Lexphon

Lexphon is a generic, lexicon-driven phonemizer and CLI built on G2Lex. It consumes released pronunciation assets and returns normalized IPA without producing Kokoro phonemes.

g2lex-data producer -> G2Lex storage -> Lexphon runtime -> application adapter

The ownership boundary is deliberate:

• g2lex-data obtains, transforms, validates, licenses, and publishes immutable data releases.
• G2Lex stores and queries typed lexicon data.
• Lexphon explicitly installs, verifies, selects, and consumes released assets.
• KokoroG2P or another application converts generic IPA to its model-specific output.

Lexphon must never contain source acquisition or G2Lex build recipes for production dictionaries.

Package layout

There is intentionally no src/ directory. The import package lives at ./lexphon.

Install for development

python -m pip install -e ".[dev]"
pytest

Data management

Catalog access and downloads are explicit. DataStore.install() is the network-capable provisioning operation. Phonemizer, lookup, token phonemization, rendering, and local store inspection never fetch a catalog or download a lexicon.

lexphon data available de-DE
lexphon data install de-de:gold
lexphon data list
lexphon data info de-de:gold
lexphon data verify de-de:gold
lexphon data remove de-de:gold

Use --catalog PATH_OR_URL and --data-home PATH for a local release or alternate store. Installation downloads the manifest first, verifies manifest and asset hashes and sizes, checks catalog and manifest identity, opens the G2Lex asset, and atomically activates a complete version. Installed metadata is sufficient for offline use and a copied store can be opened without the catalog.

The production German assets are de-de:gold, de-de:crane, de-de:espeak, and de-de:olaph. English CMUdict is available as en-us:cmudict. Membership assets can be installed for inventory use but cannot be selected as pronunciation layers.

Data release versions and the Lexphon Python package version are independent. Pin the data catalog or release during provisioning, and pin the Python dependency separately.

CLI

lexphon -v de-DE "Die Leute kommen."
lexphon -v de-DE --lexicon de-de:crane "Die Leute kommen."
lexphon -v de-DE --lexicon de-de:crane --tag DET "die"
lexphon -v en-US --lexicon en-us:cmudict --json "read"

JSON output contains the rendered IPA plus structured token fields: original text, pronunciation, source category, output alphabet, source encoding, logical lexicon ID, matched key, ordered IPA variants, selector tag, known status, and punctuation status.

Optional standalone fallback is explicit:

lexphon -v de-DE --fallback espeak "unbekannteswort"

Fallback is disabled by default. Unknown tokens remain visible to downstream applications.

Python API

from lexphon import DataStore, Phonemizer

store = DataStore()
with Phonemizer(
    "de-DE",
    lexicons=["de-de:gold"],
    store=store,
    fallback=None,
) as g2p:
    result = g2p.phonemize_tokens("Die Leute")
    for token in result.tokens:
        print(token.text, token.pronunciation, token.source, token.lexicon_id)

phonemize_tokens() is the integration API. It preserves token-level provenance, selectors, variants, punctuation, and unknown words. IPA is normalized to Unicode NFC. ARPABET and CMU-style pronunciations are converted deterministically to IPA. Unsupported alphabets and invalid pronunciation tokens raise stable Lexphon exceptions.

KokoroG2P boundary

KokoroG2P should import Lexphon's Python API, use fallback=None, convert returned IPA using its model-specific vocabulary, and apply its own fallback, stress, ratings, and diagnostics policy. Lexphon does not import KokoroG2P, perform Kokoro validation, or download dictionaries during phonemization.