diff --git a/cacheflow/decoding.py b/cacheflow/decoding.py
new file mode 100644
index 00000000..f8d5980d
--- /dev/null
+++ b/cacheflow/decoding.py
@@ -0,0 +1,30 @@
+from typing import List
+
+
+class DecodingParams:
+
+    def __init__(
+        self,
+        n: int = 1,
+        temperature: float = 1.0,
+        top_p: float = 1.0,
+        use_beam_search: bool = False,
+        stop_token_ids: List[int] = [],
+    ) -> None:
+        assert n >= 1
+        assert temperature >= 0.0
+        assert 0.0 < top_p <= 1.0
+        if use_beam_search:
+            assert n > 1
+            assert temperature > 0.0
+            assert top_p == 1.0
+        elif temperature == 0.0:
+            # Zero temperature means greedy decoding.
+            assert n == 1
+            assert top_p == 1.0
+
+        self.n = n
+        self.temperature = temperature
+        self.top_p = top_p
+        self.use_beam_search = use_beam_search
+        self.stop_token_ids = stop_token_ids