ZON serialization

ACORN supports ZON as a compact serialization of the JSON data model. ZON is a file format, not a research-metadata standard: the same Research Activity Data (RAD) schema and validation rules apply whether a record is stored as JSON, YAML, Markdown, or ZON.

Use the .zonf extension and provisional text/zonf media type. ACORN deliberately does not treat .zon as a ZON file because that extension is used by other formats.

meta{title:Example activity,keywords:"[research,metadata]"}
contact{email:researcher@example.org,name:Researcher}

The portable acorn_schema::standard::zon codec emits a deterministic strict profile: object keys and table columns are sorted, booleans use T and F, null uses null, line endings are LF, and output has no trailing whitespace or final newline. Decoding also accepts the selected aliases used by the pinned TypeScript reference implementation, including @N root-table headers, single-quoted strings, exponent numbers, and case-insensitive boolean and null aliases. Encoding always returns to the canonical form.

ACORN’s profile is pinned to upstream commit 1b5917dbbf254ba11fb217a378d8ea05a17598d2. It supports JSON primitives, objects, arrays, compound arrays, and uniform-object tables. It rejects the separate labeled v2 syntax and enforces bounded document, line, depth, array, and object sizes.

For tests/fixtures/data/valid_project/index.json, the compact JSON data is 3,018 bytes, canonical ZON is 3,302 bytes, and the checked-in pretty JSON is 4,385 bytes. These are byte-size comparisons only; token counts depend on the selected model and tokenizer.

Command-line use

Valid .zonf RAD files participate in normal discovery, checking, formatting, exporting, crosswalking, repository workflows, and GitLab review:

acorn check activity.zonf
acorn format activity.zonf
acorn export activity.json --format zon
acorn export datacite.zonf --format zon --from datacite --to dcat

--format zon writes .zonf. Check reports keep their existing console, JSON, Markdown, or YAML output formats; ZON support describes the checked input and does not add a ZON diagnostic-report format.

Model-facing prompt data

Prompt instructions remain Markdown. PromptHydrator appends the complete serializable data object once in a fenced canonical ZON block by default. Library callers can select deterministic pretty JSON with PromptDataFormat::Json when troubleshooting.

This setting changes only the text supplied to the model. ACP continues to use its official JSON-RPC wire protocol, and OpenAI-compatible APIs continue to use their JSON HTTP request envelopes; both adapters forward the already hydrated prompt body verbatim.