diff --git a/.github/benchmark-models.yml b/.github/benchmark-models.yml
index be17b9a4..4fc2be69 100644
--- a/.github/benchmark-models.yml
+++ b/.github/benchmark-models.yml
@@ -33,6 +33,8 @@ models:
   #- openrouter/deepseek/deepseek-v3.2
 
   # Minimax
+  - openrouter/minimax/minimax-m3
+  - openrouter/minimax/minimax-m2.7
   - openrouter/minimax/minimax-m2.1
   - openrouter/minimax/minimax-m2.5
 
diff --git a/scripts/lib_agent.py b/scripts/lib_agent.py
index ec2d3c48..b8c9e0b8 100644
--- a/scripts/lib_agent.py
+++ b/scripts/lib_agent.py
@@ -36,6 +36,53 @@ class ModelValidationError(Exception):
 # Valid thinking levels for OpenClaw reasoning depth
 VALID_THINKING_LEVELS = ("off", "minimal", "low", "medium", "high", "xhigh", "adaptive")
 
+_MINIMAX_OPENAI_BASE_URLS = {
+    "https://api.minimax.io/v1",
+    "https://api.minimaxi.com/v1",
+}
+
+_MINIMAX_MODEL_METADATA: dict[str, dict[str, Any]] = {
+    "MiniMax-M3": {
+        "reasoning": True,
+        "input": ["text", "image", "video"],
+        "contextWindow": 1_000_000,
+        "cost": {
+            "input": 0.6,
+            "output": 2.4,
+            "cacheRead": 0.12,
+        },
+    },
+    "MiniMax-M2.7": {
+        "reasoning": True,
+        "input": ["text"],
+        "contextWindow": 204_800,
+        "cost": {
+            "input": 0.3,
+            "output": 1.2,
+            "cacheRead": 0.06,
+            "cacheWrite": 0.375,
+        },
+    },
+}
+
+
+def _custom_model_definition(model_id: str, base_url: str) -> dict[str, Any]:
+    definition: dict[str, Any] = {
+        "id": model_id,
+        "name": model_id,
+        "reasoning": False,
+        "input": ["text"],
+        "contextWindow": 200_000,
+        "maxTokens": 8192,
+    }
+
+    if base_url.rstrip("/") in _MINIMAX_OPENAI_BASE_URLS:
+        metadata = _MINIMAX_MODEL_METADATA.get(model_id)
+        if metadata:
+            definition.update(metadata)
+
+    return definition
+
 
 def _coerce_subprocess_output(value: Any) -> str:
     if value is None:
@@ -325,16 +372,7 @@ def ensure_agent_exists(
             "baseUrl": base_url,
             "apiKey": key_ref,
             "api": "openai-completions",
-            "models": [
-                {
-                    "id": model_id,
-                    "name": model_id,
-                    "reasoning": False,
-                    "input": ["text"],
-                    "contextWindow": 200000,
-                    "maxTokens": 8192,
-                }
-            ],
+            "models": [_custom_model_definition(model_id, base_url)],
         }
         data["defaultProvider"] = "custom"
         data["defaultModel"] = model_id
diff --git a/tests/test_lib_agent_models.py b/tests/test_lib_agent_models.py
new file mode 100644
index 00000000..64ee12d6
--- /dev/null
+++ b/tests/test_lib_agent_models.py
@@ -0,0 +1,102 @@
+from __future__ import annotations
+
+import json
+import subprocess
+import sys
+import unittest
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from unittest.mock import patch
+
+
+ROOT = Path(__file__).resolve().parents[1]
+SCRIPTS_DIR = ROOT / "scripts"
+if str(SCRIPTS_DIR) not in sys.path:
+    sys.path.insert(0, str(SCRIPTS_DIR))
+
+from lib_agent import _custom_model_definition, ensure_agent_exists  # noqa: E402
+
+
+class CustomModelDefinitionTests(unittest.TestCase):
+    def test_minimax_m3_uses_global_endpoint_metadata(self) -> None:
+        definition = _custom_model_definition(
+            "MiniMax-M3",
+            "https://api.minimax.io/v1",
+        )
+
+        self.assertEqual(definition["contextWindow"], 1_000_000)
+        self.assertEqual(definition["input"], ["text", "image", "video"])
+        self.assertTrue(definition["reasoning"])
+        self.assertEqual(
+            definition["cost"],
+            {"input": 0.6, "output": 2.4, "cacheRead": 0.12},
+        )
+
+    def test_minimax_m27_uses_china_endpoint_metadata(self) -> None:
+        definition = _custom_model_definition(
+            "MiniMax-M2.7",
+            "https://api.minimaxi.com/v1/",
+        )
+
+        self.assertEqual(definition["contextWindow"], 204_800)
+        self.assertEqual(definition["input"], ["text"])
+        self.assertTrue(definition["reasoning"])
+        self.assertEqual(
+            definition["cost"],
+            {
+                "input": 0.3,
+                "output": 1.2,
+                "cacheRead": 0.06,
+                "cacheWrite": 0.375,
+            },
+        )
+
+    def test_unknown_endpoint_keeps_generic_defaults(self) -> None:
+        definition = _custom_model_definition(
+            "MiniMax-M3",
+            "https://example.com/v1",
+        )
+
+        self.assertEqual(
+            definition,
+            {
+                "id": "MiniMax-M3",
+                "name": "MiniMax-M3",
+                "reasoning": False,
+                "input": ["text"],
+                "contextWindow": 200_000,
+                "maxTokens": 8192,
+            },
+        )
+
+    def test_ensure_agent_writes_minimax_metadata(self) -> None:
+        completed = subprocess.CompletedProcess(args=[], returncode=0, stdout="", stderr="")
+
+        with TemporaryDirectory() as tmpdir:
+            root = Path(tmpdir)
+            store_dir = root / "agents" / "bench-minimax-m3"
+            workspace = root / "workspace"
+
+            with patch("lib_agent.subprocess.run", return_value=completed), patch(
+                "lib_agent._get_agent_store_dir",
+                return_value=store_dir,
+            ), patch("lib_agent.Path.home", return_value=root):
+                created = ensure_agent_exists(
+                    "bench-minimax-m3",
+                    "MiniMax-M3",
+                    workspace,
+                    base_url="https://api.minimax.io/v1",
+                    api_key="test-key",
+                )
+
+            self.assertTrue(created)
+            config = json.loads((store_dir / "agent" / "models.json").read_text("utf-8"))
+            model = config["models"]["providers"]["custom"]["models"][0]
+            self.assertEqual(
+                model,
+                _custom_model_definition("MiniMax-M3", "https://api.minimax.io/v1"),
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()