diff --git a/src/plugin_runtime/capabilities/registry.py b/src/plugin_runtime/capabilities/registry.py
index ead5876a..96b190b4 100644
--- a/src/plugin_runtime/capabilities/registry.py
+++ b/src/plugin_runtime/capabilities/registry.py
@@ -1,6 +1,7 @@
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING
 
 from src.common.logger import get_logger
+from src.plugin_runtime.host.capability_service import CapabilityImpl
 from src.plugin_runtime.host.supervisor import PluginSupervisor
 
 if TYPE_CHECKING:
@@ -12,17 +13,15 @@ logger = get_logger("plugin_runtime.integration")
 def register_capability_impls(manager: "PluginRuntimeManager", supervisor: PluginSupervisor) -> None:
     """向指定 Supervisor 注册主程序提供的能力实现。"""
     cap_service = supervisor.capability_service
-    rpc_server = supervisor.rpc_server
 
-    def _register(name: str, impl: Any) -> None:
-        """注册单个能力实现及其 RPC 入口。
+    def _register(name: str, impl: CapabilityImpl) -> None:
+        """注册单个能力实现。
 
         Args:
             name: 能力名称。
             impl: 能力实现函数。
         """
         cap_service.register_capability(name, impl)
-        rpc_server.register_method(name, cap_service.handle_capability_request)
 
     _register("send.text", manager._cap_send_text)
     _register("send.emoji", manager._cap_send_emoji)
diff --git a/src/plugin_runtime/host/capability_service.py b/src/plugin_runtime/host/capability_service.py
index 761b20ca..0ff31fe1 100644
--- a/src/plugin_runtime/host/capability_service.py
+++ b/src/plugin_runtime/host/capability_service.py
@@ -56,19 +56,14 @@ class CapabilityService:
         校验权限后调用对应实现。
         """
         plugin_id = envelope.plugin_id
-        payload = envelope.payload if isinstance(envelope.payload, dict) else {}
 
         try:
-            req = CapabilityRequestPayload.model_validate(payload)
-            capability = req.capability
-            args = req.args
-        except Exception:
-            capability = envelope.method
-            raw_args = payload.get("args", payload)
-            args = raw_args if isinstance(raw_args, dict) else {}
+            req = CapabilityRequestPayload.model_validate(envelope.payload)
+        except Exception as exc:
+            return envelope.make_error_response(ErrorCode.E_BAD_PAYLOAD.value, f"能力调用 payload 非法: {exc}")
 
-        if not capability:
-            return envelope.make_error_response(ErrorCode.E_BAD_PAYLOAD.value, "能力调用缺少 capability")
+        capability = req.capability
+        args = req.args
 
         # 1. 权限校验
         allowed, reason = self._authorization.check_capability(plugin_id, capability)
diff --git a/src/plugin_runtime/runner/runner_main.py b/src/plugin_runtime/runner/runner_main.py
index 771e685f..bf36a05c 100644
--- a/src/plugin_runtime/runner/runner_main.py
+++ b/src/plugin_runtime/runner/runner_main.py
@@ -237,9 +237,12 @@ class PluginRunner:
                     f"插件 {bound_plugin_id} 尝试以 {plugin_id} 身份发起 RPC，已强制绑定回自身身份"
                 )
             resp = await rpc_client.send_request(
-                method=method,
+                method="cap.call",
                 plugin_id=bound_plugin_id,
-                payload=payload or {},
+                payload={
+                    "capability": method,
+                    "args": payload or {},
+                },
             )
             # 从响应信封中提取业务结果
             if resp.error: