feat: add OpenHerbarium MCP server core

src/openherbarium_mcp/http.py

@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+from collections.abc import Mapping
+from typing import Any
+
+import httpx
+
+USER_AGENT = "OpenHerbarium-MCP/0.1 (+https://example.invalid/openherbarium-mcp)"
+
+
+class BotanicalHTTPClient:
+    """Small async HTTP wrapper with conservative defaults for public botanical APIs."""
+
+    def __init__(self, timeout: float = 20.0, transport: httpx.AsyncBaseTransport | None = None):
+        self.timeout = timeout
+        self.transport = transport
+        self._client: httpx.AsyncClient | None = None
+
+    async def __aenter__(self) -> "BotanicalHTTPClient":
+        self._client = httpx.AsyncClient(
+            timeout=self.timeout,
+            follow_redirects=True,
+            transport=self.transport,
+            headers={"User-Agent": USER_AGENT, "Accept": "application/json,text/html;q=0.9,*/*;q=0.8"},
+        )
+        return self
+
+    async def __aexit__(self, exc_type, exc, tb) -> None:  # type: ignore[no-untyped-def]
+        if self._client:
+            await self._client.aclose()
+
+    @property
+    def client(self) -> httpx.AsyncClient:
+        if self._client is None:
+            raise RuntimeError("BotanicalHTTPClient must be used as an async context manager")
+        return self._client
+
+    async def get_json(self, url: str, params: Mapping[str, Any] | None = None) -> dict[str, Any]:
+        response = await self.client.get(url, params=params)
+        response.raise_for_status()
+        data = response.json()
+        return data if isinstance(data, dict) else {"results": data}
+
+    async def post_json(self, url: str, payload: Mapping[str, Any], headers: Mapping[str, str] | None = None) -> dict[str, Any]:
+        response = await self.client.post(url, json=payload, headers=headers)
+        response.raise_for_status()
+        data = response.json()
+        return data if isinstance(data, dict) else {"results": data}