Create compare.py

backend/app/api/compare.py

@@ -0,0 +1,40 @@
+import json
+
+from fastapi import APIRouter, Depends, Query
+from sqlalchemy.orm import Session
+
+from backend.app.db import get_db
+from backend.app.models.experiment import Experiment
+
+router = APIRouter(tags=["compare"])
+
+
+@router.get("/compare")
+def compare_experiments(
+    experiment_ids: str = Query(...),
+    db: Session = Depends(get_db),
+):
+    ids = [x.strip() for x in experiment_ids.split(",") if x.strip()]
+
+    experiments = (
+        db.query(Experiment)
+        .filter(Experiment.id.in_(ids))
+        .all()
+    )
+
+    return {
+        "experiments": [
+            {
+                "experiment_id": exp.id,
+                "dataset_id": exp.dataset_id,
+                "algorithm": exp.algorithm,
+                "status": exp.status,
+                "config": json.loads(exp.config_json or "{}"),
+                "metrics": json.loads(exp.metrics_json or "{}"),
+                "summary": json.loads(exp.summary_json or "[]"),
+                "runtime_ms": exp.runtime_ms,
+                "error_message": exp.error_message,
+            }
+            for exp in experiments
+        ]
+    }