JOE-1896)¶

Boundary: contracts for the continuous 0.0.x line. Change stays predictable and honest. For the v0.0.22 RC freeze inventory (frozen surfaces, break-reset policy, automated checks), see rc-freeze.md.

This is a greenfield 0.0.x product: there is no dual-path loader for old config sections, no deprecation lag for removed internal helpers, and no migration shims for pre-canonical layouts. Prefer delete over leave-for-compat.

Classification¶

Surface	Class	Notes
`TranscriptionError` / `AurumError`, `ErrorCategory`	stable-at-0.x	Category ids frozen; variants may grow under non-exhaustive policy
`Config`, `Config::validate`, `effective_diagnostic`	stable-at-0.x	Canonical TOML only (`[stt]`, `[cleanup]`, `[tts]`, `[providers.*]`); secrets redacted in Debug/diagnostic
`ValidatedConfig`, `AurumEngine`	stable-at-0.x	Preferred library entry; owns governor/metrics/STT(+TTS) pools
`SttContextPool` / `TtsSessionPool`	provisional	Engine-local by default; process-global helpers for CLI
`SecretString`	stable-at-0.x	Debug/Display never expose payload
`Segment` (private fields + accessors)	stable-at-0.x	`try_new` / `validate` / getters (JOE-1786)
`SampleRateHz` / `FiniteDurationSecs` / `ModelId`	provisional	Domain primitives
`TranscriptionResult::try_local` / `try_openrouter`	stable-at-0.x	Fail-closed builders
Process-global STT/TTS pools	cli default	Used when constructing providers without an engine; not a second product path
`SttResultDto` `schema_version = 1`	stable-at-0.x	Unknown future fields: ignore on read when possible; unsupported version → error
`ErrorDto` `schema_version = 1`	stable-at-0.x	Library + CLI machine JSON error envelope
`ProviderCapabilities` `schema_version = 1`	stable-at-0.x	Preflight before expensive work; optional remote fields are additive with defaults
`PartialSession`, `PcmBuffer`, `ResourceGovernor`	stable-at-0.x	Host-facing concurrency / progressive STT
C ABI (`AURUM_ABI_VERSION = 2`)	provisional	Jobs include STT/cleanup/TTS; additive status codes preferred
Internal download, remote client, postprocess	internal	May change without notice
Experimental adapters / experimental STT models	feature-gated / experimental	Not part of the stability claim

SemVer (0.0.x continuous)¶

Aurum iterates as 0.0.x patch steps. A major 1.0.0 is not planned for the current programme; production-assurance work targets v0.0.22.

PATCH (0.0.x): bugfixes, docs, additive diagnostics, non-breaking DTO fields with defaults, evidence packs, provider catalogue refresh
Breaking 0.0.x: removed public items require a CHANGELOG note (no multi-release deprecation lag)

Unknown JSON fields¶

Readers of schema_version = 1 DTOs should ignore unknown fields. Writers must not emit NaN/Inf. Unsupported schema_version values fail clearly.

Fixtures¶

STT JSON: schema_version present; see unit tests in dto / output
Config: load_from / load_from_required / redacted diagnostic / ValidatedConfig
Engine: multi-engine metrics isolation tests
ABI: aurum-ffi abi_layout tests

Release checklist¶

Review public surfaces against this document
Update classifications when the surface changes
CHANGELOG note for any breaking 0.0.x change
Run cargo test + clippy + FFI abi tests