feat(memory): add memory gateway client and service

app-instance/backend/beaver/integrations/memory_gateway/client.py

@@ -0,0 +1,68 @@
+"""Small asynchronous client for the Memory Gateway API."""
+
+from __future__ import annotations
+
+from typing import Any
+
+import httpx
+
+from beaver.foundation.config import MemoryGatewayConfig
+
+
+class MemoryGatewayClientError(RuntimeError):
+    """Sanitized Gateway transport or response failure."""
+
+    def __init__(self, operation: str, category: str, *, status_code: int | None = None) -> None:
+        self.operation = operation
+        self.category = category
+        self.status_code = status_code
+        status = f" status={status_code}" if status_code is not None else ""
+        super().__init__(f"Memory Gateway {operation} failed: {category}{status}")
+
+
+class MemoryGatewayClient:
+    """HTTP transport for search, add, and flush operations."""
+
+    def __init__(
+        self,
+        config: MemoryGatewayConfig,
+        *,
+        transport: httpx.AsyncBaseTransport | None = None,
+    ) -> None:
+        self.config = config
+        self.transport = transport
+
+    async def search(self, payload: dict[str, Any]) -> dict[str, Any]:
+        return await self._post("search", "/memories/search", payload)
+
+    async def add(self, payload: dict[str, Any]) -> dict[str, Any]:
+        return await self._post("add", "/memories/add", payload)
+
+    async def flush(self, payload: dict[str, Any]) -> dict[str, Any]:
+        return await self._post("flush", "/memories/flush", payload)
+
+    async def _post(self, operation: str, path: str, payload: dict[str, Any]) -> dict[str, Any]:
+        try:
+            async with httpx.AsyncClient(
+                base_url=self.config.base_url.rstrip("/"),
+                timeout=self.config.timeout_seconds,
+                transport=self.transport,
+                trust_env=False,
+            ) as client:
+                response = await client.post(path, json=payload)
+                response.raise_for_status()
+                data = response.json()
+        except httpx.HTTPStatusError as exc:
+            raise MemoryGatewayClientError(
+                operation,
+                "http_status",
+                status_code=exc.response.status_code,
+            ) from None
+        except httpx.RequestError:
+            raise MemoryGatewayClientError(operation, "network") from None
+        except ValueError:
+            raise MemoryGatewayClientError(operation, "invalid_json") from None
+
+        if not isinstance(data, dict):
+            raise MemoryGatewayClientError(operation, "invalid_response")
+        return data