Glossary

The terms this wiki uses, precisely.

Alias — any inbound spelling that resolves to a language. Stored normalised; globally unique. Aliases and Normalisation

Base language — a language whose canonical code carries no qualifier: en, de, ceb. Its own code is what providers receive; it needs no mapping. Note this means no qualifier, not two letters.

BCP-47 — the IETF standard for language tags: language-Script-REGION, e.g. zh-Hans-CN. The casing convention this service canonicalises to.

Canonical code — the one spelling of a language this service uses and returns. Store this.

Derived — an answer produced by the fallback ladder rather than an explicit mapping. Correct and usable, but not curated. Anything with match other than exact.

Effective code — what a provider would actually receive for a language, whether explicit or derived. ?effective=true.

Explicit mapping — a configured (provider, language) row. Yields match: exact.

Fallback policy — per-provider: what to answer for a regional language with no explicit row. base_language, passthrough or strict. Fallback Policies

Homoglyph — a character that renders identically to another, like Cyrillic с (U+0441) and ASCII c. Normalisation repairs the ones that would otherwise make a code unmatchable. Aliases and Normalisation

Lookup key — the normalised form of a code: lowercase, - separated. What aliases are stored and matched as.

match — how an answer was reached: exact, variant, canonical, base_language, passthrough. Resolution Ladder

Provider — a translation engine, identified by the same code provider_credentials uses: deepl_api, openai_api.

Provider alias — another identifier that addresses the same provider, such as the short name deepl. Listed in aliases on GET /v1/providers/{code}.

Regional language — a language whose canonical code carries a script, a region or both: pt-BR, zh-Hans, sr-Latn-RS. The ones providers disagree about.

Unsupported pair — a (provider, language) pair recorded as not working. Answers supported: false with code: null. A statement of fact about that pair, not a fallback.

Vendor — the company behind one or more providers. Google Cloud is the vendor of both google_translate and gemini_api.