Compatibility policy

The primary target is the Piper Python voice behavior at the pinned Piper 1.8.0 reference commit 404aefedbd74baa0bd43e451bc407a2b3aace0f5. libpiper behavior is a separate compatibility profile and is not silently mixed into the runtime.

Feature

Core

Compatibility label

Text frontend

yes

exact for tested Python profile

Native eSpeak clause API

system library

exact when the public terminator API is present

eSpeak CLI

executable required

best-effort

Raw blocks

yes, eSpeak only

reference-tested foundation

Pinyin, Japanese, Thai, Hebrew

recognized configuration values

unavailable, no provider

Arabic eSpeak

recognized voice profile

explicitly unsupported until preprocessing is implemented

Lexphon/G2Lex overlay

opt-in

override-generic-ipa or piper-espeak-frozen extension

The pinned Phase 1 corpus metadata is in benchmarks/data/core.json. It is not a golden output and cannot silently refresh. Exactness claims require reference output and dependency metadata.