fix: make otel-sdk default dependency, import otel instrumentors safely

pyproject.toml

@@ -13,6 +13,7 @@ dependencies = [
     "httpx>=0.28.1",
     "Jinja2>=3.1.4",
     "openai>=1.61.1",
+    "opentelemetry-sdk>=1.38.0",
     "pillow>=11.0.0",
     "py-machineid>=0.7.0",
     "pydantic-settings>=2.9.1",
@@ -223,7 +224,6 @@ bedrock = [
 otel = [
     "prometheus-fastapi-instrumentator>=7.1.0",
     "opentelemetry-api>=1.38.0",
-    "opentelemetry-sdk>=1.38.0",
     "opentelemetry-instrumentation-fastapi>=0.59b0",
     "opentelemetry-exporter-otlp-proto-http>=1.38.0",
     "opentelemetry-instrumentation-httpx>=0.59b0",

src/askui/telemetry/otel.py

@@ -1,9 +1,5 @@
 from fastapi import FastAPI
 from opentelemetry import trace
-from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
-from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor
-from opentelemetry.instrumentation.httpx import HTTPXClientInstrumentor
-from opentelemetry.instrumentation.sqlalchemy import SQLAlchemyInstrumentor
 from opentelemetry.sdk.resources import Resource
 from opentelemetry.sdk.trace import TracerProvider
 from opentelemetry.sdk.trace.export import BatchSpanProcessor
@@ -51,6 +47,22 @@ def setup_opentelemetry_tracing(app: FastAPI, settings: OtelSettings) -> None:
         None
 
     """
+    try:
+        from opentelemetry.exporter.otlp.proto.http.trace_exporter import (  # type: ignore[import-not-found]
+            OTLPSpanExporter,
+        )
+        from opentelemetry.instrumentation.fastapi import (  # type: ignore[import-not-found]
+            FastAPIInstrumentor,
+        )
+        from opentelemetry.instrumentation.httpx import (  # type: ignore[import-not-found]
+            HTTPXClientInstrumentor,
+        )
+        from opentelemetry.instrumentation.sqlalchemy import (  # type: ignore[import-not-found]
+            SQLAlchemyInstrumentor,
+        )
+    except ImportError:
+        return
+
     resource = Resource.create(
         {
             "service.name": settings.service_name,