diff --git a/docs/MODULE_ARCHITECTURE.md b/docs/MODULE_ARCHITECTURE.md
index 9ce6ee1..a21b6de 100644
--- a/docs/MODULE_ARCHITECTURE.md
+++ b/docs/MODULE_ARCHITECTURE.md
@@ -208,7 +208,8 @@ Other stable runtime capabilities currently include:
 - `identity.directory` and `identity.search`
 - `organizations.directory`
 - `idm.directory`
-- `calendar.outbox` and `calendar.scheduling`
+- `calendar.outbox`, `calendar.scheduling`, `calendar.invitations`, and
+  `calendar.externalProfiles`
 - `poll.scheduling`
 - `notifications.dispatch`
 - `workflow.definitionContributions` and `workflow.runtimeWorker`
@@ -286,7 +287,8 @@ Current named interfaces, generated from the source manifests by the workspace
 contract checks, are:
 
 - `addresses.contact_writer`, `addresses.lookup`, `addresses.recipient_source`
-- `calendar.outbox`, `calendar.scheduling`
+- `calendar.external_profiles`, `calendar.invitations`, `calendar.outbox`,
+  `calendar.scheduling`
 - `campaigns.access`, `campaigns.delivery_tasks`,
   `campaigns.mail_policy_context`, `campaigns.policy_context`,
   `campaigns.retention`
diff --git a/src/govoplan_core/core/calendar.py b/src/govoplan_core/core/calendar.py
index 5d88544..045673d 100644
--- a/src/govoplan_core/core/calendar.py
+++ b/src/govoplan_core/core/calendar.py
@@ -9,6 +9,7 @@ from typing import Protocol, runtime_checkable
 CAPABILITY_CALENDAR_SCHEDULING = "calendar.scheduling"
 CAPABILITY_CALENDAR_OUTBOX = "calendar.outbox"
 CAPABILITY_CALENDAR_INVITATIONS = "calendar.invitations"
+CAPABILITY_CALENDAR_EXTERNAL_PROFILES = "calendar.externalProfiles"
 CALENDAR_AVAILABILITY_READ_SCOPE = "calendar:availability:read"
 CALENDAR_EVENT_WRITE_SCOPE = "calendar:event:write"
 
@@ -90,6 +91,38 @@ class CalendarInvitationRef:
     degraded_reasons: tuple[str, ...] = ()
 
 
+@dataclass(frozen=True, slots=True)
+class CalendarExternalProfileRequest:
+    """Connector-neutral request for a Calendar-owned external profile."""
+
+    profile_kind: str
+    calendar_id: str
+    endpoint_url: str
+    display_name: str | None = None
+    auth_type: str = "none"
+    username: str | None = None
+    credential_ref: str | None = None
+    sync_enabled: bool = True
+    sync_interval_seconds: int = 900
+    sync_direction: str = "two_way"
+    conflict_policy: str = "etag"
+    connector_profile_ref: str | None = None
+    identity_mapping_ref: str | None = None
+    resource_calendar_ref: str | None = None
+    metadata: Mapping[str, object] = field(default_factory=dict)
+
+
+@dataclass(frozen=True, slots=True)
+class CalendarExternalProfileRef:
+    source_id: str
+    calendar_id: str
+    profile_kind: str
+    transport_kind: str
+    connector_profile_ref: str | None = None
+    identity_mapping_ref: str | None = None
+    resource_calendar_ref: str | None = None
+
+
 @runtime_checkable
 class CalendarSchedulingProvider(Protocol):
     def list_freebusy(
@@ -165,6 +198,25 @@ class CalendarInvitationProvider(Protocol):
     ) -> CalendarInvitationRef:
         ...
 
+
+@runtime_checkable
+class CalendarExternalProfileProvider(Protocol):
+    """Optional connector route for Calendar-owned groupware adapters."""
+
+    def supported_profiles(self) -> Sequence[Mapping[str, object]]:
+        ...
+
+    def configure_profile(
+        self,
+        session: object,
+        *,
+        tenant_id: str,
+        user_id: str | None,
+        request: CalendarExternalProfileRequest,
+    ) -> CalendarExternalProfileRef:
+        ...
+
+
 def calendar_scheduling_provider(registry: object | None) -> CalendarSchedulingProvider | None:
     if registry is None or not hasattr(registry, "has_capability"):
         return None
@@ -192,3 +244,18 @@ def calendar_invitation_provider(
         return None
     capability = registry.capability(CAPABILITY_CALENDAR_INVITATIONS)
     return capability if isinstance(capability, CalendarInvitationProvider) else None
+
+
+def calendar_external_profile_provider(
+    registry: object | None,
+) -> CalendarExternalProfileProvider | None:
+    if registry is None or not hasattr(registry, "has_capability"):
+        return None
+    if not registry.has_capability(CAPABILITY_CALENDAR_EXTERNAL_PROFILES):
+        return None
+    capability = registry.capability(CAPABILITY_CALENDAR_EXTERNAL_PROFILES)
+    return (
+        capability
+        if isinstance(capability, CalendarExternalProfileProvider)
+        else None
+    )