The implementation language is Go, fixed by this Target's `TECHNOLOGY_STACK.md` and governed by `stack/go.md`. The program is a filter: read TOML from **stdin**, write tagged JSON to **stdout**, exit `0`. On invalid TOML, write a diagnostic to **stderr** and exit non-zero. Every TOML **value** becomes `{"type": "", "value": ""}`. basic and literal strings, then multi-line strings with their line-ending backslash and trimming rules. **Scalars** — booleans, integers (including `0x`, `0o`, `0b`, underscores), floats (including `inf`, `nan`, exponents), basic and literal strings, then **Datetimes** — offset, local datetime, local date, local time. **Scaffolding** — line handling, comments, whitespace, the stdin/stdout/exit contract, tagged JSON emission. **Keys** — bare, quoted, and dotted keys; the redefinition rules. **Inline tables and arrays** — including nesting and the TOML 1.0 restriction that inline tables are closed to later extension. **Invalid-input hardening** — control characters, bad UTF-8, duplicate keys, redefinition after an inline table, unterminated constructs. **Inline tables and arrays** — including nesting and the TOML 1.0 restriction that inline tables are closed to later extension. the TOML 1.0 restriction that inline tables are closed to later extension. **Tables** — `[table]`, `[a.b.c]` implicit creation, `[[array of tables]]`, and the rules governing which of these may follow which. `[[array of tables]]` the rules governing which of these may follow which. Every supplied valid and invalid case passes: the failed, errored, and skipped counts are all zero.