1.1 for new standalone documents. Editor surfaces use 1.0 as a compatibility default because many ecosystem consumers still accept only 1.0. TomlSmith does not infer the language version from a filename.

Choose explicitly in integrations

  • Use Document::parse_as and set FormatOptions::target_version in reusable Rust integrations.
  • Pass --toml-version 1.0 or --toml-version 1.1 to the CLI.
  • Send tomlVersion in LSP initialization options or configuration updates.
  • Set tomlsmith.toml.version in VS Code.
  • Use TOML 1.0 whenever another tool that reads the file only supports 1.0.

Results across product surfaces are comparable only when the source, TOML version, and relevant options match. Formatting against a version other than the document's parse version performs an additional safety validation and can be refused.

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