From f2e28b8f3a10c34c4803965101ca382c1ea3bc6e Mon Sep 17 00:00:00 2001
From: Tim Schneider <tim.schneider1@tu-darmstadt.de>
Date: Wed, 10 Apr 2024 14:53:35 +0200
Subject: [PATCH] Added metadata field to VectorEnv. Implements  #1005

---
 gymnasium/vector/vector_env.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/gymnasium/vector/vector_env.py b/gymnasium/vector/vector_env.py
index 7127dd9aa..271603a9a 100644
--- a/gymnasium/vector/vector_env.py
+++ b/gymnasium/vector/vector_env.py
@@ -92,6 +92,9 @@ class VectorEnv(Generic[ObsType, ActType, ArrayType]):
         :func:`make_vec` is the equivalent function to :func:`make` for vector environments.
     """
 
+    # Set this in SOME subclasses
+    metadata: dict[str, Any] = {"render_modes": []}
+
     spec: EnvSpec | None = None
     render_mode: str | None = None
     closed: bool = False
@@ -446,6 +449,11 @@ def render_mode(self) -> tuple[RenderFrame, ...] | None:
         """Returns the `render_mode` from the base environment."""
         return self.env.render_mode
 
+    @property
+    def metadata(self) -> dict[str, Any]:
+        """Returns the `metadata` from the base environment."""
+        return self.env.metadata
+
     @property
     def np_random(self) -> np.random.Generator:
         """Returns the environment's internal :attr:`_np_random` that if not set will initialise with a random seed.