diff --git a/src/tasso/handlers/external.py b/src/tasso/handlers/external.py
index 5b8bfdd..60a0f17 100644
--- a/src/tasso/handlers/external.py
+++ b/src/tasso/handlers/external.py
@@ -1,5 +1,6 @@
 """Handlers for the app's external root, ``/tasso/``."""
 
+import random
 from typing import Annotated
 
 from fastapi import APIRouter, Depends
@@ -10,8 +11,11 @@
 
 from ..config import config
 from ..models.classification import Classification
+from ..models.classification_run import ClassificationRun
 from ..models.index import Index
+from ..models.subject import Subject
 from ..storage.classification import ClassificationStore
+from ..storage.classification_run import ClassificationRunStore
 from ..storage.subject import SubjectStore
 
 __all__ = ["external_router", "get_index"]
@@ -108,3 +112,52 @@ async def put_classification(
     await db_session_dependency.aclose()
 
     return classification
+
+
+@external_router.get(
+    "/unclassified_subject",
+    summary="Return a subject that needs classification.",
+)
+async def get_unclassified_subject(
+    logger: Annotated[BoundLogger, Depends(logger_dependency)],
+) -> Subject | None:
+    await db_session_dependency.initialize(
+        config.database_url, config.database_password
+    )
+
+    async for db_session in db_session_dependency():
+        store = SubjectStore(db_session)
+        run_store = ClassificationRunStore(db_session)
+
+    runs = await run_store.get_active_runs()
+    if len(runs) == 0:
+        return None
+    elif len(runs) == 1:
+        run = runs[0]
+    else:
+        # choose a run at random.
+        run = random.choice(runs)  # noqa: S311
+
+    # this needs to not be hardcoded.
+    user_id = "dfad48bd59404103ba9c668e47f4c700"
+
+    return await store.get_unclassified(
+        user_id, run.run_id, run.max_classifications
+    )
+
+
+@external_router.get(
+    "/active_runs",
+    summary="Return runs that are active.",
+)
+async def get_active_runs(
+    logger: Annotated[BoundLogger, Depends(logger_dependency)],
+) -> list[ClassificationRun] | None:
+    await db_session_dependency.initialize(
+        config.database_url, config.database_password
+    )
+
+    async for db_session in db_session_dependency():
+        run_store = ClassificationRunStore(db_session)
+
+    return await run_store.get_active_runs()
diff --git a/src/tasso/storage/classification_run.py b/src/tasso/storage/classification_run.py
index d97c140..0c1a709 100644
--- a/src/tasso/storage/classification_run.py
+++ b/src/tasso/storage/classification_run.py
@@ -3,7 +3,9 @@
 from typing import Annotated
 
 from fastapi import Depends
+from safir.datetime import current_datetime
 from safir.dependencies.db_session import db_session_dependency
+from sqlalchemy import select
 from sqlalchemy.ext.asyncio import async_scoped_session
 
 from ..models.classification_run import ClassificationRun
@@ -34,3 +36,28 @@ def __init__(
             storage=SQLClassificationRun,
             primary_key="run_id",
         )
+
+    async def get_active_runs(self) -> list[ClassificationRun]:
+        """Return classification runs which are active.
+
+        Returns
+        -------
+        list of ClassificationRun
+        """
+        time_now = current_datetime()
+
+        stmt = select(self.storage).where(
+            (
+                (SQLClassificationRun.time_start <= time_now)
+                | SQLClassificationRun.time_start.is_(None)
+            ),
+            (
+                (SQLClassificationRun.time_stop > time_now)
+                | SQLClassificationRun.time_stop.is_(None)
+            ),
+        )
+
+        print(stmt)
+        async with self._session.begin():
+            result = await self._session.execute(stmt)
+        return [self.model.model_validate(res[0]) for res in result.all()]
diff --git a/src/tasso/storage/subject.py b/src/tasso/storage/subject.py
index caf0929..2d9444a 100644
--- a/src/tasso/storage/subject.py
+++ b/src/tasso/storage/subject.py
@@ -5,9 +5,11 @@
 from fastapi import Depends
 from lsst.resources import ResourcePath
 from safir.dependencies.db_session import db_session_dependency
+from sqlalchemy import select
 from sqlalchemy.ext.asyncio import async_scoped_session
 
 from ..models.subject import Subject
+from ..schema import Classification as SQLClassification
 from ..schema import Subject as SQLSubject
 from .base import BaseStore
 
@@ -47,3 +49,45 @@ def get_blob(self, subject: Subject) -> bytes:
         file_uri = ResourcePath(subject.uri)
 
         return file_uri.read()
+
+    async def get_unclassified(
+        self, user_id: str, run_id: str, max_classifications: int
+    ) -> Subject | None:
+        """Return a subject for classification.
+
+        Choose one at random from the specified run which has fewer than the
+        specified numbers of classifications and is not yet classified
+        by the user.
+
+        Parameters
+        ----------
+        user_id
+           The user performing the classification.
+        run_id
+           The classification run to search for subjects.
+        max_classifiations
+            The number of classifications each subject should receive.
+        """
+        stmt = (
+            select(SQLSubject)
+            .where(
+                SQLSubject.run_id == run_id,
+                SQLSubject.n_classifications < max_classifications,
+            )
+            .outerjoin(SQLClassification)
+            .where(
+                (SQLClassification.user_id != user_id)
+                | SQLClassification.user_id.is_(None)
+            )
+        )
+
+        print(stmt)
+
+        async with self._session.begin():
+            result = await self._session.execute(stmt)
+            value = result.one_or_none()
+            print(value)
+            if value is None:
+                return None
+            else:
+                return self.model.model_validate(value[0])