FAQ

Answers grounded in SPEC.md; each links the section that decides.

Why is the magic string "curtis-conversation"?

It is a version-1 compatibility legacy of the format's origin in Curtis AI Chat. It cannot change without breaking every existing file, so it stays. The format itself is vendor-neutral, and nothing in the spec favors Curtis — the spec says so directly, and the generator field exists so your app can sign what it wrote. See SPEC "File shape" and the names table in the README.

Why tolerate a BOM?

A UTF-8 byte-order mark is not JSON, but Windows editors prepend one anyway. Release 1.1.0 clarified the rule: readers MUST ignore at most one leading UTF-8 BOM — it is not part of the JSON body — and writers MUST NOT emit one. Tolerance on read, discipline on write. See SPEC "File shape".

Why zip for bulk?

Because one file is one conversation. There is no manifest, no account wrapper; a directory of conversations is a directory of files, and bulk transfer is a zip of them. No naming scheme is required — readers MUST NOT depend on file names — and readers import the valid entries and report (not silently drop) corrupted ones. The recommended curtFilename convention exists so names order chronologically and survive title edits, but it is a convenience, never an input. See SPEC "Bulk convention".

Why not just use vCon?

vCon and .curt model different domains. vCon (draft-ietf-vcon-vcon-core, IETF) targets real-time human conversations — calls, transcriptions, call-center sessions — and has no LLM-native semantics: no role vocabulary tied to model inference, no tool-call linkage, no model metadata, and no executable conformance vectors. .curt targets AI-chat fidelity in a single file with strict validation and a testable conformance ladder. Neither subsumes the other; the curt-vcon bridge maps the overlapping text subset, and its fidelity matrix shows what such a mapping drops. Full comparison: .curt vs vCon vs vendor exports.

What's the license split?

The spec, reference implementation, schema, and fixtures are MIT — as of release 1.2.0 (2026-10-14), permanently. Through 1.1.0 they were BUSL-1.1; the relicense was deliberate: a standard that requires permission to implement is not open. The Curtis applications (plugin, Porter, web, cloud) are separate works under BUSL-1.1 — the moat is in the apps, not the standard. See the README's License section.

Is an empty messages array valid?

Yes — spec-valid. Readers accept it: messages is an array in which every entry passes message validation, and an empty array trivially satisfies that. Writers should not emit one, since a conversation with no messages carries nothing. See SPEC, the conversation table, and the validation rules.