diff --git a/src/proxyz/train.py b/src/proxyz/train.py
index d80bb2f..47c7ed8 100644
--- a/src/proxyz/train.py
+++ b/src/proxyz/train.py
@@ -26,7 +26,10 @@
 @click.command(context_settings={'show_default': True})
 @click.argument("data_files", type=click.Path(), nargs=-1)
 @click.option(
-    "--eval_files", type=click.Path(), multiple=True, help="evaluate data files"
+    "--eval_files", type=str(), multiple=True,
+    help="Evaluation dataset(s). Format: 'name=file1,file2' for named datasets "
+    "(metrics traced separately per name), or plain 'file' (auto-named from filename). "
+    "Repeat for multiple eval sets, e.g. --eval_files casp=casp15.txt --eval_files cameo=cameo.txt",
 )
 @click.option(
     "--dataset_name",
@@ -432,9 +435,30 @@ def data_generator(data_files):
         )
         eval_dataset = None
         if args.eval_files:
-            eval_dataset = Dataset.from_generator(
-                functools.partial(data_generator, args.eval_files)
-            )
+            # Parse --eval_files into named groups: "name=file1,file2" or plain "file"
+            eval_groups = {}
+            for spec in args.eval_files:
+                if "=" in spec:
+                    name, paths_str = spec.split("=", 1)
+                    name = name.strip()
+                    files = tuple(p.strip() for p in paths_str.split(",") if p.strip())
+                else:
+                    files = (spec,)
+                    name = os.path.splitext(os.path.basename(spec))[0]
+                # De-duplicate names by appending a suffix
+                base_name = name
+                counter = 2
+                while name in eval_groups:
+                    name = f"{base_name}_{counter}"
+                    counter += 1
+                eval_groups[name] = files
+
+            eval_dataset = {
+                name: Dataset.from_generator(
+                    functools.partial(data_generator, files)
+                )
+                for name, files in eval_groups.items()
+            }
 
     # Apply tokenization
     text_col = args.text_column if args.dataset_name else "text"
@@ -443,13 +467,20 @@ def tokenize_dataset(dataset):
         return dataset.map(tokenize_function, batched=True, remove_columns=[text_col])
 
     train_dataset = tokenize_dataset(train_dataset)
-    if eval_dataset:
-        eval_dataset = tokenize_dataset(eval_dataset)
+    if eval_dataset is not None:
+        if isinstance(eval_dataset, dict):
+            eval_dataset = {k: tokenize_dataset(v) for k, v in eval_dataset.items()}
+        else:
+            eval_dataset = tokenize_dataset(eval_dataset)
 
     if args.verbose:
         print(f"--- Train dataset ---")
         print(f"Examples: {len(train_dataset):,}")
-        if eval_dataset:
+        if isinstance(eval_dataset, dict):
+            for name, ds in eval_dataset.items():
+                print(f"--- Eval dataset [{name}] ---")
+                print(f"Examples: {len(ds):,}  Files: {eval_groups.get(name, '?')}")
+        elif eval_dataset:
             print(f"--- Eval dataset ---")
             print(f"Examples: {len(eval_dataset):,}")
 
@@ -563,10 +594,22 @@ def on_log(self, args, state, control, logs=None, **kwargs):
             self.trainer._fim_cache = None
             labels, logits = cache
 
-            # Detect if this is eval or training based on log keys
-            is_eval = "eval_loss" in logs
-            prefix = "eval_" if is_eval else ""
-            loss_key = f"{prefix}loss"
+            # Detect eval vs training and determine metric prefix.
+            # With multiple eval datasets the Trainer logs per-dataset keys
+            # like "eval_casp15_loss", "eval_cameo_loss"; with a single eval
+            # dataset it logs "eval_loss".  Training logs use "loss".
+            if "eval_loss" in logs:
+                prefix = "eval_"
+            else:
+                for key in logs:
+                    if key.startswith("eval_") and key.endswith("_loss"):
+                        # prefix = "eval_<name>_" e.g. "eval_casp15_"
+                        prefix = key[: -len("loss")]  # keeps trailing "_"
+                        break
+                else:
+                    prefix = ""
+
+            loss_key = f"{prefix}loss" if prefix else "loss"
 
             # Detect FIM examples: labels start with -100
             is_fim = labels[:, 0] == -100