From ec1bc5a33c690c33bc1f6ede76da99d2258c646f Mon Sep 17 00:00:00 2001
From: Brian O'Kelley <bokelley@scope3.com>
Date: Tue, 3 Nov 2026 14:17:57 -0500
Subject: [PATCH] fix(reporting): isolate handler registrations for each
 installation

* fix(reporting): allocate a unique handler name for every installation

Give each newly installed reporting handler its own UUID-backed class name.
Service addresses can be reused, and one service can install sellers with
separate advertised tool sets. Preserve same-platform reinstall identity and
strict conflicting handler registration checks.

Fixes #1846

* test(reporting): isolate the installation fixture from global handler names

(cherry picked from commit 86302d09404067410a60d3f9d0f850790038a36f)
---
 src/adcp/reporting/service.py            |  4 +-
 tests/test_reporting_install_identity.py | 64 ++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 tests/test_reporting_install_identity.py

diff --git a/src/adcp/reporting/service.py b/src/adcp/reporting/service.py
index e613f2282c..302ae45326 100644
--- a/src/adcp/reporting/service.py
+++ b/src/adcp/reporting/service.py
@@ -18,6 +18,7 @@
 from datetime import datetime, timedelta, timezone
 from types import MappingProxyType
 from typing import TYPE_CHECKING, Any, Protocol, runtime_checkable
+from uuid import uuid4
 from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
 
 from pydantic import BaseModel
@@ -2086,7 +2087,8 @@ async def delegated(instance: Any, *args: Any, **kwargs: Any) -> Any:
 
             attrs[name] = passthrough(name, method)
 
-        installed_name = f"ReliableReporting{original.__name__}_{id(self):x}"
+        # Registrations outlive services, and one service can install several sellers.
+        installed_name = f"ReliableReporting{original.__name__}_{uuid4().hex}"
         installed = type(
             installed_name,
             (ReportingInstallMixin, original),
diff --git a/tests/test_reporting_install_identity.py b/tests/test_reporting_install_identity.py
new file mode 100644
index 0000000000..073cbc61fc
--- /dev/null
+++ b/tests/test_reporting_install_identity.py
@@ -0,0 +1,64 @@
+"""Reporting installations must retain each seller's own advertised tools."""
+
+from __future__ import annotations
+
+from typing import Any
+
+import pytest
+
+from adcp.reporting.service import ReliableReportingService
+from adcp.server import ADCPHandler
+from adcp.server.mcp_tools import get_tools_for_handler, register_handler_tools
+
+
+# Raw handler names share a process-wide registry with other tests.
+class _InstallationIdentitySeller(ADCPHandler):
+    def __init__(self, tool: str) -> None:
+        super().__init__()
+        self.tool = tool
+
+    def advertised_tools_for_instance(self) -> set[str]:
+        return {self.tool}
+
+    async def get_products(self, params: Any, context: Any = None) -> Any:
+        return {"products": [{"product_id": "first-seller"}]}
+
+    async def get_media_buys(self, params: Any, context: Any = None) -> Any:
+        return {"media_buys": [{"media_buy_id": "second-seller"}]}
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("same_service", [True, False])
+async def test_install_preserves_distinct_seller_surfaces(same_service: bool) -> None:
+    first_service = ReliableReportingService.memory(account_context=lambda *_: None)
+    second_service = (
+        first_service
+        if same_service
+        else ReliableReportingService.memory(account_context=lambda *_: None)
+    )
+    first = first_service.install(_InstallationIdentitySeller("get_products"))
+    first_type = type(first)
+    assert first_service.install(first) is first
+    assert type(first) is first_type
+
+    second = second_service.install(_InstallationIdentitySeller("get_media_buys"))
+    second_type = type(second)
+    assert second_type.__name__ != first_type.__name__
+    assert second_service.install(second) is second
+    assert type(second) is second_type
+
+    first_tools = {item["name"] for item in get_tools_for_handler(first, _include_schemas=False)}
+    second_tools = {item["name"] for item in get_tools_for_handler(second, _include_schemas=False)}
+    assert "get_products" in first_tools and "get_media_buys" not in first_tools
+    assert "get_media_buys" in second_tools and "get_products" not in second_tools
+    assert await first.get_products({}) == {"products": [{"product_id": "first-seller"}]}
+    assert await second.get_media_buys({}) == {"media_buys": [{"media_buy_id": "second-seller"}]}
+
+    # New installation names must not weaken the public registry's conflict guard.
+    registered = first_type.advertised_tools
+    register_handler_tools(first_type.__name__, registered)
+    with pytest.raises(ValueError, match="called twice with different tool sets"):
+        register_handler_tools(first_type.__name__, registered | {"get_media_buys"})
+    assert {
+        item["name"] for item in get_tools_for_handler(first, _include_schemas=False)
+    } == first_tools