Merge branch 'master' into v0.1.0

59 files changed, 470 insertions, 384 deletions

diff --git a/build/docker/config/dendrite-config.yaml b/build/docker/config/dendrite-config.yaml
index 2bf8dd85..2dc2f3b7 100644
--- a/build/docker/config/dendrite-config.yaml
+++ b/build/docker/config/dendrite-config.yaml
@@ -253,12 +253,12 @@ room_server:
     conn_max_lifetime: -1
 
 # Configuration for the Server Key API (for server signing keys).
-server_key_api:
+signing_key_server:
   internal_api:
     listen: http://0.0.0.0:7780
-    connect: http://server_key_api:7780
+    connect: http://signing_key_server:7780
   database:
-    connection_string: postgresql://dendrite:itsasecret@postgres/dendrite_serverkey?sslmode=disable
+    connection_string: postgresql://dendrite:itsasecret@postgres/dendrite_signingkeyserver?sslmode=disable
     max_open_conns: 100
     max_idle_conns: 2
     conn_max_lifetime: -1
diff --git a/build/docker/docker-compose.polylith.yml b/build/docker/docker-compose.polylith.yml
index 6dd74314..8a4c50e0 100644
--- a/build/docker/docker-compose.polylith.yml
+++ b/build/docker/docker-compose.polylith.yml
@@ -128,9 +128,9 @@ services:
     networks:
         - internal
 
-  server_key_api:
-    hostname: server_key_api
-    image: matrixdotorg/dendrite:serverkeyapi
+  signing_key_server:
+    hostname: signing_key_server
+    image: matrixdotorg/dendrite:signingkeyserver
     command: [
       "--config=dendrite.yaml"
     ]
diff --git a/build/docker/images-build.sh b/build/docker/images-build.sh
index fdff5132..d72bac21 100755
--- a/build/docker/images-build.sh
+++ b/build/docker/images-build.sh
@@ -17,5 +17,5 @@ docker build -t matrixdotorg/dendrite:keyserver         --build-arg component=de
 docker build -t matrixdotorg/dendrite:mediaapi          --build-arg component=dendrite-media-api-server         -f build/docker/Dockerfile.component .
 docker build -t matrixdotorg/dendrite:roomserver        --build-arg component=dendrite-room-server              -f build/docker/Dockerfile.component .
 docker build -t matrixdotorg/dendrite:syncapi           --build-arg component=dendrite-sync-api-server          -f build/docker/Dockerfile.component .
-docker build -t matrixdotorg/dendrite:serverkeyapi      --build-arg component=dendrite-server-key-api-server    -f build/docker/Dockerfile.component .
+docker build -t matrixdotorg/dendrite:signingkeyserver      --build-arg component=dendrite-signing-key-server    -f build/docker/Dockerfile.component .
 docker build -t matrixdotorg/dendrite:userapi           --build-arg component=dendrite-user-api-server          -f build/docker/Dockerfile.component .
diff --git a/build/docker/images-pull.sh b/build/docker/images-pull.sh
index c6b09b6a..be918546 100755
--- a/build/docker/images-pull.sh
+++ b/build/docker/images-pull.sh
@@ -13,4 +13,5 @@ docker pull matrixdotorg/dendrite:keyserver
 docker pull matrixdotorg/dendrite:mediaapi
 docker pull matrixdotorg/dendrite:roomserver
 docker pull matrixdotorg/dendrite:syncapi
+docker pull matrixdotorg/dendrite:signingkeyserver
 docker pull matrixdotorg/dendrite:userapi
diff --git a/build/docker/images-push.sh b/build/docker/images-push.sh
index 4838c76f..64920171 100755
--- a/build/docker/images-push.sh
+++ b/build/docker/images-push.sh
@@ -13,5 +13,5 @@ docker push matrixdotorg/dendrite:keyserver
 docker push matrixdotorg/dendrite:mediaapi
 docker push matrixdotorg/dendrite:roomserver
 docker push matrixdotorg/dendrite:syncapi
-docker push matrixdotorg/dendrite:serverkeyapi
+docker push matrixdotorg/dendrite:signingkeyserver
 docker push matrixdotorg/dendrite:userapi
diff --git a/build/docker/postgres/create_db.sh b/build/docker/postgres/create_db.sh
index 70d6743e..f8ee715a 100644
--- a/build/docker/postgres/create_db.sh
+++ b/build/docker/postgres/create_db.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
 
-for db in account device mediaapi syncapi roomserver serverkey keyserver federationsender appservice e2ekey naffka; do
+for db in account device mediaapi syncapi roomserver signingkeyserver keyserver federationsender appservice e2ekey naffka; do
     createdb -U dendrite -O dendrite dendrite_$db
 done
diff --git a/build/gobind/monolith.go b/build/gobind/monolith.go
index b4740ed4..7d10b87e 100644
--- a/build/gobind/monolith.go
+++ b/build/gobind/monolith.go
@@ -94,7 +94,7 @@ func (m *DendriteMonolith) Start() {
 	cfg.MediaAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-mediaapi.db", m.StorageDirectory))
 	cfg.SyncAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-syncapi.db", m.StorageDirectory))
 	cfg.RoomServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-roomserver.db", m.StorageDirectory))
-	cfg.ServerKeyAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-serverkey.db", m.StorageDirectory))
+	cfg.SigningKeyServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-signingkeyserver.db", m.StorageDirectory))
 	cfg.KeyServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-keyserver.db", m.StorageDirectory))
 	cfg.FederationSender.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-federationsender.db", m.StorageDirectory))
 	cfg.AppServiceAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s/dendrite-p2p-appservice.db", m.StorageDirectory))
diff --git a/clientapi/routing/joinroom.go b/clientapi/routing/joinroom.go
index c1011357..578aaec5 100644
--- a/clientapi/routing/joinroom.go
+++ b/clientapi/routing/joinroom.go
@@ -16,9 +16,11 @@ package routing
 
 import (
 	"net/http"
+	"time"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
 	"github.com/matrix-org/dendrite/clientapi/httputil"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
@@ -74,16 +76,32 @@ func JoinRoomByIDOrAlias(
 	}
 
 	// Ask the roomserver to perform the join.
-	rsAPI.PerformJoin(req.Context(), &joinReq, &joinRes)
-	if joinRes.Error != nil {
-		return joinRes.Error.JSONResponse()
-	}
+	done := make(chan util.JSONResponse, 1)
+	go func() {
+		defer close(done)
+		rsAPI.PerformJoin(req.Context(), &joinReq, &joinRes)
+		if joinRes.Error != nil {
+			done <- joinRes.Error.JSONResponse()
+		} else {
+			done <- util.JSONResponse{
+				Code: http.StatusOK,
+				// TODO: Put the response struct somewhere internal.
+				JSON: struct {
+					RoomID string `json:"room_id"`
+				}{joinRes.RoomID},
+			}
+		}
+	}()
 
-	return util.JSONResponse{
-		Code: http.StatusOK,
-		// TODO: Put the response struct somewhere internal.
-		JSON: struct {
-			RoomID string `json:"room_id"`
-		}{joinRes.RoomID},
+	// Wait either for the join to finish, or for us to hit a reasonable
+	// timeout, at which point we'll just return a 200 to placate clients.
+	select {
+	case <-time.After(time.Second * 20):
+		return util.JSONResponse{
+			Code: http.StatusAccepted,
+			JSON: jsonerror.Unknown("The room join will continue in the background."),
+		}
+	case result := <-done:
+		return result
 	}
 }
diff --git a/cmd/dendrite-appservice-server/main.go b/cmd/dendrite-appservice-server/main.go
index 72b243e2..6adbdb17 100644
--- a/cmd/dendrite-appservice-server/main.go
+++ b/cmd/dendrite-appservice-server/main.go
@@ -31,8 +31,8 @@ func main() {
 	appservice.AddInternalRoutes(base.InternalAPIMux, intAPI)
 
 	base.SetupAndServeHTTP(
-		base.Cfg.AppServiceAPI.InternalAPI.Listen,
-		setup.NoExternalListener,
+		base.Cfg.AppServiceAPI.InternalAPI.Listen, // internal listener
+		setup.NoListener, // external listener
 		nil, nil,
 	)
 }
diff --git a/cmd/dendrite-demo-libp2p/main.go b/cmd/dendrite-demo-libp2p/main.go
index 1f674886..0f30e8d3 100644
--- a/cmd/dendrite-demo-libp2p/main.go
+++ b/cmd/dendrite-demo-libp2p/main.go
@@ -36,7 +36,7 @@ import (
 	"github.com/matrix-org/dendrite/internal/setup"
 	"github.com/matrix-org/dendrite/keyserver"
 	"github.com/matrix-org/dendrite/roomserver"
-	"github.com/matrix-org/dendrite/serverkeyapi"
+	"github.com/matrix-org/dendrite/signingkeyserver"
 	"github.com/matrix-org/dendrite/userapi"
 	"github.com/matrix-org/gomatrixserverlib"
 
@@ -125,7 +125,7 @@ func main() {
 	cfg.MediaAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-mediaapi.db", *instanceName))
 	cfg.SyncAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-syncapi.db", *instanceName))
 	cfg.RoomServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-roomserver.db", *instanceName))
-	cfg.ServerKeyAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-serverkey.db", *instanceName))
+	cfg.SigningKeyServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-signingkeyserver.db", *instanceName))
 	cfg.FederationSender.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-federationsender.db", *instanceName))
 	cfg.AppServiceAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-appservice.db", *instanceName))
 	cfg.Global.Kafka.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-naffka.db", *instanceName))
@@ -143,8 +143,8 @@ func main() {
 	userAPI := userapi.NewInternalAPI(accountDB, &cfg.UserAPI, nil, keyAPI)
 	keyAPI.SetUserAPI(userAPI)
 
-	serverKeyAPI := serverkeyapi.NewInternalAPI(
-		&base.Base.Cfg.ServerKeyAPI, federation, base.Base.Caches,
+	serverKeyAPI := signingkeyserver.NewInternalAPI(
+		&base.Base.Cfg.SigningKeyServer, federation, base.Base.Caches,
 	)
 	keyRing := serverKeyAPI.KeyRing()
 	createKeyDB(
diff --git a/cmd/dendrite-demo-yggdrasil/main.go b/cmd/dendrite-demo-yggdrasil/main.go
index 257ddb58..5e8b9231 100644
--- a/cmd/dendrite-demo-yggdrasil/main.go
+++ b/cmd/dendrite-demo-yggdrasil/main.go
@@ -78,7 +78,7 @@ func main() {
 	cfg.MediaAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-mediaapi.db", *instanceName))
 	cfg.SyncAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-syncapi.db", *instanceName))
 	cfg.RoomServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-roomserver.db", *instanceName))
-	cfg.ServerKeyAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-serverkey.db", *instanceName))
+	cfg.SigningKeyServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-signingkeyserver.db", *instanceName))
 	cfg.KeyServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-keyserver.db", *instanceName))
 	cfg.FederationSender.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-federationsender.db", *instanceName))
 	cfg.AppServiceAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-appservice.db", *instanceName))
diff --git a/cmd/dendrite-demo-yggdrasil/yggconn/node.go b/cmd/dendrite-demo-yggdrasil/yggconn/node.go
index 9b123aa6..c036c0d8 100644
--- a/cmd/dendrite-demo-yggdrasil/yggconn/node.go
+++ b/cmd/dendrite-demo-yggdrasil/yggconn/node.go
@@ -205,13 +205,11 @@ func (n *Node) SessionCount() int {
 
 func (n *Node) KnownNodes() []gomatrixserverlib.ServerName {
 	nodemap := map[string]struct{}{
-		"b5ae50589e50991dd9dd7d59c5c5f7a4521e8da5b603b7f57076272abc58b374": {},
+		//"b5ae50589e50991dd9dd7d59c5c5f7a4521e8da5b603b7f57076272abc58b374": {},
+	}
+	for _, peer := range n.core.GetSwitchPeers() {
+		nodemap[hex.EncodeToString(peer.SigPublicKey[:])] = struct{}{}
 	}
-	/*
-		for _, peer := range n.core.GetSwitchPeers() {
-			nodemap[hex.EncodeToString(peer.PublicKey[:])] = struct{}{}
-		}
-	*/
 	n.sessions.Range(func(_, v interface{}) bool {
 		session, ok := v.(quic.Session)
 		if !ok {
diff --git a/cmd/dendrite-edu-server/main.go b/cmd/dendrite-edu-server/main.go
index e0956619..3a34b9a6 100644
--- a/cmd/dendrite-edu-server/main.go
+++ b/cmd/dendrite-edu-server/main.go
@@ -34,8 +34,8 @@ func main() {
 	eduserver.AddInternalRoutes(base.InternalAPIMux, intAPI)
 
 	base.SetupAndServeHTTP(
-		base.Cfg.EDUServer.InternalAPI.Listen,
-		setup.NoExternalListener,
+		base.Cfg.EDUServer.InternalAPI.Listen, // internal listener
+		setup.NoListener,                      // external listener
 		nil, nil,
 	)
 }
diff --git a/cmd/dendrite-federation-api-server/main.go b/cmd/dendrite-federation-api-server/main.go
index cab304e6..3ebb16f4 100644
--- a/cmd/dendrite-federation-api-server/main.go
+++ b/cmd/dendrite-federation-api-server/main.go
@@ -26,7 +26,7 @@ func main() {
 
 	userAPI := base.UserAPIClient()
 	federation := base.CreateFederationClient()
-	serverKeyAPI := base.ServerKeyAPIClient()
+	serverKeyAPI := base.SigningKeyServerHTTPClient()
 	keyRing := serverKeyAPI.KeyRing()
 	fsAPI := base.FederationSenderHTTPClient()
 	rsAPI := base.RoomserverHTTPClient()
diff --git a/cmd/dendrite-federation-sender-server/main.go b/cmd/dendrite-federation-sender-server/main.go
index 4d918f6b..99b416c4 100644
--- a/cmd/dendrite-federation-sender-server/main.go
+++ b/cmd/dendrite-federation-sender-server/main.go
@@ -26,7 +26,7 @@ func main() {
 
 	federation := base.CreateFederationClient()
 
-	serverKeyAPI := base.ServerKeyAPIClient()
+	serverKeyAPI := base.SigningKeyServerHTTPClient()
 	keyRing := serverKeyAPI.KeyRing()
 
 	rsAPI := base.RoomserverHTTPClient()
@@ -36,8 +36,8 @@ func main() {
 	federationsender.AddInternalRoutes(base.InternalAPIMux, fsAPI)
 
 	base.SetupAndServeHTTP(
-		base.Cfg.FederationSender.InternalAPI.Listen,
-		setup.NoExternalListener,
+		base.Cfg.FederationSender.InternalAPI.Listen, // internal listener
+		setup.NoListener, // external listener
 		nil, nil,
 	)
 }
diff --git a/cmd/dendrite-key-server/main.go b/cmd/dendrite-key-server/main.go
index 2110b216..92d18ac3 100644
--- a/cmd/dendrite-key-server/main.go
+++ b/cmd/dendrite-key-server/main.go
@@ -30,8 +30,8 @@ func main() {
 	keyserver.AddInternalRoutes(base.InternalAPIMux, intAPI)
 
 	base.SetupAndServeHTTP(
-		base.Cfg.KeyServer.InternalAPI.Listen,
-		setup.NoExternalListener,
+		base.Cfg.KeyServer.InternalAPI.Listen, // internal listener
+		setup.NoListener,                      // external listener
 		nil, nil,
 	)
 }
diff --git a/cmd/dendrite-monolith-server/main.go b/cmd/dendrite-monolith-server/main.go
index 28a349a7..0fe70ca8 100644
--- a/cmd/dendrite-monolith-server/main.go
+++ b/cmd/dendrite-monolith-server/main.go
@@ -27,13 +27,15 @@ import (
 	"github.com/matrix-org/dendrite/keyserver"
 	"github.com/matrix-org/dendrite/roomserver"
 	"github.com/matrix-org/dendrite/roomserver/api"
-	"github.com/matrix-org/dendrite/serverkeyapi"
+	"github.com/matrix-org/dendrite/signingkeyserver"
 	"github.com/matrix-org/dendrite/userapi"
+	"github.com/sirupsen/logrus"
 )
 
 var (
 	httpBindAddr   = flag.String("http-bind-address", ":8008", "The HTTP listening port for the server")
 	httpsBindAddr  = flag.String("https-bind-address", ":8448", "The HTTPS listening port for the server")
+	apiBindAddr    = flag.String("api-bind-address", "localhost:18008", "The HTTP listening port for the internal HTTP APIs (if -api is enabled)")
 	certFile       = flag.String("tls-cert", "", "The PEM formatted X509 certificate to use for TLS")
 	keyFile        = flag.String("tls-key", "", "The PEM private key to use for TLS")
 	enableHTTPAPIs = flag.Bool("api", false, "Use HTTP APIs instead of short-circuiting (warning: exposes API endpoints!)")
@@ -44,22 +46,25 @@ func main() {
 	cfg := setup.ParseFlags(true)
 	httpAddr := config.HTTPAddress("http://" + *httpBindAddr)
 	httpsAddr := config.HTTPAddress("https://" + *httpsBindAddr)
+	httpAPIAddr := httpAddr
 
 	if *enableHTTPAPIs {
+		logrus.Warnf("DANGER! The -api option is enabled, exposing internal APIs on %q!", *apiBindAddr)
+		httpAPIAddr = config.HTTPAddress("http://" + *apiBindAddr)
 		// If the HTTP APIs are enabled then we need to update the Listen
 		// statements in the configuration so that we know where to find
 		// the API endpoints. They'll listen on the same port as the monolith
 		// itself.
-		cfg.AppServiceAPI.InternalAPI.Connect = httpAddr
-		cfg.ClientAPI.InternalAPI.Connect = httpAddr
-		cfg.EDUServer.InternalAPI.Connect = httpAddr
-		cfg.FederationAPI.InternalAPI.Connect = httpAddr
-		cfg.FederationSender.InternalAPI.Connect = httpAddr
-		cfg.KeyServer.InternalAPI.Connect = httpAddr
-		cfg.MediaAPI.InternalAPI.Connect = httpAddr
-		cfg.RoomServer.InternalAPI.Connect = httpAddr
-		cfg.ServerKeyAPI.InternalAPI.Connect = httpAddr
-		cfg.SyncAPI.InternalAPI.Connect = httpAddr
+		cfg.AppServiceAPI.InternalAPI.Connect = httpAPIAddr
+		cfg.ClientAPI.InternalAPI.Connect = httpAPIAddr
+		cfg.EDUServer.InternalAPI.Connect = httpAPIAddr
+		cfg.FederationAPI.InternalAPI.Connect = httpAPIAddr
+		cfg.FederationSender.InternalAPI.Connect = httpAPIAddr
+		cfg.KeyServer.InternalAPI.Connect = httpAPIAddr
+		cfg.MediaAPI.InternalAPI.Connect = httpAPIAddr
+		cfg.RoomServer.InternalAPI.Connect = httpAPIAddr
+		cfg.SigningKeyServer.InternalAPI.Connect = httpAPIAddr
+		cfg.SyncAPI.InternalAPI.Connect = httpAPIAddr
 	}
 
 	base := setup.NewBaseDendrite(cfg, "Monolith", *enableHTTPAPIs)
@@ -68,14 +73,14 @@ func main() {
 	accountDB := base.CreateAccountsDB()
 	federation := base.CreateFederationClient()
 
-	serverKeyAPI := serverkeyapi.NewInternalAPI(
-		&base.Cfg.ServerKeyAPI, federation, base.Caches,
+	skAPI := signingkeyserver.NewInternalAPI(
+		&base.Cfg.SigningKeyServer, federation, base.Caches,
 	)
 	if base.UseHTTPAPIs {
-		serverkeyapi.AddInternalRoutes(base.InternalAPIMux, serverKeyAPI, base.Caches)
-		serverKeyAPI = base.ServerKeyAPIClient()
+		signingkeyserver.AddInternalRoutes(base.InternalAPIMux, skAPI, base.Caches)
+		skAPI = base.SigningKeyServerHTTPClient()
 	}
-	keyRing := serverKeyAPI.KeyRing()
+	keyRing := skAPI.KeyRing()
 
 	rsImpl := roomserver.NewInternalAPI(
 		base, keyRing,
@@ -134,7 +139,7 @@ func main() {
 		EDUInternalAPI:      eduInputAPI,
 		FederationSenderAPI: fsAPI,
 		RoomserverAPI:       rsAPI,
-		ServerKeyAPI:        serverKeyAPI,
+		ServerKeyAPI:        skAPI,
 		UserAPI:             userAPI,
 		KeyAPI:              keyAPI,
 	}
@@ -148,18 +153,18 @@ func main() {
 	// Expose the matrix APIs directly rather than putting them under a /api path.
 	go func() {
 		base.SetupAndServeHTTP(
-			config.HTTPAddress(httpAddr), // internal API
-			config.HTTPAddress(httpAddr), // external API
-			nil, nil,                     // TLS settings
+			httpAPIAddr, // internal API
+			httpAddr,    // external API
+			nil, nil,    // TLS settings
 		)
 	}()
 	// Handle HTTPS if certificate and key are provided
 	if *certFile != "" && *keyFile != "" {
 		go func() {
 			base.SetupAndServeHTTP(
-				config.HTTPAddress(httpsAddr), // internal API
-				config.HTTPAddress(httpsAddr), // external API
-				certFile, keyFile,             // TLS settings
+				setup.NoListener,  // internal API
+				httpsAddr,         // external API
+				certFile, keyFile, // TLS settings
 			)
 		}()
 	}
diff --git a/cmd/dendrite-room-server/main.go b/cmd/dendrite-room-server/main.go
index 08ad34bf..d3f14574 100644
--- a/cmd/dendrite-room-server/main.go
+++ b/cmd/dendrite-room-server/main.go
@@ -24,7 +24,7 @@ func main() {
 	base := setup.NewBaseDendrite(cfg, "RoomServerAPI", true)
 	defer base.Close() // nolint: errcheck
 
-	serverKeyAPI := base.ServerKeyAPIClient()
+	serverKeyAPI := base.SigningKeyServerHTTPClient()
 	keyRing := serverKeyAPI.KeyRing()
 
 	fsAPI := base.FederationSenderHTTPClient()
@@ -33,8 +33,8 @@ func main() {
 	roomserver.AddInternalRoutes(base.InternalAPIMux, rsAPI)
 
 	base.SetupAndServeHTTP(
-		base.Cfg.RoomServer.InternalAPI.Listen,
-		setup.NoExternalListener,
+		base.Cfg.RoomServer.InternalAPI.Listen, // internal listener
+		setup.NoListener,                       // external listener
 		nil, nil,
 	)
 }
diff --git a/cmd/dendrite-server-key-api-server/main.go b/cmd/dendrite-signing-key-server/main.go
index 1ad4ede2..a4d48d36 100644
--- a/cmd/dendrite-server-key-api-server/main.go
+++ b/cmd/dendrite-signing-key-server/main.go
@@ -16,22 +16,22 @@ package main
 
 import (
 	"github.com/matrix-org/dendrite/internal/setup"
-	"github.com/matrix-org/dendrite/serverkeyapi"
+	"github.com/matrix-org/dendrite/signingkeyserver"
 )
 
 func main() {
 	cfg := setup.ParseFlags(false)
-	base := setup.NewBaseDendrite(cfg, "ServerKeyAPI", true)
+	base := setup.NewBaseDendrite(cfg, "SigningKeyServer", true)
 	defer base.Close() // nolint: errcheck
 
 	federation := base.CreateFederationClient()
 
-	intAPI := serverkeyapi.NewInternalAPI(&base.Cfg.ServerKeyAPI, federation, base.Caches)
-	serverkeyapi.AddInternalRoutes(base.InternalAPIMux, intAPI, base.Caches)
+	intAPI := signingkeyserver.NewInternalAPI(&base.Cfg.SigningKeyServer, federation, base.Caches)
+	signingkeyserver.AddInternalRoutes(base.InternalAPIMux, intAPI, base.Caches)
 
 	base.SetupAndServeHTTP(
-		base.Cfg.ServerKeyAPI.InternalAPI.Listen,
-		setup.NoExternalListener,
+		base.Cfg.SigningKeyServer.InternalAPI.Listen,
+		setup.NoListener,
 		nil, nil,
 	)
 }
diff --git a/cmd/dendrite-user-api-server/main.go b/cmd/dendrite-user-api-server/main.go
index c8e2e2a3..fb65fefb 100644
--- a/cmd/dendrite-user-api-server/main.go
+++ b/cmd/dendrite-user-api-server/main.go
@@ -31,8 +31,8 @@ func main() {
 	userapi.AddInternalRoutes(base.InternalAPIMux, userAPI)
 
 	base.SetupAndServeHTTP(
-		base.Cfg.UserAPI.InternalAPI.Listen,
-		setup.NoExternalListener,
+		base.Cfg.UserAPI.InternalAPI.Listen, // internal listener
+		setup.NoListener,                    // external listener
 		nil, nil,
 	)
 }
diff --git a/cmd/dendritejs/main.go b/cmd/dendritejs/main.go
index 12dc2d7c..267259c7 100644
--- a/cmd/dendritejs/main.go
+++ b/cmd/dendritejs/main.go
@@ -168,7 +168,7 @@ func main() {
 	cfg.FederationSender.Database.ConnectionString = "file:/idb/dendritejs_fedsender.db"
 	cfg.MediaAPI.Database.ConnectionString = "file:/idb/dendritejs_mediaapi.db"
 	cfg.RoomServer.Database.ConnectionString = "file:/idb/dendritejs_roomserver.db"
-	cfg.ServerKeyAPI.Database.ConnectionString = "file:/idb/dendritejs_serverkey.db"
+	cfg.SigningKeyServer.Database.ConnectionString = "file:/idb/dendritejs_signingkeyserver.db"
 	cfg.SyncAPI.Database.ConnectionString = "file:/idb/dendritejs_syncapi.db"
 	cfg.KeyServer.Database.ConnectionString = "file:/idb/dendritejs_e2ekey.db"
 	cfg.Global.Kafka.UseNaffka = true
diff --git a/cmd/furl/main.go b/cmd/furl/main.go
new file mode 100644
index 00000000..3955ef0c
--- /dev/null
+++ b/cmd/furl/main.go
@@ -0,0 +1,124 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"crypto/ed25519"
+	"encoding/json"
+	"encoding/pem"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net/url"
+	"os"
+
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+var requestFrom = flag.String("from", "", "the server name that the request should originate from")
+var requestKey = flag.String("key", "matrix_key.pem", "the private key to use when signing the request")
+var requestPost = flag.Bool("post", false, "send a POST request instead of GET (pipe input into stdin or type followed by Ctrl-D)")
+
+// nolint:gocyclo
+func main() {
+	flag.Parse()
+
+	if requestFrom == nil || *requestFrom == "" {
+		fmt.Println("expecting: furl -from origin.com [-key matrix_key.pem] https://path/to/url")
+		fmt.Println("supported flags:")
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	data, err := ioutil.ReadFile(*requestKey)
+	if err != nil {
+		panic(err)
+	}
+
+	var privateKey ed25519.PrivateKey
+	keyBlock, _ := pem.Decode(data)
+	if keyBlock == nil {
+		panic("keyBlock is nil")
+	}
+	if keyBlock.Type == "MATRIX PRIVATE KEY" {
+		_, privateKey, err = ed25519.GenerateKey(bytes.NewReader(keyBlock.Bytes))
+		if err != nil {
+			panic(err)
+		}
+	} else {
+		panic("unexpected key block")
+	}
+
+	client := gomatrixserverlib.NewFederationClient(
+		gomatrixserverlib.ServerName(*requestFrom),
+		gomatrixserverlib.KeyID(keyBlock.Headers["Key-ID"]),
+		privateKey,
+		false,
+	)
+
+	u, err := url.Parse(flag.Arg(0))
+	if err != nil {
+		panic(err)
+	}
+
+	var bodyObj interface{}
+	var bodyBytes []byte
+	method := "GET"
+	if *requestPost {
+		method = "POST"
+		fmt.Println("Waiting for JSON input. Press Enter followed by Ctrl-D when done...")
+
+		scan := bufio.NewScanner(os.Stdin)
+		for scan.Scan() {
+			bytes := scan.Bytes()
+			bodyBytes = append(bodyBytes, bytes...)
+		}
+		fmt.Println("Done!")
+		if err = json.Unmarshal(bodyBytes, &bodyObj); err != nil {
+			panic(err)
+		}
+	}
+
+	req := gomatrixserverlib.NewFederationRequest(
+		method,
+		gomatrixserverlib.ServerName(u.Host),
+		u.RequestURI(),
+	)
+
+	if *requestPost {
+		if err = req.SetContent(bodyObj); err != nil {
+			panic(err)
+		}
+	}
+
+	if err = req.Sign(
+		gomatrixserverlib.ServerName(*requestFrom),
+		gomatrixserverlib.KeyID(keyBlock.Headers["Key-ID"]),
+		privateKey,
+	); err != nil {
+		panic(err)
+	}
+
+	httpReq, err := req.HTTPRequest()
+	if err != nil {
+		panic(err)
+	}
+
+	var res interface{}
+	err = client.DoRequestAndParseResponse(
+		context.TODO(),
+		httpReq,
+		&res,
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	j, err := json.MarshalIndent(res, "", "  ")
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(string(j))
+}
diff --git a/cmd/generate-config/main.go b/cmd/generate-config/main.go
index 78ed3af6..e65723e6 100644
--- a/cmd/generate-config/main.go
+++ b/cmd/generate-config/main.go
@@ -27,7 +27,7 @@ func main() {
 			},
 		},
 	}
-	cfg.ServerKeyAPI.KeyPerspectives = config.KeyPerspectives{
+	cfg.SigningKeyServer.KeyPerspectives = config.KeyPerspectives{
 		{
 			ServerName: "matrix.org",
 			Keys: []config.KeyPerspectiveTrustKey{
diff --git a/dendrite-config.yaml b/dendrite-config.yaml
index 74fa9b3e..6e87bc70 100644
--- a/dendrite-config.yaml
+++ b/dendrite-config.yaml
@@ -252,13 +252,13 @@ room_server:
     max_idle_conns: 2
     conn_max_lifetime: -1
 
-# Configuration for the Server Key API (for server signing keys).
-server_key_api:
+# Configuration for the Signing Key Server (for server signing keys).
+signing_key_server:
   internal_api:
     listen: http://localhost:7780
     connect: http://localhost:7780
   database:
-    connection_string: file:serverkeyapi.db
+    connection_string: file:signingkeyserver.db
     max_open_conns: 100
     max_idle_conns: 2
     conn_max_lifetime: -1
diff --git a/docs/INSTALL.md b/docs/INSTALL.md
index 7a7fb03e..913bc583 100644
--- a/docs/INSTALL.md
+++ b/docs/INSTALL.md
@@ -109,7 +109,7 @@ Assuming that Postgres 9.5 (or later) is installed:
 * Create the component databases:
 
   ```bash
-  for i in account device mediaapi syncapi roomserver serverkey federationsender appservice e2ekey naffka; do
+  for i in account device mediaapi syncapi roomserver signingkeyserver federationsender appservice e2ekey naffka; do
       sudo -u postgres createdb -O dendrite dendrite_$i
   done
   ```
diff --git a/federationapi/routing/devices.go b/federationapi/routing/devices.go
index 00631b9b..07862451 100644
--- a/federationapi/routing/devices.go
+++ b/federationapi/routing/devices.go
@@ -40,6 +40,7 @@ func GetUserDevices(
 	response := gomatrixserverlib.RespUserDevices{
 		UserID:   userID,
 		StreamID: res.StreamID,
+		Devices:  []gomatrixserverlib.RespUserDevice{},
 	}
 
 	for _, dev := range res.Devices {
diff --git a/federationsender/internal/perform.go b/federationsender/internal/perform.go
index 6aea296b..0c9dd257 100644
--- a/federationsender/internal/perform.go
+++ b/federationsender/internal/perform.go
@@ -232,7 +232,7 @@ func (r *FederationSenderInternalAPI) performJoinUsingServer(
 		// If we successfully performed a send_join above then the other
 		// server now thinks we're a part of the room. Send the newly
 		// returned state to the roomserver to update our local view.
-		if err = roomserverAPI.SendEventWithRewrite(
+		if err = roomserverAPI.SendEventWithState(
 			ctx, r.rsAPI,
 			respState,
 			event.Headered(respMakeJoin.RoomVersion),
diff --git a/go.mod b/go.mod
index 5793897a..c98aa61e 100644
--- a/go.mod
+++ b/go.mod
@@ -22,7 +22,7 @@ require (
 	github.com/matrix-org/go-http-js-libp2p v0.0.0-20200518170932-783164aeeda4
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3
 	github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20201005165532-90f2e192f625
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20201006143701-222e7423a5e3
 	github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91
 	github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4
 	github.com/mattn/go-sqlite3 v1.14.2
@@ -37,7 +37,7 @@ require (
 	github.com/tidwall/sjson v1.1.1
 	github.com/uber/jaeger-client-go v2.25.0+incompatible
 	github.com/uber/jaeger-lib v2.2.0+incompatible
-	github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200806125501-cd4685a3b4de
+	github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20201006093556-760d9a7fd5ee
 	go.uber.org/atomic v1.6.0
 	golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a
 	gopkg.in/h2non/bimg.v1 v1.1.4
diff --git a/go.sum b/go.sum
index 20479015..c92774bd 100644
--- a/go.sum
+++ b/go.sum
@@ -569,8 +569,8 @@ github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26 h1:Hr3zjRsq2bh
 github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26/go.mod h1:3fxX6gUjWyI/2Bt7J1OLhpCzOfO/bB3AiX0cJtEKud0=
 github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd h1:xVrqJK3xHREMNjwjljkAUaadalWc0rRbmVuQatzmgwg=
 github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd/go.mod h1:/gBX06Kw0exX1HrwmoBibFA98yBk/jxKpGVeyQbff+s=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20201005165532-90f2e192f625 h1:9ShgY0ZkfLzqe3gv18V5WxDAZ4dgUvJwnGORycox680=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20201005165532-90f2e192f625/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20201006143701-222e7423a5e3 h1:lWR/w6rXKZJJU1yGHb2zem/EK7+aYhUcRgAOiouZAxk=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20201006143701-222e7423a5e3/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91 h1:HJ6U3S3ljJqNffYMcIeAncp5qT/i+ZMiJ2JC2F0aXP4=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91/go.mod h1:sjyPyRxKM5uw1nD2cJ6O2OxI6GOqyVBfNXqKjBZTBZE=
 github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7 h1:ntrLa/8xVzeSs8vHFHK25k0C+NV74sYMJnNSg5NoSRo=
@@ -851,8 +851,8 @@ github.com/xdg/scram v0.0.0-20180814205039-7eeb5667e42c/go.mod h1:lB8K/P019DLNhe
 github.com/xdg/stringprep v1.0.0/go.mod h1:Jhud4/sHMO4oL310DaZAKk9ZaJ08SJfe+sJh0HrGL1Y=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yggdrasil-network/yggdrasil-extras v0.0.0-20200525205615-6c8a4a2e8855/go.mod h1:xQdsh08Io6nV4WRnOVTe6gI8/2iTvfLDQ0CYa5aMt+I=
-github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200806125501-cd4685a3b4de h1:p91aw0Mvol825U+5bvV9BBPl+HQxIczj7wxIOxZs70M=
-github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200806125501-cd4685a3b4de/go.mod h1:d+Nz6SPeG6kmeSPFL0cvfWfgwEql75fUnZiAONgvyBE=
+github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20201006093556-760d9a7fd5ee h1:Kot820OfxWfYrk5di5f4S5s0jXXrQj8w8BG5826HAv4=
+github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20201006093556-760d9a7fd5ee/go.mod h1:d+Nz6SPeG6kmeSPFL0cvfWfgwEql75fUnZiAONgvyBE=
 go.opencensus.io v0.18.0/go.mod h1:vKdFvxhtzZ9onBp9VKHK8z/sRpBMnKAsufL7wlDrCOA=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.1/go.mod h1:Ap50jQcDJrx6rB6VgeeFPtuPIf3wMRvRfrfYDO6+BmA=
diff --git a/internal/config/config.go b/internal/config/config.go
index 74d3f4fa..9d9e2414 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -62,7 +62,7 @@ type Dendrite struct {
 	KeyServer        KeyServer        `yaml:"key_server"`
 	MediaAPI         MediaAPI         `yaml:"media_api"`
 	RoomServer       RoomServer       `yaml:"room_server"`
-	ServerKeyAPI     ServerKeyAPI     `yaml:"server_key_api"`
+	SigningKeyServer SigningKeyServer `yaml:"signing_key_server"`
 	SyncAPI          SyncAPI          `yaml:"sync_api"`
 	UserAPI          UserAPI          `yaml:"user_api"`
 
@@ -302,7 +302,7 @@ func (c *Dendrite) Defaults() {
 	c.KeyServer.Defaults()
 	c.MediaAPI.Defaults()
 	c.RoomServer.Defaults()
-	c.ServerKeyAPI.Defaults()
+	c.SigningKeyServer.Defaults()
 	c.SyncAPI.Defaults()
 	c.UserAPI.Defaults()
 	c.AppServiceAPI.Defaults()
@@ -318,7 +318,7 @@ func (c *Dendrite) Verify(configErrs *ConfigErrors, isMonolith bool) {
 		&c.Global, &c.ClientAPI,
 		&c.EDUServer, &c.FederationAPI, &c.FederationSender,
 		&c.KeyServer, &c.MediaAPI, &c.RoomServer,
-		&c.ServerKeyAPI, &c.SyncAPI, &c.UserAPI,
+		&c.SigningKeyServer, &c.SyncAPI, &c.UserAPI,
 		&c.AppServiceAPI,
 	} {
 		c.Verify(configErrs, isMonolith)
@@ -333,7 +333,7 @@ func (c *Dendrite) Wiring() {
 	c.KeyServer.Matrix = &c.Global
 	c.MediaAPI.Matrix = &c.Global
 	c.RoomServer.Matrix = &c.Global
-	c.ServerKeyAPI.Matrix = &c.Global
+	c.SigningKeyServer.Matrix = &c.Global
 	c.SyncAPI.Matrix = &c.Global
 	c.UserAPI.Matrix = &c.Global
 	c.AppServiceAPI.Matrix = &c.Global
@@ -524,13 +524,13 @@ func (config *Dendrite) FederationSenderURL() string {
 	return string(config.FederationSender.InternalAPI.Connect)
 }
 
-// ServerKeyAPIURL returns an HTTP URL for where the server key API is listening.
-func (config *Dendrite) ServerKeyAPIURL() string {
-	// Hard code the server key API server to talk HTTP for now.
+// SigningKeyServerURL returns an HTTP URL for where the signing key server is listening.
+func (config *Dendrite) SigningKeyServerURL() string {
+	// Hard code the signing key server to talk HTTP for now.
 	// If we support HTTPS we need to think of a practical way to do certificate validation.
 	// People setting up servers shouldn't need to get a certificate valid for the public
 	// internet for an internal API.
-	return string(config.ServerKeyAPI.InternalAPI.Connect)
+	return string(config.SigningKeyServer.InternalAPI.Connect)
 }
 
 // KeyServerURL returns an HTTP URL for where the key server is listening.
diff --git a/internal/config/config_serverkey.go b/internal/config/config_signingkeyserver.go
index 788a2fa0..51aca38b 100644
--- a/internal/config/config_serverkey.go
+++ b/internal/config/config_signingkeyserver.go
@@ -2,12 +2,12 @@ package config
 
 import "github.com/matrix-org/gomatrixserverlib"
 
-type ServerKeyAPI struct {
+type SigningKeyServer struct {
 	Matrix *Global `yaml:"-"`
 
 	InternalAPI InternalAPIOptions `yaml:"internal_api"`
 
-	// The ServerKey database caches the public keys of remote servers.
+	// The SigningKeyServer database caches the public keys of remote servers.
 	// It may be accessed by the FederationAPI, the ClientAPI, and the MediaAPI.
 	Database DatabaseOptions `yaml:"database"`
 
@@ -19,17 +19,17 @@ type ServerKeyAPI struct {
 	PreferDirectFetch bool `yaml:"prefer_direct_fetch"`
 }
 
-func (c *ServerKeyAPI) Defaults() {
+func (c *SigningKeyServer) Defaults() {
 	c.InternalAPI.Listen = "http://localhost:7780"
 	c.InternalAPI.Connect = "http://localhost:7780"
 	c.Database.Defaults()
-	c.Database.ConnectionString = "file:serverkeyapi.db"
+	c.Database.ConnectionString = "file:signingkeyserver.db"
 }
 
-func (c *ServerKeyAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
-	checkURL(configErrs, "server_key_api.internal_api.listen", string(c.InternalAPI.Listen))
-	checkURL(configErrs, "server_key_api.internal_api.bind", string(c.InternalAPI.Connect))
-	checkNotEmpty(configErrs, "server_key_api.database.connection_string", string(c.Database.ConnectionString))
+func (c *SigningKeyServer) Verify(configErrs *ConfigErrors, isMonolith bool) {
+	checkURL(configErrs, "signing_key_server.internal_api.listen", string(c.InternalAPI.Listen))
+	checkURL(configErrs, "signing_key_server.internal_api.bind", string(c.InternalAPI.Connect))
+	checkNotEmpty(configErrs, "signing_key_server.database.connection_string", string(c.Database.ConnectionString))
 }
 
 // KeyPerspectives are used to configure perspective key servers for
diff --git a/internal/setup/base.go b/internal/setup/base.go
index f9ddfdf7..77fdb04a 100644
--- a/internal/setup/base.go
+++ b/internal/setup/base.go
@@ -46,8 +46,8 @@ import (
 	keyinthttp "github.com/matrix-org/dendrite/keyserver/inthttp"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	rsinthttp "github.com/matrix-org/dendrite/roomserver/inthttp"
-	serverKeyAPI "github.com/matrix-org/dendrite/serverkeyapi/api"
-	skinthttp "github.com/matrix-org/dendrite/serverkeyapi/inthttp"
+	skapi "github.com/matrix-org/dendrite/signingkeyserver/api"
+	skinthttp "github.com/matrix-org/dendrite/signingkeyserver/inthttp"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
 	userapiinthttp "github.com/matrix-org/dendrite/userapi/inthttp"
 	"github.com/sirupsen/logrus"
@@ -80,7 +80,7 @@ type BaseDendrite struct {
 const HTTPServerTimeout = time.Minute * 5
 const HTTPClientTimeout = time.Second * 30
 
-const NoExternalListener = ""
+const NoListener = ""
 
 // NewBaseDendrite creates a new instance to be used by a component.
 // The componentName is used for logging purposes, and should be a friendly name
@@ -208,15 +208,15 @@ func (b *BaseDendrite) FederationSenderHTTPClient() federationSenderAPI.Federati
 	return f
 }
 
-// ServerKeyAPIClient returns ServerKeyInternalAPI for hitting the server key API over HTTP
-func (b *BaseDendrite) ServerKeyAPIClient() serverKeyAPI.ServerKeyInternalAPI {
-	f, err := skinthttp.NewServerKeyClient(
-		b.Cfg.ServerKeyAPIURL(),
+// SigningKeyServerHTTPClient returns SigningKeyServer for hitting the signing key server over HTTP
+func (b *BaseDendrite) SigningKeyServerHTTPClient() skapi.SigningKeyServerAPI {
+	f, err := skinthttp.NewSigningKeyServerClient(
+		b.Cfg.SigningKeyServerURL(),
 		b.apiHttpClient,
 		b.Caches,
 	)
 	if err != nil {
-		logrus.WithError(err).Panic("NewServerKeyInternalAPIHTTP failed", b.httpClient)
+		logrus.WithError(err).Panic("SigningKeyServerHTTPClient failed", b.httpClient)
 	}
 	return f
 }
@@ -272,22 +272,21 @@ func (b *BaseDendrite) SetupAndServeHTTP(
 	internalAddr, _ := internalHTTPAddr.Address()
 	externalAddr, _ := externalHTTPAddr.Address()
 
-	internalRouter := mux.NewRouter().SkipClean(true).UseEncodedPath()
-	externalRouter := internalRouter
+	externalRouter := mux.NewRouter().SkipClean(true).UseEncodedPath()
+	internalRouter := externalRouter
 
-	internalServ := &http.Server{
-		Addr:         string(internalAddr),
+	externalServ := &http.Server{
+		Addr:         string(externalAddr),
 		WriteTimeout: HTTPServerTimeout,
-		Handler:      internalRouter,
+		Handler:      externalRouter,
 	}
-	externalServ := internalServ
-
-	if externalAddr != NoExternalListener && externalAddr != internalAddr {
-		externalRouter = mux.NewRouter().SkipClean(true).UseEncodedPath()
-		externalServ = &http.Server{
-			Addr:         string(externalAddr),
-			WriteTimeout: HTTPServerTimeout,
-			Handler:      externalRouter,
+	internalServ := externalServ
+
+	if internalAddr != NoListener && externalAddr != internalAddr {
+		internalRouter = mux.NewRouter().SkipClean(true).UseEncodedPath()
+		internalServ = &http.Server{
+			Addr:    string(internalAddr),
+			Handler: internalRouter,
 		}
 	}
 
@@ -301,23 +300,25 @@ func (b *BaseDendrite) SetupAndServeHTTP(
 	externalRouter.PathPrefix(httputil.PublicFederationPathPrefix).Handler(b.PublicFederationAPIMux)
 	externalRouter.PathPrefix(httputil.PublicMediaPathPrefix).Handler(b.PublicMediaAPIMux)
 
-	go func() {
-		logrus.Infof("Starting %s listener on %s", b.componentName, internalServ.Addr)
-		if certFile != nil && keyFile != nil {
-			if err := internalServ.ListenAndServeTLS(*certFile, *keyFile); err != nil {
-				logrus.WithError(err).Fatal("failed to serve HTTPS")
-			}
-		} else {
-			if err := internalServ.ListenAndServe(); err != nil {
-				logrus.WithError(err).Fatal("failed to serve HTTP")
+	if internalAddr != NoListener && internalAddr != externalAddr {
+		go func() {
+			logrus.Infof("Starting internal %s listener on %s", b.componentName, internalServ.Addr)
+			if certFile != nil && keyFile != nil {
+				if err := internalServ.ListenAndServeTLS(*certFile, *keyFile); err != nil {
+					logrus.WithError(err).Fatal("failed to serve HTTPS")
+				}
+			} else {
+				if err := internalServ.ListenAndServe(); err != nil {
+					logrus.WithError(err).Fatal("failed to serve HTTP")
+				}
 			}
-		}
-		logrus.Infof("Stopped %s listener on %s", b.componentName, internalServ.Addr)
-	}()
+			logrus.Infof("Stopped internal %s listener on %s", b.componentName, internalServ.Addr)
+		}()
+	}
 
-	if externalAddr != NoExternalListener && internalAddr != externalAddr {
+	if externalAddr != NoListener {
 		go func() {
-			logrus.Infof("Starting %s listener on %s", b.componentName, externalServ.Addr)
+			logrus.Infof("Starting external %s listener on %s", b.componentName, externalServ.Addr)
 			if certFile != nil && keyFile != nil {
 				if err := externalServ.ListenAndServeTLS(*certFile, *keyFile); err != nil {
 					logrus.WithError(err).Fatal("failed to serve HTTPS")
@@ -327,7 +328,7 @@ func (b *BaseDendrite) SetupAndServeHTTP(
 					logrus.WithError(err).Fatal("failed to serve HTTP")
 				}
 			}
-			logrus.Infof("Stopped %s listener on %s", b.componentName, externalServ.Addr)
+			logrus.Infof("Stopped external %s listener on %s", b.componentName, externalServ.Addr)
 		}()
 	}
 
diff --git a/internal/setup/monolith.go b/internal/setup/monolith.go
index 2274283e..a0675d61 100644
--- a/internal/setup/monolith.go
+++ b/internal/setup/monolith.go
@@ -28,7 +28,7 @@ import (
 	keyAPI "github.com/matrix-org/dendrite/keyserver/api"
 	"github.com/matrix-org/dendrite/mediaapi"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
-	serverKeyAPI "github.com/matrix-org/dendrite/serverkeyapi/api"
+	serverKeyAPI "github.com/matrix-org/dendrite/signingkeyserver/api"
 	"github.com/matrix-org/dendrite/syncapi"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/dendrite/userapi/storage/accounts"
@@ -50,7 +50,7 @@ type Monolith struct {
 	EDUInternalAPI      eduServerAPI.EDUServerInputAPI
 	FederationSenderAPI federationSenderAPI.FederationSenderInternalAPI
 	RoomserverAPI       roomserverAPI.RoomserverInternalAPI
-	ServerKeyAPI        serverKeyAPI.ServerKeyInternalAPI
+	ServerKeyAPI        serverKeyAPI.SigningKeyServerAPI
 	UserAPI             userapi.UserInternalAPI
 	KeyAPI              keyAPI.KeyInternalAPI
 
diff --git a/internal/test/config.go b/internal/test/config.go
index 8080988f..69fc5a87 100644
--- a/internal/test/config.go
+++ b/internal/test/config.go
@@ -92,7 +92,7 @@ func MakeConfig(configDir, kafkaURI, database, host string, startPort int) (*con
 	cfg.KeyServer.Database.ConnectionString = config.DataSource(database)
 	cfg.MediaAPI.Database.ConnectionString = config.DataSource(database)
 	cfg.RoomServer.Database.ConnectionString = config.DataSource(database)
-	cfg.ServerKeyAPI.Database.ConnectionString = config.DataSource(database)
+	cfg.SigningKeyServer.Database.ConnectionString = config.DataSource(database)
 	cfg.SyncAPI.Database.ConnectionString = config.DataSource(database)
 	cfg.UserAPI.AccountDatabase.ConnectionString = config.DataSource(database)
 	cfg.UserAPI.DeviceDatabase.ConnectionString = config.DataSource(database)
@@ -104,7 +104,7 @@ func MakeConfig(configDir, kafkaURI, database, host string, startPort int) (*con
 	cfg.KeyServer.InternalAPI.Listen = assignAddress()
 	cfg.MediaAPI.InternalAPI.Listen = assignAddress()
 	cfg.RoomServer.InternalAPI.Listen = assignAddress()
-	cfg.ServerKeyAPI.InternalAPI.Listen = assignAddress()
+	cfg.SigningKeyServer.InternalAPI.Listen = assignAddress()
 	cfg.SyncAPI.InternalAPI.Listen = assignAddress()
 	cfg.UserAPI.InternalAPI.Listen = assignAddress()
 
@@ -115,7 +115,7 @@ func MakeConfig(configDir, kafkaURI, database, host string, startPort int) (*con
 	cfg.KeyServer.InternalAPI.Connect = cfg.KeyServer.InternalAPI.Listen
 	cfg.MediaAPI.InternalAPI.Connect = cfg.MediaAPI.InternalAPI.Listen
 	cfg.RoomServer.InternalAPI.Connect = cfg.RoomServer.InternalAPI.Listen
-	cfg.ServerKeyAPI.InternalAPI.Connect = cfg.ServerKeyAPI.InternalAPI.Listen
+	cfg.SigningKeyServer.InternalAPI.Connect = cfg.SigningKeyServer.InternalAPI.Listen
 	cfg.SyncAPI.InternalAPI.Connect = cfg.SyncAPI.InternalAPI.Listen
 	cfg.UserAPI.InternalAPI.Connect = cfg.UserAPI.InternalAPI.Listen
 
diff --git a/roomserver/api/input.go b/roomserver/api/input.go
index 862a6fa1..dd693203 100644
--- a/roomserver/api/input.go
+++ b/roomserver/api/input.go
@@ -32,13 +32,6 @@ const (
 	// there was a new event that references an event that we don't
 	// have a copy of.
 	KindNew = 2
-	// KindBackfill event extend the contiguous graph going backwards.
-	// They always have state.
-	KindBackfill = 3
-	// KindRewrite events are used when rewriting the head of the room
-	// graph with entirely new state. The output events generated will
-	// be state events rather than timeline events.
-	KindRewrite = 4
 )
 
 // DoNotSendToOtherServers tells us not to send the event to other matrix
diff --git a/roomserver/api/wrapper.go b/roomserver/api/wrapper.go
index 24949fc6..a38c00df 100644
--- a/roomserver/api/wrapper.go
+++ b/roomserver/api/wrapper.go
@@ -80,99 +80,6 @@ func SendEventWithState(
 	return SendInputRoomEvents(ctx, rsAPI, ires)
 }
 
-// SendEventWithRewrite writes an event with KindNew to the roomserver along
-// with a number of rewrite and outlier events for state and auth events
-// respectively.
-func SendEventWithRewrite(
-	ctx context.Context, rsAPI RoomserverInternalAPI, state *gomatrixserverlib.RespState,
-	event gomatrixserverlib.HeaderedEvent, haveEventIDs map[string]bool,
-) error {
-	isCurrentState := map[string]struct{}{}
-	for _, se := range state.StateEvents {
-		isCurrentState[se.EventID()] = struct{}{}
-	}
-
-	authAndStateEvents, err := state.Events()
-	if err != nil {
-		return err
-	}
-
-	var ires []InputRoomEvent
-	var stateIDs []string
-
-	// This function generates three things:
-	// A - A set of "rewrite" events, which will form the newly rewritten
-	//     state before the event, which includes every rewrite event that
-	//     came before it in its state
-	// B - A set of "outlier" events, which are auth events but not part
-	//     of the rewritten state
-	// C - A "new" event, which include all of the rewrite events in its
-	//     state
-	for _, authOrStateEvent := range authAndStateEvents {
-		if authOrStateEvent.StateKey() == nil {
-			continue
-		}
-		if haveEventIDs[authOrStateEvent.EventID()] {
-			continue
-		}
-		if event.StateKey() == nil {
-			continue
-		}
-
-		// We will handle an event as if it's an outlier if one of the
-		// following conditions is true:
-		storeAsOutlier := false
-		if _, ok := isCurrentState[authOrStateEvent.EventID()]; !ok {
-			// The event is an auth event and isn't a part of the state set.
-			// We'll send it as an outlier because we need it to be stored
-			// in case something is referring to it as an auth event.
-			storeAsOutlier = true
-		}
-
-		if storeAsOutlier {
-			ires = append(ires, InputRoomEvent{
-				Kind:         KindOutlier,
-				Event:        authOrStateEvent.Headered(event.RoomVersion),
-				AuthEventIDs: authOrStateEvent.AuthEventIDs(),
-			})
-			continue
-		}
-
-		// If the event isn't an outlier then we'll instead send it as a
-		// rewrite event, so that it'll form part of the rewritten state.
-		// These events will go through the membership and latest event
-		// updaters and we will generate output events, but they will be
-		// flagged as non-current (i.e. didn't just happen) events.
-		// Each of these rewrite events includes all of the rewrite events
-		// that came before in their StateEventIDs.
-		ires = append(ires, InputRoomEvent{
-			Kind:          KindRewrite,
-			Event:         authOrStateEvent.Headered(event.RoomVersion),
-			AuthEventIDs:  authOrStateEvent.AuthEventIDs(),
-			HasState:      true,
-			StateEventIDs: stateIDs,
-		})
-
-		// Add the event ID into the StateEventIDs of all subsequent
-		// rewrite events, and the new event.
-		stateIDs = append(stateIDs, authOrStateEvent.EventID())
-	}
-
-	// Send the final event as a new event, which will generate
-	// a timeline output event for it. All of the rewrite events
-	// that came before will be sent as StateEventIDs, forming a
-	// new clean state before the event.
-	ires = append(ires, InputRoomEvent{
-		Kind:          KindNew,
-		Event:         event,
-		AuthEventIDs:  event.AuthEventIDs(),
-		HasState:      true,
-		StateEventIDs: stateIDs,
-	})
-
-	return SendInputRoomEvents(ctx, rsAPI, ires)
-}
-
 // SendInputRoomEvents to the roomserver.
 func SendInputRoomEvents(
 	ctx context.Context, rsAPI RoomserverInternalAPI, ires []InputRoomEvent,
diff --git a/roomserver/internal/api.go b/roomserver/internal/api.go
index 8dc1a170..ee4e4ec9 100644
--- a/roomserver/internal/api.go
+++ b/roomserver/internal/api.go
@@ -26,28 +26,30 @@ type RoomserverInternalAPI struct {
 	*perform.Leaver
 	*perform.Publisher
 	*perform.Backfiller
-	DB                   storage.Database
-	Cfg                  *config.RoomServer
-	Producer             sarama.SyncProducer
-	Cache                caching.RoomServerCaches
-	ServerName           gomatrixserverlib.ServerName
-	KeyRing              gomatrixserverlib.JSONVerifier
-	fsAPI                fsAPI.FederationSenderInternalAPI
-	OutputRoomEventTopic string // Kafka topic for new output room events
+	DB                     storage.Database
+	Cfg                    *config.RoomServer
+	Producer               sarama.SyncProducer
+	Cache                  caching.RoomServerCaches
+	ServerName             gomatrixserverlib.ServerName
+	KeyRing                gomatrixserverlib.JSONVerifier
+	fsAPI                  fsAPI.FederationSenderInternalAPI
+	OutputRoomEventTopic   string // Kafka topic for new output room events
+	PerspectiveServerNames []gomatrixserverlib.ServerName
 }
 
 func NewRoomserverAPI(
 	cfg *config.RoomServer, roomserverDB storage.Database, producer sarama.SyncProducer,
 	outputRoomEventTopic string, caches caching.RoomServerCaches,
-	keyRing gomatrixserverlib.JSONVerifier,
+	keyRing gomatrixserverlib.JSONVerifier, perspectiveServerNames []gomatrixserverlib.ServerName,
 ) *RoomserverInternalAPI {
 	serverACLs := acls.NewServerACLs(roomserverDB)
 	a := &RoomserverInternalAPI{
-		DB:         roomserverDB,
-		Cfg:        cfg,
-		Cache:      caches,
-		ServerName: cfg.Matrix.ServerName,
-		KeyRing:    keyRing,
+		DB:                     roomserverDB,
+		Cfg:                    cfg,
+		Cache:                  caches,
+		ServerName:             cfg.Matrix.ServerName,
+		PerspectiveServerNames: perspectiveServerNames,
+		KeyRing:                keyRing,
 		Queryer: &query.Queryer{
 			DB:         roomserverDB,
 			Cache:      caches,
@@ -105,6 +107,10 @@ func (r *RoomserverInternalAPI) SetFederationSenderAPI(fsAPI fsAPI.FederationSen
 		DB:         r.DB,
 		FSAPI:      r.fsAPI,
 		KeyRing:    r.KeyRing,
+		// Perspective servers are trusted to not lie about server keys, so we will also
+		// prefer these servers when backfilling (assuming they are in the room) rather
+		// than trying random servers
+		PreferServers: r.PerspectiveServerNames,
 	}
 }
 
diff --git a/roomserver/internal/helpers/helpers.go b/roomserver/internal/helpers/helpers.go
index b7e6ce86..a2fbd287 100644
--- a/roomserver/internal/helpers/helpers.go
+++ b/roomserver/internal/helpers/helpers.go
@@ -2,6 +2,8 @@ package helpers
 
 import (
 	"context"
+	"database/sql"
+	"errors"
 	"fmt"
 
 	"github.com/matrix-org/dendrite/roomserver/api"
@@ -217,6 +219,9 @@ func CheckServerAllowedToSeeEvent(
 	roomState := state.NewStateResolution(db, info)
 	stateEntries, err := roomState.LoadStateAtEvent(ctx, eventID)
 	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return false, nil
+		}
 		return false, err
 	}
 
diff --git a/roomserver/internal/input/input_events.go b/roomserver/internal/input/input_events.go
index 3d44f048..11334159 100644
--- a/roomserver/internal/input/input_events.go
+++ b/roomserver/internal/input/input_events.go
@@ -54,7 +54,7 @@ func (r *Inputer) processRoomEvent(
 	}
 
 	var softfail bool
-	if input.Kind == api.KindBackfill || input.Kind == api.KindNew {
+	if input.Kind == api.KindNew {
 		// Check that the event passes authentication checks based on the
 		// current room state.
 		softfail, err = helpers.CheckForSoftFail(ctx, r.DB, headered, input.StateEventIDs)
@@ -136,15 +136,6 @@ func (r *Inputer) processRoomEvent(
 		return event.EventID(), rejectionErr
 	}
 
-	if input.Kind == api.KindRewrite {
-		logrus.WithFields(logrus.Fields{
-			"event_id": event.EventID(),
-			"type":     event.Type(),
-			"room":     event.RoomID(),
-		}).Debug("Stored rewrite")
-		return event.EventID(), nil
-	}
-
 	if err = r.updateLatestEvents(
 		ctx,                 // context
 		roomInfo,            // room info for the room being updated
diff --git a/roomserver/internal/input/input_latest_events.go b/roomserver/internal/input/input_latest_events.go
index 2e9f3b4e..7be6372b 100644
--- a/roomserver/internal/input/input_latest_events.go
+++ b/roomserver/internal/input/input_latest_events.go
@@ -28,6 +28,7 @@ import (
 	"github.com/matrix-org/dendrite/roomserver/types"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
+	"github.com/sirupsen/logrus"
 )
 
 // updateLatestEvents updates the list of latest events for this room in the database and writes the
@@ -116,7 +117,6 @@ type latestEventsUpdater struct {
 }
 
 func (u *latestEventsUpdater) doUpdateLatestEvents() error {
-	prevEvents := u.event.PrevEvents()
 	u.lastEventIDSent = u.updater.LastEventIDSent()
 	u.oldStateNID = u.updater.CurrentStateSnapshotNID()
 
@@ -140,30 +140,12 @@ func (u *latestEventsUpdater) doUpdateLatestEvents() error {
 		return nil
 	}
 
-	// Update the roomserver_previous_events table with references. This
-	// is effectively tracking the structure of the DAG.
-	if err = u.updater.StorePreviousEvents(u.stateAtEvent.EventNID, prevEvents); err != nil {
-		return fmt.Errorf("u.updater.StorePreviousEvents: %w", err)
-	}
-
-	// Get the event reference for our new event. This will be used when
-	// determining if the event is referenced by an existing event.
-	eventReference := u.event.EventReference()
-
-	// Check if our new event is already referenced by an existing event
-	// in the room. If it is then it isn't a latest event.
-	alreadyReferenced, err := u.updater.IsReferenced(eventReference)
-	if err != nil {
-		return fmt.Errorf("u.updater.IsReferenced: %w", err)
-	}
-
-	// Work out what the latest events are.
-	u.latest = calculateLatest(
+	// Work out what the latest events are. This will include the new
+	// event if it is not already referenced.
+	u.calculateLatest(
 		oldLatest,
-		alreadyReferenced,
-		prevEvents,
 		types.StateAtEventAndReference{
-			EventReference: eventReference,
+			EventReference: u.event.EventReference(),
 			StateAtEvent:   u.stateAtEvent,
 		},
 	)
@@ -215,27 +197,12 @@ func (u *latestEventsUpdater) latestState() error {
 	var err error
 	roomState := state.NewStateResolution(u.api.DB, *u.roomInfo)
 
-	// Get a list of the current room state events if available.
-	var currentState []types.StateEntry
-	if u.roomInfo.StateSnapshotNID != 0 {
-		currentState, _ = roomState.LoadStateAtSnapshot(u.ctx, u.roomInfo.StateSnapshotNID)
-	}
-
-	// Get a list of the current latest events. This will include both
-	// the current room state and the latest events after the input event.
-	// The idea is that we will perform state resolution on this set and
-	// any conflicting events will be resolved properly.
-	latestStateAtEvents := make([]types.StateAtEvent, len(u.latest)+len(currentState))
-	offset := 0
-	for i := range currentState {
-		latestStateAtEvents[i] = types.StateAtEvent{
-			BeforeStateSnapshotNID: u.roomInfo.StateSnapshotNID,
-			StateEntry:             currentState[i],
-		}
-		offset++
-	}
+	// Get a list of the current latest events. This may or may not
+	// include the new event from the input path, depending on whether
+	// it is a forward extremity or not.
+	latestStateAtEvents := make([]types.StateAtEvent, len(u.latest))
 	for i := range u.latest {
-		latestStateAtEvents[offset+i] = u.latest[i].StateAtEvent
+		latestStateAtEvents[i] = u.latest[i].StateAtEvent
 	}
 
 	// Takes the NIDs of the latest events and creates a state snapshot
@@ -266,6 +233,14 @@ func (u *latestEventsUpdater) latestState() error {
 	if err != nil {
 		return fmt.Errorf("roomState.DifferenceBetweenStateSnapshots: %w", err)
 	}
+	if len(u.removed) > len(u.added) {
+		// This really shouldn't happen.
+		// TODO: What is ultimately the best way to handle this situation?
+		return fmt.Errorf(
+			"invalid state delta wants to remove %d state but only add %d state (between state snapshots %d and %d)",
+			len(u.removed), len(u.added), u.oldStateNID, u.newStateNID,
+		)
+	}
 
 	// Also work out the state before the event removes and the event
 	// adds.
@@ -279,42 +254,49 @@ func (u *latestEventsUpdater) latestState() error {
 	return nil
 }
 
-func calculateLatest(
+func (u *latestEventsUpdater) calculateLatest(
 	oldLatest []types.StateAtEventAndReference,
-	alreadyReferenced bool,
-	prevEvents []gomatrixserverlib.EventReference,
 	newEvent types.StateAtEventAndReference,
-) []types.StateAtEventAndReference {
-	var alreadyInLatest bool
+) {
 	var newLatest []types.StateAtEventAndReference
+
+	// First of all, let's see if any of the existing forward extremities
+	// now have entries in the previous events table. If they do then we
+	// will no longer include them as forward extremities.
 	for _, l := range oldLatest {
-		keep := true
-		for _, prevEvent := range prevEvents {
-			if l.EventID == prevEvent.EventID && bytes.Equal(l.EventSHA256, prevEvent.EventSHA256) {
-				// This event can be removed from the latest events cause we've found an event that references it.
-				// (If an event is referenced by another event then it can't be one of the latest events in the room
-				//  because we have an event that comes after it)
-				keep = false
-				break
-			}
-		}
-		if l.EventNID == newEvent.EventNID {
-			alreadyInLatest = true
-		}
-		if keep {
-			// Keep the event in the latest events.
+		referenced, err := u.updater.IsReferenced(l.EventReference)
+		if err != nil {
+			logrus.WithError(err).Errorf("Failed to retrieve event reference for %q", l.EventID)
+		} else if !referenced {
 			newLatest = append(newLatest, l)
 		}
 	}
 
-	if !alreadyReferenced && !alreadyInLatest {
-		// This event is not referenced by any of the events in the room
-		// and the event is not already in the latest events.
-		// Add it to the latest events
+	// Then check and see if our new event is already included in that set.
+	// This ordinarily won't happen but it covers the edge-case that we've
+	// already seen this event before and it's a forward extremity, so rather
+	// than adding a duplicate, we'll just return the set as complete.
+	for _, l := range newLatest {
+		if l.EventReference.EventID == newEvent.EventReference.EventID && bytes.Equal(l.EventReference.EventSHA256, newEvent.EventReference.EventSHA256) {
+			// We've already referenced this new event so we can just return
+			// the newly completed extremities at this point.
+			u.latest = newLatest
+			return
+		}
+	}
+
+	// At this point we've processed the old extremities, and we've checked
+	// that our new event isn't already in that set. Therefore now we can
+	// check if our *new* event is a forward extremity, and if it is, add
+	// it in.
+	referenced, err := u.updater.IsReferenced(newEvent.EventReference)
+	if err != nil {
+		logrus.WithError(err).Errorf("Failed to retrieve event reference for %q", newEvent.EventReference.EventID)
+	} else if !referenced {
 		newLatest = append(newLatest, newEvent)
 	}
 
-	return newLatest
+	u.latest = newLatest
 }
 
 func (u *latestEventsUpdater) makeOutputNewRoomEvent() (*api.OutputEvent, error) {
diff --git a/roomserver/internal/perform/perform_backfill.go b/roomserver/internal/perform/perform_backfill.go
index eb1aa99b..d90ac8fc 100644
--- a/roomserver/internal/perform/perform_backfill.go
+++ b/roomserver/internal/perform/perform_backfill.go
@@ -30,11 +30,19 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// the max number of servers to backfill from per request. If this is too low we may fail to backfill when
+// we could've from another server. If this is too high we may take far too long to successfully backfill
+// as we try dead servers.
+const maxBackfillServers = 5
+
 type Backfiller struct {
 	ServerName gomatrixserverlib.ServerName
 	DB         storage.Database
 	FSAPI      federationSenderAPI.FederationSenderInternalAPI
 	KeyRing    gomatrixserverlib.JSONVerifier
+
+	// The servers which should be preferred above other servers when backfilling
+	PreferServers []gomatrixserverlib.ServerName
 }
 
 // PerformBackfill implements api.RoomServerQueryAPI
@@ -96,7 +104,7 @@ func (r *Backfiller) backfillViaFederation(ctx context.Context, req *api.Perform
 	if info == nil || info.IsStub {
 		return fmt.Errorf("backfillViaFederation: missing room info for room %s", req.RoomID)
 	}
-	requester := newBackfillRequester(r.DB, r.FSAPI, r.ServerName, req.BackwardsExtremities)
+	requester := newBackfillRequester(r.DB, r.FSAPI, r.ServerName, req.BackwardsExtremities, r.PreferServers)
 	// Request 100 items regardless of what the query asks for.
 	// We don't want to go much higher than this.
 	// We can't honour exactly the limit as some sytests rely on requesting more for tests to pass
@@ -195,7 +203,7 @@ func (r *Backfiller) fetchAndStoreMissingEvents(ctx context.Context, roomVer gom
 			logger.Infof("returned %d PDUs which made events %+v", len(res.PDUs), result)
 			for _, res := range result {
 				if res.Error != nil {
-					logger.WithError(err).Warn("event failed PDU checks")
+					logger.WithError(res.Error).Warn("event failed PDU checks")
 					continue
 				}
 				missingMap[id] = res.Event
@@ -215,10 +223,11 @@ func (r *Backfiller) fetchAndStoreMissingEvents(ctx context.Context, roomVer gom
 
 // backfillRequester implements gomatrixserverlib.BackfillRequester
 type backfillRequester struct {
-	db         storage.Database
-	fsAPI      federationSenderAPI.FederationSenderInternalAPI
-	thisServer gomatrixserverlib.ServerName
-	bwExtrems  map[string][]string
+	db           storage.Database
+	fsAPI        federationSenderAPI.FederationSenderInternalAPI
+	thisServer   gomatrixserverlib.ServerName
+	preferServer map[gomatrixserverlib.ServerName]bool
+	bwExtrems    map[string][]string
 
 	// per-request state
 	servers                 []gomatrixserverlib.ServerName
@@ -226,7 +235,14 @@ type backfillRequester struct {
 	eventIDMap              map[string]gomatrixserverlib.Event
 }
 
-func newBackfillRequester(db storage.Database, fsAPI federationSenderAPI.FederationSenderInternalAPI, thisServer gomatrixserverlib.ServerName, bwExtrems map[string][]string) *backfillRequester {
+func newBackfillRequester(
+	db storage.Database, fsAPI federationSenderAPI.FederationSenderInternalAPI, thisServer gomatrixserverlib.ServerName,
+	bwExtrems map[string][]string, preferServers []gomatrixserverlib.ServerName,
+) *backfillRequester {
+	preferServer := make(map[gomatrixserverlib.ServerName]bool)
+	for _, p := range preferServers {
+		preferServer[p] = true
+	}
 	return &backfillRequester{
 		db:                      db,
 		fsAPI:                   fsAPI,
@@ -234,6 +250,7 @@ func newBackfillRequester(db storage.Database, fsAPI federationSenderAPI.Federat
 		eventIDToBeforeStateIDs: make(map[string][]string),
 		eventIDMap:              make(map[string]gomatrixserverlib.Event),
 		bwExtrems:               bwExtrems,
+		preferServer:            preferServer,
 	}
 }
 
@@ -436,8 +453,16 @@ FindSuccessor:
 		if server == b.thisServer {
 			continue
 		}
-		servers = append(servers, server)
+		if b.preferServer[server] { // insert at the front
+			servers = append([]gomatrixserverlib.ServerName{server}, servers...)
+		} else { // insert at the back
+			servers = append(servers, server)
+		}
+	}
+	if len(servers) > maxBackfillServers {
+		servers = servers[:maxBackfillServers]
 	}
+
 	b.servers = servers
 	return servers
 }
diff --git a/roomserver/roomserver.go b/roomserver/roomserver.go
index 2eabf450..4c138116 100644
--- a/roomserver/roomserver.go
+++ b/roomserver/roomserver.go
@@ -41,6 +41,11 @@ func NewInternalAPI(
 ) api.RoomserverInternalAPI {
 	cfg := &base.Cfg.RoomServer
 
+	var perspectiveServerNames []gomatrixserverlib.ServerName
+	for _, kp := range base.Cfg.SigningKeyServer.KeyPerspectives {
+		perspectiveServerNames = append(perspectiveServerNames, kp.ServerName)
+	}
+
 	roomserverDB, err := storage.Open(&cfg.Database, base.Caches)
 	if err != nil {
 		logrus.WithError(err).Panicf("failed to connect to room server db")
@@ -48,6 +53,6 @@ func NewInternalAPI(
 
 	return internal.NewRoomserverAPI(
 		cfg, roomserverDB, base.KafkaProducer, string(cfg.Matrix.Kafka.TopicFor(config.TopicOutputRoomEvent)),
-		base.Caches, keyRing,
+		base.Caches, keyRing, perspectiveServerNames,
 	)
 }
diff --git a/roomserver/roomserver_test.go b/roomserver/roomserver_test.go
index 912c5852..2a03195c 100644
--- a/roomserver/roomserver_test.go
+++ b/roomserver/roomserver_test.go
@@ -238,7 +238,7 @@ func TestOutputRedactedEvent(t *testing.T) {
 	}
 }
 
-// This tests that rewriting state via KindRewrite works correctly.
+// This tests that rewriting state works correctly.
 // This creates a small room with a create/join/name state, then replays it
 // with a new room name. We expect the output events to contain the original events,
 // followed by a single OutputNewRoomEvent with RewritesState set to true with the
@@ -344,7 +344,7 @@ func TestOutputRewritesState(t *testing.T) {
 	for i := 0; i < len(rewriteEvents)-1; i++ {
 		ev := rewriteEvents[i]
 		inputEvents = append(inputEvents, api.InputRoomEvent{
-			Kind:          api.KindRewrite,
+			Kind:          api.KindOutlier,
 			Event:         ev,
 			AuthEventIDs:  ev.AuthEventIDs(),
 			HasState:      true,
diff --git a/roomserver/storage/shared/storage.go b/roomserver/storage/shared/storage.go
index f8e733ab..e96eab71 100644
--- a/roomserver/storage/shared/storage.go
+++ b/roomserver/storage/shared/storage.go
@@ -474,6 +474,32 @@ func (d *Database) StoreEvent(
 		return 0, types.StateAtEvent{}, nil, "", fmt.Errorf("d.Writer.Do: %w", err)
 	}
 
+	// We should attempt to update the previous events table with any
+	// references that this new event makes. We do this using a latest
+	// events updater because it somewhat works as a mutex, ensuring
+	// that there's a row-level lock on the latest room events (well,
+	// on Postgres at least).
+	var roomInfo *types.RoomInfo
+	var updater *LatestEventsUpdater
+	if prevEvents := event.PrevEvents(); len(prevEvents) > 0 {
+		roomInfo, err = d.RoomInfo(ctx, event.RoomID())
+		if err != nil {
+			return 0, types.StateAtEvent{}, nil, "", fmt.Errorf("d.RoomInfo: %w", err)
+		}
+		if roomInfo == nil && len(prevEvents) > 0 {
+			return 0, types.StateAtEvent{}, nil, "", fmt.Errorf("expected room %q to exist", event.RoomID())
+		}
+		updater, err = d.GetLatestEventsForUpdate(ctx, *roomInfo)
+		if err != nil {
+			return 0, types.StateAtEvent{}, nil, "", fmt.Errorf("NewLatestEventsUpdater: %w", err)
+		}
+		if err = updater.StorePreviousEvents(eventNID, prevEvents); err != nil {
+			return 0, types.StateAtEvent{}, nil, "", fmt.Errorf("updater.StorePreviousEvents: %w", err)
+		}
+		succeeded := true
+		err = sqlutil.EndTransaction(updater, &succeeded)
+	}
+
 	return roomNID, types.StateAtEvent{
 		BeforeStateSnapshotNID: stateNID,
 		StateEntry: types.StateEntry{
@@ -483,7 +509,7 @@ func (d *Database) StoreEvent(
 			},
 			EventNID: eventNID,
 		},
-	}, redactionEvent, redactedEventID, nil
+	}, redactionEvent, redactedEventID, err
 }
 
 func (d *Database) PublishRoom(ctx context.Context, roomID string, publish bool) error {
diff --git a/serverkeyapi/api/api.go b/signingkeyserver/api/api.go
index 7af62634..f053d72e 100644
--- a/serverkeyapi/api/api.go
+++ b/signingkeyserver/api/api.go
@@ -6,7 +6,7 @@ import (
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
-type ServerKeyInternalAPI interface {
+type SigningKeyServerAPI interface {
 	gomatrixserverlib.KeyDatabase
 
 	KeyRing() *gomatrixserverlib.KeyRing
diff --git a/serverkeyapi/internal/api.go b/signingkeyserver/internal/api.go
index b8a36225..54c41b52 100644
--- a/serverkeyapi/internal/api.go
+++ b/signingkeyserver/internal/api.go
@@ -7,13 +7,13 @@ import (
 	"time"
 
 	"github.com/matrix-org/dendrite/internal/config"
-	"github.com/matrix-org/dendrite/serverkeyapi/api"
+	"github.com/matrix-org/dendrite/signingkeyserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/sirupsen/logrus"
 )
 
 type ServerKeyAPI struct {
-	api.ServerKeyInternalAPI
+	api.SigningKeyServerAPI
 
 	ServerName        gomatrixserverlib.ServerName
 	ServerPublicKey   ed25519.PublicKey
@@ -98,10 +98,6 @@ func (s *ServerKeyAPI) FetchKeys(
 			// we've failed to satisfy it from local keys, database keys or from
 			// all of the fetchers. Report an error.
 			logrus.Warnf("Failed to retrieve key %q for server %q", req.KeyID, req.ServerName)
-			return results, fmt.Errorf(
-				"server key API failed to satisfy key request for server %q key ID %q",
-				req.ServerName, req.KeyID,
-			)
 		}
 	}
 
diff --git a/serverkeyapi/inthttp/client.go b/signingkeyserver/inthttp/client.go
index 39ab8c6c..71e40b8f 100644
--- a/serverkeyapi/inthttp/client.go
+++ b/signingkeyserver/inthttp/client.go
@@ -7,26 +7,26 @@ import (
 
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/httputil"
-	"github.com/matrix-org/dendrite/serverkeyapi/api"
+	"github.com/matrix-org/dendrite/signingkeyserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/opentracing/opentracing-go"
 )
 
 // HTTP paths for the internal HTTP APIs
 const (
-	ServerKeyInputPublicKeyPath = "/serverkeyapi/inputPublicKey"
-	ServerKeyQueryPublicKeyPath = "/serverkeyapi/queryPublicKey"
+	ServerKeyInputPublicKeyPath = "/signingkeyserver/inputPublicKey"
+	ServerKeyQueryPublicKeyPath = "/signingkeyserver/queryPublicKey"
 )
 
-// NewServerKeyClient creates a ServerKeyInternalAPI implemented by talking to a HTTP POST API.
+// NewSigningKeyServerClient creates a SigningKeyServerAPI implemented by talking to a HTTP POST API.
 // If httpClient is nil an error is returned
-func NewServerKeyClient(
+func NewSigningKeyServerClient(
 	serverKeyAPIURL string,
 	httpClient *http.Client,
 	cache caching.ServerKeyCache,
-) (api.ServerKeyInternalAPI, error) {
+) (api.SigningKeyServerAPI, error) {
 	if httpClient == nil {
-		return nil, errors.New("NewRoomserverInternalAPIHTTP: httpClient is <nil>")
+		return nil, errors.New("NewSigningKeyServerClient: httpClient is <nil>")
 	}
 	return &httpServerKeyInternalAPI{
 		serverKeyAPIURL: serverKeyAPIURL,
diff --git a/serverkeyapi/inthttp/server.go b/signingkeyserver/inthttp/server.go
index cd474839..d26f7380 100644
--- a/serverkeyapi/inthttp/server.go
+++ b/signingkeyserver/inthttp/server.go
@@ -7,11 +7,11 @@ import (
 	"github.com/gorilla/mux"
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/httputil"
-	"github.com/matrix-org/dendrite/serverkeyapi/api"
+	"github.com/matrix-org/dendrite/signingkeyserver/api"
 	"github.com/matrix-org/util"
 )
 
-func AddRoutes(s api.ServerKeyInternalAPI, internalAPIMux *mux.Router, cache caching.ServerKeyCache) {
+func AddRoutes(s api.SigningKeyServerAPI, internalAPIMux *mux.Router, cache caching.ServerKeyCache) {
 	internalAPIMux.Handle(ServerKeyQueryPublicKeyPath,
 		httputil.MakeInternalAPI("queryPublicKeys", func(req *http.Request) util.JSONResponse {
 			request := api.QueryPublicKeysRequest{}
diff --git a/serverkeyapi/serverkeyapi_test.go b/signingkeyserver/serverkeyapi_test.go
index 152a853e..e5578f43 100644
--- a/serverkeyapi/serverkeyapi_test.go
+++ b/signingkeyserver/serverkeyapi_test.go
@@ -1,4 +1,4 @@
-package serverkeyapi
+package signingkeyserver
 
 import (
 	"bytes"
@@ -16,18 +16,18 @@ import (
 	"github.com/matrix-org/dendrite/federationapi/routing"
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/config"
-	"github.com/matrix-org/dendrite/serverkeyapi/api"
+	"github.com/matrix-org/dendrite/signingkeyserver/api"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
 type server struct {
 	name      gomatrixserverlib.ServerName        // server name
 	validity  time.Duration                       // key validity duration from now
-	config    *config.ServerKeyAPI                // skeleton config, from TestMain
+	config    *config.SigningKeyServer            // skeleton config, from TestMain
 	fedconfig *config.FederationAPI               //
 	fedclient *gomatrixserverlib.FederationClient // uses MockRoundTripper
 	cache     *caching.Caches                     // server-specific cache
-	api       api.ServerKeyInternalAPI            // server-specific server key API
+	api       api.SigningKeyServerAPI             // server-specific server key API
 }
 
 func (s *server) renew() {
@@ -76,8 +76,8 @@ func TestMain(m *testing.M) {
 		cfg.Global.PrivateKey = testPriv
 		cfg.Global.KeyID = serverKeyID
 		cfg.Global.KeyValidityPeriod = s.validity
-		cfg.ServerKeyAPI.Database.ConnectionString = config.DataSource("file::memory:")
-		s.config = &cfg.ServerKeyAPI
+		cfg.SigningKeyServer.Database.ConnectionString = config.DataSource("file::memory:")
+		s.config = &cfg.SigningKeyServer
 		s.fedconfig = &cfg.FederationAPI
 
 		// Create a transport which redirects federation requests to
diff --git a/serverkeyapi/serverkeyapi.go b/signingkeyserver/signingkeyserver.go
index da239eb0..27b4c703 100644
--- a/serverkeyapi/serverkeyapi.go
+++ b/signingkeyserver/signingkeyserver.go
@@ -1,4 +1,4 @@
-package serverkeyapi
+package signingkeyserver
 
 import (
 	"crypto/ed25519"
@@ -7,28 +7,28 @@ import (
 	"github.com/gorilla/mux"
 	"github.com/matrix-org/dendrite/internal/caching"
 	"github.com/matrix-org/dendrite/internal/config"
-	"github.com/matrix-org/dendrite/serverkeyapi/api"
-	"github.com/matrix-org/dendrite/serverkeyapi/internal"
-	"github.com/matrix-org/dendrite/serverkeyapi/inthttp"
-	"github.com/matrix-org/dendrite/serverkeyapi/storage"
-	"github.com/matrix-org/dendrite/serverkeyapi/storage/cache"
+	"github.com/matrix-org/dendrite/signingkeyserver/api"
+	"github.com/matrix-org/dendrite/signingkeyserver/internal"
+	"github.com/matrix-org/dendrite/signingkeyserver/inthttp"
+	"github.com/matrix-org/dendrite/signingkeyserver/storage"
+	"github.com/matrix-org/dendrite/signingkeyserver/storage/cache"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/sirupsen/logrus"
 )
 
 // AddInternalRoutes registers HTTP handlers for the internal API. Invokes functions
 // on the given input API.
-func AddInternalRoutes(router *mux.Router, intAPI api.ServerKeyInternalAPI, caches *caching.Caches) {
+func AddInternalRoutes(router *mux.Router, intAPI api.SigningKeyServerAPI, caches *caching.Caches) {
 	inthttp.AddRoutes(intAPI, router, caches)
 }
 
 // NewInternalAPI returns a concerete implementation of the internal API. Callers
 // can call functions directly on the returned API or via an HTTP interface using AddInternalRoutes.
 func NewInternalAPI(
-	cfg *config.ServerKeyAPI,
+	cfg *config.SigningKeyServer,
 	fedClient gomatrixserverlib.KeyClient,
 	caches *caching.Caches,
-) api.ServerKeyInternalAPI {
+) api.SigningKeyServerAPI {
 	innerDB, err := storage.NewDatabase(
 		&cfg.Database,
 		cfg.Matrix.ServerName,
diff --git a/serverkeyapi/storage/cache/keydb.go b/signingkeyserver/storage/cache/keydb.go
index 2063dfc5..2063dfc5 100644
--- a/serverkeyapi/storage/cache/keydb.go
+++ b/signingkeyserver/storage/cache/keydb.go
diff --git a/serverkeyapi/storage/interface.go b/signingkeyserver/storage/interface.go
index 3a67ac55..3a67ac55 100644
--- a/serverkeyapi/storage/interface.go
+++ b/signingkeyserver/storage/interface.go
diff --git a/serverkeyapi/storage/keydb.go b/signingkeyserver/storage/keydb.go
index 3d3a0c30..ef1077fc 100644
--- a/serverkeyapi/storage/keydb.go
+++ b/signingkeyserver/storage/keydb.go
@@ -22,8 +22,8 @@ import (
 	"golang.org/x/crypto/ed25519"
 
 	"github.com/matrix-org/dendrite/internal/config"
-	"github.com/matrix-org/dendrite/serverkeyapi/storage/postgres"
-	"github.com/matrix-org/dendrite/serverkeyapi/storage/sqlite3"
+	"github.com/matrix-org/dendrite/signingkeyserver/storage/postgres"
+	"github.com/matrix-org/dendrite/signingkeyserver/storage/sqlite3"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
diff --git a/serverkeyapi/storage/keydb_wasm.go b/signingkeyserver/storage/keydb_wasm.go
index de66a1d6..187d9669 100644
--- a/serverkeyapi/storage/keydb_wasm.go
+++ b/signingkeyserver/storage/keydb_wasm.go
@@ -23,7 +23,7 @@ import (
 	"golang.org/x/crypto/ed25519"
 
 	"github.com/matrix-org/dendrite/internal/sqlutil"
-	"github.com/matrix-org/dendrite/serverkeyapi/storage/sqlite3"
+	"github.com/matrix-org/dendrite/signingkeyserver/storage/sqlite3"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
diff --git a/serverkeyapi/storage/postgres/keydb.go b/signingkeyserver/storage/postgres/keydb.go
index 63444085..63444085 100644
--- a/serverkeyapi/storage/postgres/keydb.go
+++ b/signingkeyserver/storage/postgres/keydb.go
diff --git a/serverkeyapi/storage/postgres/server_key_table.go b/signingkeyserver/storage/postgres/server_key_table.go
index 87f1c211..87f1c211 100644
--- a/serverkeyapi/storage/postgres/server_key_table.go
+++ b/signingkeyserver/storage/postgres/server_key_table.go
diff --git a/serverkeyapi/storage/sqlite3/keydb.go b/signingkeyserver/storage/sqlite3/keydb.go
index 0ee74bc1..0ee74bc1 100644
--- a/serverkeyapi/storage/sqlite3/keydb.go
+++ b/signingkeyserver/storage/sqlite3/keydb.go
diff --git a/serverkeyapi/storage/sqlite3/server_key_table.go b/signingkeyserver/storage/sqlite3/server_key_table.go
index 2484d636..2484d636 100644
--- a/serverkeyapi/storage/sqlite3/server_key_table.go
+++ b/signingkeyserver/storage/sqlite3/server_key_table.go
diff --git a/sytest-whitelist b/sytest-whitelist
index 9a013cbf..e0f1f311 100644
--- a/sytest-whitelist
+++ b/sytest-whitelist
@@ -473,4 +473,6 @@ Inbound federation rejects invites which include invalid JSON for room version 6
 Inbound federation rejects invite rejections which include invalid JSON for room version 6
 GET /capabilities is present and well formed for registered user 
 m.room.history_visibility == "joined" allows/forbids appropriately for Guest users
-m.room.history_visibility == "joined" allows/forbids appropriately for Real users
\ No newline at end of file
+m.room.history_visibility == "joined" allows/forbids appropriately for Real users
+Users cannot kick users who have already left a room
+A prev_batch token from incremental sync can be used in the v1 messages API