feat(cerbero): HTTP client with bearer + bot-tag + retry

Client minimale verso Cerbero MCP unified server con header
Authorization Bearer e X-Bot-Tag su ogni richiesta. Retry esponenziale
solo su ConnectionError (non su 4xx). 4xx/5xx -> RuntimeError.

Switch da httpx a requests per allineamento con libreria mock
`responses` (httpx richiederebbe respx). httpx resta in deps per usi
futuri. Aggiunto types-requests ai dev deps per mypy strict.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pyproject.toml

@@ -16,6 +16,7 @@ dependencies = [
     "anthropic>=0.39",
     "openai>=1.55",
     "httpx>=0.28",
+    "requests>=2.32",
     "tenacity>=9.0",
     "pyyaml>=6.0",
     "streamlit>=1.40",
@@ -31,6 +32,7 @@ dev = [
     "responses>=0.25",
     "ruff>=0.7",
     "mypy>=1.13",
+    "types-requests>=2.32",
 ]
 
 [build-system]

src/multi_swarm/cerbero/client.py

@@ -0,0 +1,60 @@
+from __future__ import annotations
+
+from types import TracebackType
+from typing import Any
+
+import requests
+from tenacity import retry, retry_if_exception_type, stop_after_attempt, wait_exponential
+
+
+class CerberoClient:
+    """Client HTTP minimale verso Cerbero MCP unified server."""
+
+    def __init__(
+        self,
+        base_url: str,
+        token: str,
+        bot_tag: str,
+        timeout_seconds: float = 10.0,
+    ) -> None:
+        self.base_url = base_url.rstrip("/")
+        self.token = token
+        self.bot_tag = bot_tag
+        self.timeout_seconds = timeout_seconds
+        self._session = requests.Session()
+        self._session.headers.update(
+            {
+                "Authorization": f"Bearer {token}",
+                "X-Bot-Tag": bot_tag,
+                "Content-Type": "application/json",
+            }
+        )
+
+    def close(self) -> None:
+        self._session.close()
+
+    def __enter__(self) -> CerberoClient:
+        return self
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> None:
+        self.close()
+
+    @retry(
+        stop=stop_after_attempt(3),
+        wait=wait_exponential(multiplier=0.5, min=0.5, max=4.0),
+        retry=retry_if_exception_type(requests.ConnectionError),
+        reraise=True,
+    )
+    def call_tool(self, exchange: str, tool: str, args: dict[str, Any]) -> Any:
+        url = f"{self.base_url}/mcp-{exchange}/tools/{tool}"
+        resp = self._session.post(url, json=args, timeout=self.timeout_seconds)
+        if resp.status_code >= 400:
+            raise RuntimeError(
+                f"Cerbero {exchange}/{tool} returned {resp.status_code}: {resp.text}"
+            )
+        return resp.json()

tests/unit/test_cerbero_client.py

@@ -0,0 +1,37 @@
+import pytest
+import responses
+
+from multi_swarm.cerbero.client import CerberoClient
+
+
+@responses.activate
+def test_call_tool_passes_bearer_and_bot_tag() -> None:
+    responses.add(
+        responses.POST,
+        "http://test:9000/mcp-deribit/tools/get_iv_rank",
+        json={"iv_rank": 0.42},
+        status=200,
+    )
+    client = CerberoClient(
+        base_url="http://test:9000", token="tok-xyz", bot_tag="swarm-poc-phase1"
+    )
+    result = client.call_tool("deribit", "get_iv_rank", {"symbol": "BTC-PERPETUAL"})
+    assert result == {"iv_rank": 0.42}
+    req = responses.calls[0].request
+    assert req.headers["Authorization"] == "Bearer tok-xyz"
+    assert req.headers["X-Bot-Tag"] == "swarm-poc-phase1"
+
+
+@responses.activate
+def test_call_tool_raises_on_error() -> None:
+    responses.add(
+        responses.POST,
+        "http://test:9000/mcp-deribit/tools/get_iv_rank",
+        json={"error": "bad"},
+        status=400,
+    )
+    client = CerberoClient(
+        base_url="http://test:9000", token="tok-xyz", bot_tag="swarm-poc-phase1"
+    )
+    with pytest.raises(RuntimeError):
+        client.call_tool("deribit", "get_iv_rank", {})

uv.lock

@@ -898,6 +898,7 @@ dependencies = [
     { name = "pydantic" },
     { name = "pydantic-settings" },
     { name = "pyyaml" },
+    { name = "requests" },
     { name = "scipy" },
     { name = "sexpdata" },
     { name = "sqlmodel" },
@@ -913,6 +914,7 @@ dev = [
     { name = "pytest-mock" },
     { name = "responses" },
     { name = "ruff" },
+    { name = "types-requests" },
 ]
 
 [package.metadata]
@@ -928,6 +930,7 @@ requires-dist = [
     { name = "pydantic", specifier = ">=2.9" },
     { name = "pydantic-settings", specifier = ">=2.6" },
     { name = "pyyaml", specifier = ">=6.0" },
+    { name = "requests", specifier = ">=2.32" },
     { name = "scipy", specifier = ">=1.14" },
     { name = "sexpdata", specifier = ">=1.0.2" },
     { name = "sqlmodel", specifier = ">=0.0.22" },
@@ -943,6 +946,7 @@ dev = [
     { name = "pytest-mock", specifier = ">=3.14" },
     { name = "responses", specifier = ">=0.25" },
     { name = "ruff", specifier = ">=0.7" },
+    { name = "types-requests", specifier = ">=2.32" },
 ]
 
 [[package]]
@@ -2048,6 +2052,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/16/e1/3079a9ff9b8e11b846c6ac5c8b5bfb7ff225eee721825310c91b3b50304f/tqdm-4.67.3-py3-none-any.whl", hash = "sha256:ee1e4c0e59148062281c49d80b25b67771a127c85fc9676d3be5f243206826bf", size = 78374, upload-time = "2026-02-03T17:35:50.982Z" },
 ]
 
+[[package]]
+name = "types-requests"
+version = "2.33.0.20260508"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "urllib3" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/c7/6b/eb226bdd61a982c9a03e02c657fb4ab001733506e6423906ac142331f2e3/types_requests-2.33.0.20260508.tar.gz", hash = "sha256:81b2ae5f0d20967714a6aa5ef9284c05570d7cb06b7de8f2a77b918b63ddd411", size = 23991, upload-time = "2026-05-08T04:50:56.818Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/cb/96/080db0afdf2c5cc5fe512b41354e8d114fe8f65e9510c56ff8dfd40216ce/types_requests-2.33.0.20260508-py3-none-any.whl", hash = "sha256:fa01459cca184229713df03709db46a905325906d27e042cd4fd7ea3d15d3400", size = 20722, upload-time = "2026-05-08T04:50:55.548Z" },
+]
+
 [[package]]
 name = "typing-extensions"
 version = "4.15.0"