Added sunbird provider

backend/providers/__init__.py

@@ -13,7 +13,7 @@ from providers.base import ProviderInfo, TranslationProvider
 from providers.gemini import GeminiProvider
 from providers.groq import GroqProvider, GroqQwenProvider
 from providers.madlad import MADLADProvider
-from providers.nllb import NLLBProvider
+from providers.nllb import NLLBProvider, SunbirdNLLBProvider
 from providers.ollama import OllamaProvider
 
 _PROVIDERS: list[TranslationProvider] = [
@@ -26,6 +26,7 @@ _PROVIDERS: list[TranslationProvider] = [
         ),
         hf_model=os.environ.get("HF_MODEL_1_3B", "facebook/nllb-200-distilled-1.3B"),
     ),
+    SunbirdNLLBProvider(),
     MADLADProvider(),
     OllamaProvider(),
     GeminiProvider(),

backend/providers/nllb.py

@@ -1,8 +1,4 @@
-"""NLLB-200 engine — local inference via CTranslate2 (int8).
-
-Light enough to run on a free HuggingFace Spaces CPU. Heavy objects load lazily
-on first use and are shared across requests.
-"""
+"""NLLB-200 & Sunbird NLLB engines — local inference via CTranslate2 (int8)."""
 
 from __future__ import annotations
 
@@ -81,3 +77,67 @@ class NLLBProvider(TranslationProvider):
         for line in text.split("\n"):
             out.append(self._translate_line(line, src, tgt) if line.strip() else "")
         return "\n".join(out)
+
+
+# Sunbird-specific language code mapping
+SUNBIRD_LANGUAGES = {
+    "eng": "English",
+    "ach": "Acholi",
+    "lgg": "Lugbara",
+    "lug": "Luganda",
+    "nyn": "Runyankole",
+    "teo": "Ateso",
+}
+
+# Auto-map standard FLORES-200 codes to Sunbird 3-letter codes
+SUNBIRD_CODE_MAP = {
+    "eng_Latn": "eng",
+    "ach_Latn": "ach",
+    "lgg_Latn": "lgg",
+    "lug_Latn": "lug",
+    "nyn_Latn": "nyn",
+    "teo_Latn": "teo",
+}
+
+
+class SunbirdNLLBProvider(NLLBProvider):
+    description = "Sunbird NLLB-200 (3.3B) fine-tune · Ugandan languages & English"
+
+    def __init__(
+        self,
+        provider_id: str = "sunbird_3_3b",
+        name: str = "Sunbird NLLB (3.3B)",
+        model_dir: str = os.environ.get(
+            "CT2_MODEL_DIR_SUNBIRD", "/data/models/sunbird-nllb-3.3b-int8"
+        ),
+        hf_model: str = os.environ.get(
+            "HF_MODEL_SUNBIRD", "Sunbird/translate-nllb-3.3b-salt"
+        ),
+    ) -> None:
+        super().__init__(
+            provider_id=provider_id,
+            name=name,
+            model_dir=model_dir,
+            hf_model=hf_model,
+        )
+
+    def _normalize_lang(self, code: str) -> str:
+        """Converts FLORES codes (e.g. 'lug_Latn') or 3-letter codes ('lug') to Sunbird format."""
+        if code in SUNBIRD_CODE_MAP:
+            return SUNBIRD_CODE_MAP[code]
+        if code in SUNBIRD_LANGUAGES:
+            return code
+        raise ValueError(
+            f"Unsupported language code '{code}' for Sunbird NLLB. "
+            f"Supported codes: {list(SUNBIRD_LANGUAGES.keys())}"
+        )
+
+    def translate(self, text: str, src: str, tgt: str, api_key: str | None = None) -> str:
+        src_code = self._normalize_lang(src)
+        tgt_code = self._normalize_lang(tgt)
+
+        self._ensure_loaded()
+        out = []
+        for line in text.split("\n"):
+            out.append(self._translate_line(line, src_code, tgt_code) if line.strip() else "")
+        return "\n".join(out)