diff --git a/openrag/core/evaluation/runner.py b/openrag/core/evaluation/runner.py
new file mode 100644
index 000000000..e1ec48886
--- /dev/null
+++ b/openrag/core/evaluation/runner.py
@@ -0,0 +1,67 @@
+"""Port for handing an evaluation run to the worker layer.
+
+``EvaluationService`` owns the orchestration around a run — provisioning the
+throwaway partition and the service-user token, enforcing one-run-at-a-time,
+recording the queued row. The run *itself* (upload the corpus over HTTP, shell
+out to promptfoo, fold the outputs into metrics) executes inside the
+``EvalRunner`` Ray actor.
+
+Defining the three operations the orchestrator needs on a dedicated port keeps
+it Ray-free — the Phase 9 rule that all Ray code lives under
+``services/workers/`` (``docs/refactoring/REFACTORING_STRATEGY_v1.md``). The
+adapter in ``services/workers/eval_dispatcher.py`` binds this to the actor;
+tests bind it to a fake.
+
+No Ray types cross this boundary — only plain strings, mappings and bools.
+"""
+
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import TYPE_CHECKING, Any
+
+if TYPE_CHECKING:
+    from collections.abc import Mapping, Sequence
+
+
+class EvaluationRunner(ABC):
+    """Operations the evaluation orchestrator needs from the worker layer."""
+
+    @abstractmethod
+    async def is_busy(self) -> bool:
+        """Whether a run currently occupies the runner.
+
+        Doubles as the orchestrator's liveness probe, so an implementation
+        must raise rather than hang when the worker cannot be reached.
+        """
+        ...
+
+    @abstractmethod
+    async def dispatch(
+        self,
+        *,
+        run_id: str,
+        partition: str,
+        token: str,
+        api_base_url: str,
+        corpus_dir: str,
+        cases: Sequence[Mapping[str, Any]],
+    ) -> None:
+        """Hand a queued run to the worker.
+
+        Fire-and-forget: the worker owns the run from here and records its own
+        terminal status, so this returns as soon as the work is accepted.
+        """
+        ...
+
+    @abstractmethod
+    async def cancel(self, run_id: str) -> bool:
+        """Ask the worker to abandon a run.
+
+        Returns ``False`` when no worker owns ``run_id`` — the orchestrator
+        reaps the orphaned row itself in that case.
+        """
+        ...
+
+
+__all__ = ["EvaluationRunner"]