feat(sdk): add otel support

README.md

@@ -185,6 +185,24 @@ events the SDK emits through its normal event-construction flow. The default
 SDK sink remains the OSS path to the Agent Control server. To use registered
 or named custom sinks, set `observability_sink_name` explicitly.
 
+The SDK also includes a built-in OpenTelemetry sink. Install the OTEL extra,
+select the `otel` sink, and configure the OTLP exporter through Agent Control
+settings or environment variables:
+
+```bash
+uv pip install "agent-control-sdk[otel]"
+export AGENT_CONTROL_OBSERVABILITY_SINK_NAME=otel
+export AGENT_CONTROL_OTEL_ENABLED=true
+export AGENT_CONTROL_OTEL_ENDPOINT=http://localhost:4318/v1/traces
+export AGENT_CONTROL_OTEL_HEADERS='{"authorization":"Bearer demo-token"}'
+export AGENT_CONTROL_OTEL_SERVICE_NAME=awesome-bot
+```
+
+If the `otel` sink is selected without an OTLP endpoint/exporter configured,
+the OTEL path stays inert and the default OSS SDK-to-server behavior still
+remains unchanged unless `observability_sink_name` is explicitly switched away
+from `default`.
+
 Next, create a control in Step 4, then run the setup and agent scripts in
 order to see blocking in action.
 

sdks/python/pyproject.toml

@@ -39,6 +39,11 @@ Repository = "https://github.com/yourusername/agent-control"
 strands-agents = ["strands-agents>=1.26.0"]
 google-adk = ["google-adk>=1.0.0"]
 galileo = ["agent-control-evaluator-galileo>=3.0.0"]
+otel = [
+    "opentelemetry-api>=1.24.0",
+    "opentelemetry-sdk>=1.24.0",
+    "opentelemetry-exporter-otlp-proto-http>=1.24.0",
+]
 
 [dependency-groups]
 dev = [

sdks/python/src/agent_control/__init__.py

@@ -112,6 +112,7 @@ async def handle_input(user_message: str) -> str:
     unregister_control_event_sink_factory,
     write_events,
 )
+from .otel_sink import control_event_to_otel_span
 from .tracing import (
     get_current_span_id,
     get_current_trace_id,
@@ -1380,6 +1381,7 @@ async def main():
     "write_events",
     "shutdown_observability",
     "is_observability_enabled",
+    "control_event_to_otel_span",
     "get_event_batcher",
     "get_event_sink",
     "get_registered_control_event_sink_factory_names",

sdks/python/src/agent_control/observability.py

@@ -28,6 +28,12 @@
 Configuration (Environment Variables):
     # Observability (event batching)
     AGENT_CONTROL_OBSERVABILITY_ENABLED: Enable observability (default: true)
+    AGENT_CONTROL_OBSERVABILITY_SINK_NAME: Selected control-event sink (default: default)
+    AGENT_CONTROL_OBSERVABILITY_SINK_CONFIG: JSON config for the selected sink
+    AGENT_CONTROL_OTEL_ENABLED: Enable the built-in OTEL sink (default: false)
+    AGENT_CONTROL_OTEL_ENDPOINT: OTLP HTTP endpoint for exported control-event spans
+    AGENT_CONTROL_OTEL_HEADERS: JSON object of OTLP exporter headers
+    AGENT_CONTROL_OTEL_SERVICE_NAME: OTEL service.name for emitted spans
     AGENT_CONTROL_BATCH_SIZE: Max events per batch (default: 100)
     AGENT_CONTROL_FLUSH_INTERVAL: Seconds between flushes (default: 5.0)
     AGENT_CONTROL_SHUTDOWN_JOIN_TIMEOUT: Seconds to wait for worker shutdown (default: 5.0)
@@ -75,6 +81,8 @@
 if TYPE_CHECKING:
     from agent_control_models import ControlExecutionEvent
 
+from .otel_sink import OTEL_CONTROL_EVENT_SINK_NAME, create_otel_control_event_sink
+
 # =============================================================================
 # Logger Setup - Standard Library Pattern
 # =============================================================================
@@ -820,6 +828,17 @@ def get_stats(self) -> dict:
 _used_custom_event_sinks_lock = threading.Lock()
 
 
+def _register_builtin_control_event_sink_factories() -> None:
+    """Ensure built-in named sink factories are available."""
+    _named_event_sink_factories.register(
+        OTEL_CONTROL_EVENT_SINK_NAME,
+        create_otel_control_event_sink,
+    )
+
+
+_register_builtin_control_event_sink_factories()
+
+
 class _BatcherControlEventSink(BaseControlEventSink):
     """Default SDK sink backed by the existing queue-based EventBatcher."""