diff --git a/api/new_chain_flusher.go b/api/new_chain_flusher.go
index 3fc38487..ddef5248 100644
--- a/api/new_chain_flusher.go
+++ b/api/new_chain_flusher.go
@@ -193,6 +193,9 @@ func (f *NewChainFlusher) flushRow(ctx context.Context, row queueRow) error {
 		return nil
 	}
 
+	// The chain ID tells core which chain this forward is meant for. A node on
+	// any other chain refuses it, so a newChainUrl pointed at the wrong chain
+	// stalls here instead of writing the backlog there.
 	req := connect.NewRequest(&v1.ForwardTransactionRequest{
 		Transaction: &v1.SignedTransaction{
 			RequestId: uuid.NewString(),
@@ -200,6 +203,7 @@ func (f *NewChainFlusher) flushRow(ctx context.Context, row queueRow) error {
 				ManageEntity: &tx,
 			},
 		},
+		ChainId: f.cfg.NewChainID,
 	})
 
 	const (
diff --git a/api/new_chain_flusher_test.go b/api/new_chain_flusher_test.go
index aa3833c1..296dfd88 100644
--- a/api/new_chain_flusher_test.go
+++ b/api/new_chain_flusher_test.go
@@ -22,11 +22,13 @@ import (
 type mockCoreService struct {
 	corev1connect.UnimplementedCoreServiceHandler
 	received []*corev1.ManageEntityLegacy
+	chainIDs []string
 	calls    atomic.Int32
 }
 
 func (m *mockCoreService) ForwardTransaction(_ context.Context, req *connect.Request[corev1.ForwardTransactionRequest]) (*connect.Response[corev1.ForwardTransactionResponse], error) {
 	m.calls.Add(1)
+	m.chainIDs = append(m.chainIDs, req.Msg.ChainId)
 	if me := req.Msg.Transaction.GetManageEntity(); me != nil {
 		m.received = append(m.received, me)
 	}
@@ -216,7 +218,7 @@ func TestNewChainFlusherTrim(t *testing.T) {
 // TestNewChainFlusherSends verifies that the flusher forwards all queued rows to
 // the new chain and marks them flushed — retaining them — on success.
 func TestNewChainFlusherSends(t *testing.T) {
-	cfg := &config.Config{} // no trim
+	cfg := &config.Config{NewChainID: "audius-mainnet-beta"} // no trim
 	f, mock := newTestFlusher(t, cfg)
 
 	block10 := int64(10)
@@ -251,6 +253,9 @@ func TestNewChainFlusherSends(t *testing.T) {
 		receivedIDs[i] = me.EntityId
 	}
 	require.ElementsMatch(t, []int64{1, 2, 3}, receivedIDs)
+
+	// Every forward names the new chain, or core refuses it.
+	require.Equal(t, []string{"audius-mainnet-beta", "audius-mainnet-beta", "audius-mainnet-beta"}, mock.chainIDs)
 }
 
 // TestNewChainFlusherTrimThenSend verifies the combined trim+flush flow:
diff --git a/api/server.go b/api/server.go
index e1adaf92..7a792f25 100644
--- a/api/server.go
+++ b/api/server.go
@@ -289,7 +289,11 @@ func NewApiServer(config config.Config) *ApiServer {
 
 	var newChainFlusher *NewChainFlusher
 	if config.NewChainFlushEnabled && config.NewChainURL != "" && writePool != nil {
-		newChainFlusher = NewNewChainFlusher(&config, writePool, logger)
+		if config.NewChainID == "" {
+			logger.Error("new chain flusher not started: newChainId is not set, and the new chain refuses forwards without a chain ID")
+		} else {
+			newChainFlusher = NewNewChainFlusher(&config, writePool, logger)
+		}
 	}
 
 	app := &ApiServer{
diff --git a/config/config.go b/config/config.go
index 2a5002bc..37c21373 100644
--- a/config/config.go
+++ b/config/config.go
@@ -89,6 +89,10 @@ type Config struct {
 	// confirmed_block < NewChainFlushFromBlock before sending — trimming rows already
 	// covered by the backfill.
 	// NewChainInsecureSkipVerify disables TLS verification for the new chain endpoint (e.g. localstack).
+	// NewChainID is the chain the flusher stamps on every ForwardTransaction.
+	// Core refuses a forward whose chain ID differs from its own, and on the
+	// new chain also one with none, so the flusher does not start without it.
+	// Defaults per environment; newChainId overrides.
 	// PlayRoutingHosts, when non-empty, are tried first when resolving a track
 	// stream URL. Plays are recorded by whichever node serves the audio, never
 	// through the relay, so this is what decides which chain a play lands on.
@@ -105,6 +109,7 @@ type Config struct {
 	PlayRoutingHosts []string
 
 	NewChainURL                string
+	NewChainID                 string
 	NewChainQueueEnabled       bool
 	NewChainFlushEnabled       bool
 	NewChainFlushFromBlock     int64
@@ -207,6 +212,7 @@ func init() {
 		Cfg.Rewards = core_config.MakeRewards(core_config.DevClaimAuthorities, core_config.DevRewardExtensions)
 		Cfg.AudiusdURL = "https://node1.oap.devnet"
 		Cfg.ChainId = "openaudio-devnet"
+		Cfg.NewChainID = "openaudio-devnet"
 		Cfg.SolanaIndexerWorkers = 1
 		Cfg.DeadNodes = []string{}
 		Cfg.BlacklistedNodes = []string{}
@@ -306,6 +312,7 @@ func init() {
 		Cfg.Rewards = core_config.MakeRewards(core_config.ProdClaimAuthorities, core_config.ProdRewardExtensions)
 		Cfg.AudiusdURL = "rpc.audius.co"
 		Cfg.ChainId = "audius-mainnet-alpha-beta"
+		Cfg.NewChainID = "audius-mainnet-beta"
 		Cfg.AudiusdChainID = core_config.ProdAcdcChainID
 		Cfg.AudiusdEntityManagerAddress = core_config.ProdAcdcAddress
 		Cfg.AudiusAppUrl = "https://audius.co"
@@ -398,6 +405,9 @@ func init() {
 
 	// Genesis migration dual-write queue
 	Cfg.NewChainURL = os.Getenv("newChainUrl")
+	if v := os.Getenv("newChainId"); v != "" {
+		Cfg.NewChainID = v
+	}
 	Cfg.NewChainQueueEnabled = os.Getenv("newChainQueueEnabled") == "true"
 	Cfg.NewChainFlushEnabled = os.Getenv("newChainFlushEnabled") == "true"
 	Cfg.NewChainInsecureSkipVerify = os.Getenv("newChainInsecureSkipVerify") == "true"
diff --git a/go.mod b/go.mod
index 2a675caa..26966b6b 100644
--- a/go.mod
+++ b/go.mod
@@ -6,7 +6,7 @@ require (
 	connectrpc.com/connect v1.18.1
 	github.com/AlecAivazis/survey/v2 v2.3.7
 	github.com/Doist/unfurlist v0.0.0-20250409100812-515f2735f8e5
-	github.com/OpenAudio/go-openaudio v1.8.2-0.20260727214803-1d9f69772e87
+	github.com/OpenAudio/go-openaudio v1.12.2-0.20261023065237-8388df0b477c
 	github.com/OpenAudio/go-openaudio/pkg/etl v1.7.1-0.20260818221412-81f4af523801
 	github.com/aquasecurity/esquery v0.2.0
 	github.com/axiomhq/axiom-go v0.23.0
diff --git a/go.sum b/go.sum
index aa6907d2..08ec98cf 100644
--- a/go.sum
+++ b/go.sum
@@ -18,8 +18,8 @@ github.com/Netflix/go-expect v0.0.0-20220104043353-73e0943537d2 h1:+vx7roKuyA63n
 github.com/Netflix/go-expect v0.0.0-20220104043353-73e0943537d2/go.mod h1:HBCaDeC1lPdgDeDbhX8XFpy1jqjK0IBG8W5K+xYqA0w=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 h1:TngWCqHvy9oXAN6lEVMRuU21PR1EtLVZJmdB18Gu3Rw=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5/go.mod h1:lmUJ/7eu/Q8D7ML55dXQrVaamCz2vxCfdQBasLZfHKk=
-github.com/OpenAudio/go-openaudio v1.8.2-0.20260727214803-1d9f69772e87 h1:HiLw4qrUkVWRADJjGsdHLlFMdJjhU5WCVNAfeKfww4s=
-github.com/OpenAudio/go-openaudio v1.8.2-0.20260727214803-1d9f69772e87/go.mod h1:lLRvUF5oWkxOyZx8rp/ecqxuMo3yzPvuvJbLSfvxguQ=
+github.com/OpenAudio/go-openaudio v1.12.2-0.20261023065237-8388df0b477c h1:saMd0Oljbar3hzuG5YA2NtYt76CbBj49EAGxevb6FTo=
+github.com/OpenAudio/go-openaudio v1.12.2-0.20261023065237-8388df0b477c/go.mod h1:lLRvUF5oWkxOyZx8rp/ecqxuMo3yzPvuvJbLSfvxguQ=
 github.com/OpenAudio/go-openaudio/pkg/etl v1.7.1-0.20260818221412-81f4af523801 h1:lYrbDv3cte0cW5AaT5oZ+u5cLPvy9pO7S05v5uwKVHQ=
 github.com/OpenAudio/go-openaudio/pkg/etl v1.7.1-0.20260818221412-81f4af523801/go.mod h1:z7X/5RziXEpASGTz7tD+P3pg4W5iCA1cKW7ogw8GShY=
 github.com/StackExchange/wmi v1.2.1 h1:VIkavFPXSjcnS+O8yTq7NI32k0R5Aj+v39y29VYDOSA=