fix(mcp-health): deterministic MCP namespace attachment (Closes #689)

session_context_binding.py

@@ -33,6 +33,10 @@ class _SessionContext:
     source: str
     pid: int
     canonical_repository_root: str | None = None
+    cohort_id: str | None = None
+    startup_sha: str | None = None
+    endpoint: str | None = None
+    config_fingerprint: str | None = None
 
     def as_dict(self) -> dict[str, Any]:
         return {
@@ -47,9 +51,14 @@ class _SessionContext:
             "source": self.source,
             "pid": self.pid,
             "canonical_repository_root": self.canonical_repository_root,
+            "cohort_id": self.cohort_id,
+            "startup_sha": self.startup_sha,
+            "endpoint": self.endpoint,
+            "config_fingerprint": self.config_fingerprint,
         }
 
 
+
 # Process-local only — never a shared file (same rationale as mutation authority).
 # The frozen value prevents partial mutation, while the lock makes first-bind and
 # sanctioned rebind atomic across concurrent MCP calls.
@@ -72,6 +81,13 @@ def _reset_session_context_for_testing() -> None:
         _SESSION_CONTEXT = None
 
 
+def clear_session_context() -> None:
+    """Purge process-session context and cohort bindings on disconnect."""
+    global _SESSION_CONTEXT
+    with _SESSION_CONTEXT_LOCK:
+        _SESSION_CONTEXT = None
+
+
 def get_session_context() -> dict[str, Any] | None:
     """Return a detached snapshot of the bound context, or None if unbound."""
     with _SESSION_CONTEXT_LOCK:
@@ -146,6 +162,10 @@ def bind_session_context(
     expected_username: str | None = None,
     source: str = "bind",
     canonical_repository_root: str | None = None,
+    cohort_id: str | None = None,
+    startup_sha: str | None = None,
+    endpoint: str | None = None,
+    config_fingerprint: str | None = None,
 ) -> dict[str, Any]:
     """Atomically bind/re-bind context (the explicit activation path)."""
     with _SESSION_CONTEXT_LOCK:
@@ -160,6 +180,10 @@ def bind_session_context(
             expected_username=expected_username,
             source=source,
             canonical_repository_root=canonical_repository_root,
+            cohort_id=cohort_id,
+            startup_sha=startup_sha,
+            endpoint=endpoint,
+            config_fingerprint=config_fingerprint,
         )
 
 
@@ -175,6 +199,10 @@ def _bind_session_context_unlocked(
     expected_username: str | None,
     source: str,
     canonical_repository_root: str | None = None,
+    cohort_id: str | None = None,
+    startup_sha: str | None = None,
+    endpoint: str | None = None,
+    config_fingerprint: str | None = None,
 ) -> dict[str, Any]:
     """Store a complete immutable context while the caller holds the lock."""
     global _SESSION_CONTEXT
@@ -190,6 +218,10 @@ def _bind_session_context_unlocked(
         source=source,
         pid=os.getpid(),
         canonical_repository_root=(canonical_repository_root or "").strip() or None,
+        cohort_id=(cohort_id or "").strip() or None,
+        startup_sha=(startup_sha or "").strip() or None,
+        endpoint=(endpoint or "").strip() or None,
+        config_fingerprint=(config_fingerprint or "").strip() or None,
     )
     return _SESSION_CONTEXT.as_dict()
 
@@ -206,6 +238,10 @@ def seed_session_context_if_unbound(
     expected_username: str | None = None,
     source: str = "seed",
     canonical_repository_root: str | None = None,
+    cohort_id: str | None = None,
+    startup_sha: str | None = None,
+    endpoint: str | None = None,
+    config_fingerprint: str | None = None,
 ) -> dict[str, Any]:
     """Atomically bind only when this process has no current context.
 
@@ -227,10 +263,15 @@ def seed_session_context_if_unbound(
                 expected_username=expected_username,
                 source=source,
                 canonical_repository_root=canonical_repository_root,
+                cohort_id=cohort_id,
+                startup_sha=startup_sha,
+                endpoint=endpoint,
+                config_fingerprint=config_fingerprint,
             )
         return _SESSION_CONTEXT.as_dict()
 
 
+
 def assess_session_context(
     *,
     profile_name: str | None,
@@ -586,6 +627,10 @@ def mutation_context_audit_fields(
             "session_identity": None,
             "session_repository": None,
             "session_org": None,
+            "session_cohort_id": None,
+            "session_startup_sha": None,
+            "session_endpoint": None,
+            "session_config_fingerprint": None,
         }
     return {
         "session_context_bound": True,
@@ -598,9 +643,14 @@ def mutation_context_audit_fields(
         "session_role_kind": data.get("role_kind"),
         "session_context_source": data.get("source"),
         "session_canonical_repository_root": data.get("canonical_repository_root"),
+        "session_cohort_id": data.get("cohort_id"),
+        "session_startup_sha": data.get("startup_sha"),
+        "session_endpoint": data.get("endpoint"),
+        "session_config_fingerprint": data.get("config_fingerprint"),
     }
 
 
+
 def _assessment(
     proven: bool, reasons: list[str], ctx: Mapping[str, Any] | None
 ) -> dict[str, Any]: