feat(gateway): service-accounts management endpoints (Stage 1 PR4)

Owner/admin self-service CRUD for service accounts: POST create,
GET list, PATCH status; workspace-scoped with 404 existence hiding
for cross-workspace targets. Gated by require_workspace_admin.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/app/gateway/app.py

@@ -22,6 +22,7 @@ from app.gateway.routers import (
     memory,
     models,
     runs,
+    service_accounts,
     skills,
     suggestions,
     thread_runs,
@@ -411,6 +412,9 @@ This gateway provides custom endpoints for models, MCP configuration, skills, an
     # Auth API is mounted at /api/v1/auth
     app.include_router(auth.router)
 
+    # Service Accounts API is mounted at /api/v1/service-accounts
+    app.include_router(service_accounts.router)
+
     # Feedback API is mounted at /api/threads/{thread_id}/runs/{run_id}/feedback
     app.include_router(feedback.router)
 

backend/app/gateway/routers/service_accounts.py

@@ -0,0 +1,76 @@
+"""Service account management endpoints (Stage 1 PR4).
+
+Owner/admin self-service: create / list / suspend service accounts in
+the caller's current workspace. All operations are workspace-scoped;
+cross-workspace targets return 404 (existence hidden).
+"""
+
+from __future__ import annotations
+
+from fastapi import APIRouter, Depends, HTTPException, Request
+from pydantic import BaseModel, Field
+
+from app.gateway.authz import require_workspace_admin
+from deerflow.persistence.service_account import ServiceAccountRepository
+from deerflow.runtime.workspace_context import get_current_workspace
+
+router = APIRouter(prefix="/api/v1/service-accounts", tags=["service-accounts"])
+
+
+class CreateServiceAccountRequest(BaseModel):
+    name: str = Field(..., min_length=1, max_length=64)
+    role: str = Field(default="member")
+    identity_mode: str = Field(default="collapsed")
+
+
+class UpdateServiceAccountRequest(BaseModel):
+    status: str = Field(..., pattern="^(active|suspended|deleted)$")
+
+
+def get_service_account_repo() -> ServiceAccountRepository:
+    from deerflow.persistence.engine import get_session_factory
+
+    sf = get_session_factory()
+    if sf is None:
+        raise HTTPException(status_code=503, detail="persistence backend not available")
+    return ServiceAccountRepository(sf)
+
+
+def _current_workspace_id() -> str:
+    ws = get_current_workspace()
+    if ws is None:
+        raise HTTPException(status_code=403, detail="no workspace in context")
+    return str(ws.id)
+
+
+@router.post("", status_code=201, dependencies=[Depends(require_workspace_admin)])
+async def create_service_account(
+    body: CreateServiceAccountRequest,
+    request: Request,
+    repo: ServiceAccountRepository = Depends(get_service_account_repo),
+):
+    return await repo.create(
+        workspace_id=_current_workspace_id(),
+        name=body.name,
+        created_by=str(request.state.user.id),
+        role=body.role,
+        identity_mode=body.identity_mode,
+    )
+
+
+@router.get("", dependencies=[Depends(require_workspace_admin)])
+async def list_service_accounts(repo: ServiceAccountRepository = Depends(get_service_account_repo)):
+    return await repo.list_by_workspace(_current_workspace_id())
+
+
+@router.patch("/{sa_id}", dependencies=[Depends(require_workspace_admin)])
+async def update_service_account(
+    sa_id: str,
+    body: UpdateServiceAccountRequest,
+    repo: ServiceAccountRepository = Depends(get_service_account_repo),
+):
+    sa = await repo.get(sa_id)
+    if sa is None or sa["workspace_id"] != _current_workspace_id():
+        raise HTTPException(status_code=404, detail="service account not found")
+    await repo.update_status(sa_id, body.status)
+    return await repo.get(sa_id)