diff --git a/src/github.com/matrix-org/dendrite/federationapi/routing/join.go b/src/github.com/matrix-org/dendrite/federationapi/routing/join.go
new file mode 100644
index 000000000..d06b243b9
--- /dev/null
+++ b/src/github.com/matrix-org/dendrite/federationapi/routing/join.go
@@ -0,0 +1,93 @@
+// Copyright 2017 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package routing
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/matrix-org/dendrite/clientapi/httputil"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/common"
+	"github.com/matrix-org/dendrite/common/config"
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+)
+
+func MakeJoin(
+	ctx context.Context,
+	httpReq *http.Request,
+	request *gomatrixserverlib.FederationRequest,
+	cfg config.Dendrite,
+	query api.RoomserverQueryAPI,
+	now time.Time,
+	keys gomatrixserverlib.KeyRing,
+	roomID, userID string,
+) util.JSONResponse {
+	builder := gomatrixserverlib.EventBuilder{
+		Sender:   userID,
+		RoomID:   roomID,
+		Type:     "m.room.member",
+		StateKey: &userID,
+	}
+	err := builder.SetContent(map[string]interface{}{"membership": "join"})
+	if err != nil {
+		return httputil.LogThenError(httpReq, err)
+	}
+
+	var queryRes api.QueryLatestEventsAndStateResponse
+	event, err := common.BuildEvent(ctx, &builder, cfg, query, &queryRes)
+	if err == common.ErrRoomNoExists {
+		return util.JSONResponse{
+			Code: 404,
+			JSON: jsonerror.NotFound("Room does not exist"),
+		}
+	} else if err != nil {
+		return httputil.LogThenError(httpReq, err)
+	}
+
+	// check to see if this user can perform this operation
+	stateEvents := make([]*gomatrixserverlib.Event, len(queryRes.StateEvents))
+	for i := range queryRes.StateEvents {
+		stateEvents[i] = &queryRes.StateEvents[i]
+	}
+	provider := gomatrixserverlib.NewAuthEvents(stateEvents)
+	if err = gomatrixserverlib.Allowed(*event, &provider); err != nil {
+		return util.JSONResponse{
+			Code: 403,
+			JSON: jsonerror.Forbidden(err.Error()), // TODO: Is this error string comprehensible to the client?
+		}
+	}
+
+	return util.JSONResponse{
+		Code: 200,
+		JSON: event,
+	}
+}
+
+func SendJoin(
+	ctx context.Context,
+	httpReq *http.Request,
+	request *gomatrixserverlib.FederationRequest,
+	cfg config.Dendrite,
+	query api.RoomserverQueryAPI,
+	now time.Time,
+	keys gomatrixserverlib.KeyRing,
+	roomID, eventID string,
+) util.JSONResponse {
+
+}
diff --git a/src/github.com/matrix-org/dendrite/federationapi/routing/routing.go b/src/github.com/matrix-org/dendrite/federationapi/routing/routing.go
index b23d738f9..5d921b3c5 100644
--- a/src/github.com/matrix-org/dendrite/federationapi/routing/routing.go
+++ b/src/github.com/matrix-org/dendrite/federationapi/routing/routing.go
@@ -124,6 +124,18 @@ func Setup(
 		},
 	)).Methods("GET")
 
+	v1fedmux.Handle("/make_join/{roomID}/{userID}", common.MakeFedAPI(
+		"federation_make_join", cfg.Matrix.ServerName, keys,
+		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
+			vars := mux.Vars(httpReq)
+			roomID := vars["roomID"]
+			userID := vars["userID"]
+			return MakeJoin(
+				httpReq.Context(), httpReq, request, cfg, query, time.Now(), keys, roomID, userID,
+			)
+		},
+	)).Methods("GET")
+
 	v1fedmux.Handle("/version", common.MakeExternalAPI(
 		"federation_version",
 		func(httpReq *http.Request) util.JSONResponse {