1 files changed, 68 insertions, 0 deletions
diff --git a/packages/meshbay-node/src/meshbay_node/ui/app.py b/packages/meshbay-node/src/meshbay_node/ui/app.py
index 28654df..b78f78d 100644
--- a/packages/meshbay-node/src/meshbay_node/ui/app.py
+++ b/packages/meshbay-node/src/meshbay_node/ui/app.py
@@ -23,6 +23,7 @@ from fastapi import FastAPI, WebSocket, WebSocketDisconnect, Query
 from fastapi.responses import HTMLResponse, JSONResponse
 
 from meshbay_node import __version__
+from meshbay_node.config import DEFAULT_CONFIG_PATH
 from meshbay_common.crypto import generate_gek, wrap_gek_aes
 from meshbay_common.join import ROLE_MEMBER, ROLE_OPERATOR
 
@@ -127,6 +128,73 @@ def create_ui_app(state: dict) -> FastAPI:
             })
         return {"groups": result}
 
+    @app.post("/api/groups/attach")
+    async def attach_group(payload: dict):
+        """
+        Write a new [[groups]] block into node.toml.
+
+        The name-to-id lookup happens here because this process is the one logged
+        into the hub. Nothing is created on the hub: the group already exists,
+        this only tells the node to host it.
+        """
+        name = (payload.get("name") or "").strip()
+        shared_dir = (payload.get("shared_dir") or "").strip()
+        if not name or not shared_dir:
+            return JSONResponse({"error": "name and shared_dir are required"}, 400)
+
+        config = state.get("config")
+        if not config:
+            return JSONResponse({"error": "No config loaded"}, 503)
+
+        hub = state.get("hub")
+        if not hub or not hub._session:
+            return JSONResponse({"error": "Hub not connected"}, 503)
+        try:
+            mine = await hub.list_my_groups()
+        except Exception as e:
+            return JSONResponse({"error": f"Could not list groups: {e}"}, 502)
+
+        match = [g for g in mine if g["id"] == name or g["name"] == name]
+        if not match:
+            return JSONResponse({
+                "error": f"No group of yours is called {name!r}",
+                "available": [{"name": g["name"], "id": g["id"]} for g in mine],
+            }, 404)
+        if len(match) > 1:
+            return JSONResponse({
+                "error": f"Several of your groups are called {name!r} — use the id",
+                "available": [{"name": g["name"], "id": g["id"]} for g in match],
+            }, 409)
+        group = match[0]
+
+        if any(g.id == group["id"] for g in config.groups):
+            return JSONResponse(
+                {"error": f"{group['name']!r} is already hosted by this node"}, 409)
+
+        path = Path(shared_dir).expanduser()
+        try:
+            path.mkdir(parents=True, exist_ok=True)
+        except OSError as e:
+            return JSONResponse({"error": f"Cannot create {path}: {e}"}, 400)
+
+        # Appended as text rather than re-serialised: node.toml is hand-written
+        # and full of comments explaining decisions, and a round trip through a
+        # TOML writer would throw all of that away.
+        conf_path = Path(state.get("config_path") or DEFAULT_CONFIG_PATH)
+        block = (f'\n[[groups]]\n'
+                 f'id          = "{group["id"]}"\n'
+                 f'name        = "{group["name"]}"\n'
+                 f'shared_dir  = "{path}"\n'
+                 f'visibility  = "{group.get("visibility", "private")}"\n')
+        try:
+            with conf_path.open("a") as f:
+                f.write(block)
+        except OSError as e:
+            return JSONResponse({"error": f"Cannot write {conf_path}: {e}"}, 500)
+
+        return {"group_id": group["id"], "name": group["name"],
+                "shared_dir": str(path), "config": str(conf_path)}
+
     @app.get("/api/groups/{group_id}/files")
     async def api_group_files(group_id: str):
         groups_ctx = state.get("groups_ctx", {})