midi-harbor/proto/midiharbor/v1/harbor.proto

// The contract between the Midi Harbor daemon and its clients.
//
// This file is the contract. Changing it is a contract change whether or not any Rust signature
// moves. The version lives in the package name: a breaking change means midiharbor.v2, never a
// reinterpreted field. Field numbers are never reused; removed ones are reserved.

syntax = "proto3";

package midiharbor.v1;

import "google/protobuf/timestamp.proto";

// Owns every endpoint and connection. Clients reach it over a Unix domain socket, or a named pipe
// on Windows.
service Harbor {
  // Identity and health.
  rpc GetServerInfo(GetServerInfoRequest) returns (ServerInfo);
  rpc GetStatus(GetStatusRequest) returns (StatusSummary);
  rpc GetCapabilities(GetCapabilitiesRequest) returns (GetCapabilitiesResponse);
  // Stops the daemon through its graceful shutdown, as SIGTERM or `service stop` does: held notes
  // are released and sessions ended. Added in 1.1 for the App Store app, whose sandbox forbids
  // signalling a daemon an earlier instance of the app started.
  rpc StopDaemon(StopDaemonRequest) returns (StopDaemonResponse);

  // Queries.
  rpc ListEndpoints(ListEndpointsRequest) returns (ListEndpointsResponse);
  rpc GetEndpoint(GetEndpointRequest) returns (Endpoint);
  rpc ListRoutes(ListRoutesRequest) returns (ListRoutesResponse);
  rpc ListPeers(ListPeersRequest) returns (ListPeersResponse);
  rpc ListEvents(ListEventsRequest) returns (ListEventsResponse);

  // Virtual ports.
  rpc CreateVirtualPort(CreateVirtualPortRequest) returns (Endpoint);
  // Changes how many MIDI In and MIDI Out connectors a virtual port has. Routes on connectors
  // it no longer has are removed, and the port is reopened.
  rpc SetVirtualPortConnectors(SetVirtualPortConnectorsRequest) returns (Endpoint);
  rpc RenameEndpoint(RenameEndpointRequest) returns (Endpoint);
  rpc DeleteVirtualPort(DeleteVirtualPortRequest) returns (DeleteVirtualPortResponse);
  rpc SetEndpointEnabled(SetEndpointEnabledRequest) returns (Endpoint);
  // Sends one note out of an endpoint, the note-on now and its note-off after length_ms, for
  // testing what listens there. The daemon sends the note-off itself, so a client that goes away
  // cannot leave the note sounding. Added in 1.2.
  rpc SendTestNote(SendTestNoteRequest) returns (SendTestNoteResponse);
  // Clears the warning that the MIDI service stopped, for every client, once someone has seen it.
  // Added in 1.2.
  rpc DismissMidiServerWarning(DismissMidiServerWarningRequest) returns (DismissMidiServerWarningResponse);

  // Network sessions.
  rpc CreateNetworkSession(CreateNetworkSessionRequest) returns (Endpoint);
  rpc ConnectPeer(ConnectPeerRequest) returns (Endpoint);
  rpc DisconnectPeer(DisconnectPeerRequest) returns (Endpoint);
  // Ends one machine's part in a network port, leaving the others connected.
  rpc DisconnectMachine(DisconnectMachineRequest) returns (Endpoint);
  rpc AddManualPeer(AddManualPeerRequest) returns (Peer);
  rpc RemovePeer(RemovePeerRequest) returns (RemovePeerResponse);
  // Switches whether a known machine is let in without asking.
  rpc SetPeerTrusted(SetPeerTrustedRequest) returns (Peer);
  rpc RespondToInvitation(RespondToInvitationRequest) returns (RespondToInvitationResponse);
  rpc SetInvitationPolicy(SetInvitationPolicyRequest) returns (Endpoint);
  // Deletes a network port, stopping what it carried first.
  rpc DeleteNetworkPort(DeleteNetworkPortRequest) returns (DeleteNetworkPortResponse);
  // Changes a network port's settings. A field left unset is left as it is.
  rpc UpdateNetworkPort(UpdateNetworkPortRequest) returns (Endpoint);

  // Physical devices are discovered, never created, so there is no create call.
  rpc ForgetPhysicalDevice(ForgetPhysicalDeviceRequest) returns (ForgetPhysicalDeviceResponse);
  rpc ResolveAmbiguousDevice(ResolveAmbiguousDeviceRequest) returns (Endpoint);

  // Bluetooth.
  rpc StartBluetoothScan(StartBluetoothScanRequest) returns (StartBluetoothScanResponse);
  rpc StopBluetoothScan(StopBluetoothScanRequest) returns (StopBluetoothScanResponse);
  rpc ConnectBluetoothDevice(ConnectBluetoothDeviceRequest) returns (Endpoint);
  rpc DisconnectBluetoothDevice(DisconnectBluetoothDeviceRequest) returns (Endpoint);
  rpc ForgetBluetoothDevice(ForgetBluetoothDeviceRequest) returns (ForgetBluetoothDeviceResponse);
  rpc SetPeripheralAdvertising(SetPeripheralAdvertisingRequest) returns (SetPeripheralAdvertisingResponse);
  // What the radio can see right now, which is not the same as what is configured. Reported
  // separately from endpoints on purpose: an entry per peripheral in range would write the
  // neighbourhood into the user's configuration file.
  rpc ListBluetoothDevices(ListBluetoothDevicesRequest) returns (ListBluetoothDevicesResponse);

  // Routes, which are the MIDI connections between endpoints.
  rpc CreateRoute(CreateRouteRequest) returns (CreateRouteResponse);
  // Changes a route's ends, connectors and whether it carries MIDI both ways, keeping whether it
  // is switched on. Its id changes when its ends do.
  rpc UpdateRoute(UpdateRouteRequest) returns (UpdateRouteResponse);
  rpc DeleteRoute(DeleteRouteRequest) returns (DeleteRouteResponse);
  rpc SetRouteEnabled(SetRouteEnabledRequest) returns (Route);

  // Configuration.
  rpc ExportConfiguration(ExportConfigurationRequest) returns (ExportConfigurationResponse);
  rpc ImportConfiguration(ImportConfigurationRequest) returns (ImportConfigurationResponse);
  rpc ReloadConfiguration(ReloadConfigurationRequest) returns (ReloadConfigurationResponse);
  rpc ExportDiagnostics(ExportDiagnosticsRequest) returns (ExportDiagnosticsResponse);
  // Reads Apple's own MIDI setup for a one-time import. Read by the daemon so that no client
  // queries CoreMIDI itself.
  rpc ReadAppleSetup(ReadAppleSetupRequest) returns (ReadAppleSetupResponse);

  // Streams. WatchState, WatchEvents and WatchInvitations are lossless; a client that falls
  // behind on them is disconnected with RESOURCE_EXHAUSTED rather than shown a diverging view.
  rpc WatchState(WatchStateRequest) returns (stream StateEvent);
  rpc WatchEvents(WatchEventsRequest) returns (stream Event);
  rpc WatchInvitations(WatchInvitationsRequest) returns (stream Invitation);

  // WatchTraffic and MonitorEndpoint are lossy by contract. HTTP/2 flow control would otherwise
  // let a stalled client apply backpressure toward the MIDI data path, which the real-time rules
  // forbid. Updates are dropped and counted instead of awaiting capacity.
  rpc WatchTraffic(WatchTrafficRequest) returns (stream TrafficUpdate);
  rpc MonitorEndpoint(MonitorEndpointRequest) returns (stream MonitoredMessage);
}

// ---------------------------------------------------------------------------
// Shared enumerations
// ---------------------------------------------------------------------------

// What kind of thing an endpoint is.
enum EndpointKind {
  ENDPOINT_KIND_UNSPECIFIED = 0;
  ENDPOINT_KIND_VIRTUAL_PORT = 1;
  ENDPOINT_KIND_PHYSICAL_DEVICE = 2;
  ENDPOINT_KIND_NETWORK_SESSION = 3;
  ENDPOINT_KIND_BLUETOOTH_DEVICE = 4;
}

// Which way MIDI can travel through an endpoint.
enum Direction {
  DIRECTION_UNSPECIFIED = 0;
  DIRECTION_INPUT = 1;
  DIRECTION_OUTPUT = 2;
  DIRECTION_BIDIRECTIONAL = 3;
}

// Where a connection sits in its lifecycle.
enum ConnectionPhase {
  CONNECTION_PHASE_UNSPECIFIED = 0;
  // Switched off by the user. The only phase that stays put on its own.
  CONNECTION_PHASE_DISABLED = 1;
  CONNECTION_PHASE_DISCONNECTED = 2;
  CONNECTION_PHASE_CONNECTING = 3;
  CONNECTION_PHASE_CONNECTED = 4;
  // Down for a reason the user cannot act on, waiting out a backoff delay.
  CONNECTION_PHASE_RETRYING = 5;
  // Down for a reason the user can act on. Still retried, and re-evaluated every attempt.
  CONNECTION_PHASE_UNAVAILABLE = 6;
}

// How a session treats incoming invitations.
enum InvitationPolicy {
  INVITATION_POLICY_UNSPECIFIED = 0;
  INVITATION_POLICY_PROMPT = 1;
  INVITATION_POLICY_ACCEPT_KNOWN = 2;
  INVITATION_POLICY_ACCEPT_ALL = 3;
  INVITATION_POLICY_REJECT_ALL = 4;
}

// Whether a route can currently deliver.
enum RouteValidity {
  ROUTE_VALIDITY_UNSPECIFIED = 0;
  ROUTE_VALIDITY_VALID = 1;
  // One or both endpoints are missing; the route is kept so it can resume when they return.
  ROUTE_VALIDITY_BROKEN = 2;
  // The route takes part in a cycle. Creation is still allowed, but the user is warned.
  ROUTE_VALIDITY_LOOP_DETECTED = 3;
  // Both endpoints exist, but one is not running, so nothing can pass. The configuration is
  // intact and delivery resumes when it is available again.
  ROUTE_VALIDITY_SUSPENDED = 4;
}

// How confidently stored hardware was matched to something attached.
enum MatchConfidence {
  MATCH_CONFIDENCE_UNSPECIFIED = 0;
  MATCH_CONFIDENCE_NONE = 1;
  // Never rebinds a route on its own: binding the wrong hardware is worse than asking.
  MATCH_CONFIDENCE_AMBIGUOUS = 2;
  MATCH_CONFIDENCE_PROBABLE = 3;
  MATCH_CONFIDENCE_EXACT = 4;
}

// How much attention an event deserves.
enum Severity {
  SEVERITY_UNSPECIFIED = 0;
  SEVERITY_INFO = 1;
  SEVERITY_WARNING = 2;
  SEVERITY_ERROR = 3;
}

// ---------------------------------------------------------------------------
// Core messages
// ---------------------------------------------------------------------------

// Identifies which build and contract version the daemon serves.
message ServerInfo {
  string daemon_version = 1;
  uint32 protocol_major = 2;
  uint32 protocol_minor = 3;
  google.protobuf.Timestamp started_at = 4;
  string config_path = 5;
  string socket_path = 6;
  // Identifies the daemon's build apart from every other build, the same version included.
  // Empty from a daemon older than protocol 1.3.
  string build_id = 7;
}

// Why a connection is not usable. The slug is the stable value clients switch on.
message FailureReason {
  // Stable machine-readable slug, such as name_conflict or permission_denied.
  string code = 1;
  // Human-readable description. May change between releases; never switch on it.
  string message = 2;
  // What the user can do about it, when there is anything.
  string guidance = 3;
  // Whether clearing this requires the user to act.
  bool needs_user_action = 4;
}

// The lifecycle position of one endpoint, with the history needed to explain it.
message ConnectionState {
  ConnectionPhase phase = 1;
  google.protobuf.Timestamp since = 2;
  // Retained after recovery, so a user can see what happened while they were not watching.
  FailureReason last_error = 3;
  uint32 attempt = 4;
  google.protobuf.Timestamp next_retry = 5;
  // Set while the link keeps connecting and dropping again within seconds. Its retries are
  // spaced out regardless; this says why it keeps going quiet.
  bool unstable = 6;
  // Set while a network session has no network to reach its peer by: the machine has no route
  // there at all, as opposed to a peer that is not answering.
  bool waiting_for_network = 7;
}

// Live traffic counts for one endpoint or route.
message TrafficCounters {
  uint64 messages_sent = 1;
  uint64 messages_received = 2;
  uint64 bytes_sent = 3;
  uint64 bytes_received = 4;
  // Lost by the network, detected as a gap in sequence numbers.
  uint64 messages_lost = 5;
  // Rebuilt from the recovery journal.
  uint64 messages_recovered = 6;
  // Discarded by our own backpressure, kept distinct from network loss on purpose.
  uint64 messages_dropped = 7;
  google.protobuf.Timestamp last_activity = 8;
  // Bluetooth MIDI packets from the device that could not be decoded and were discarded whole.
  uint64 packets_malformed = 9;
  // When a message was last received, and last sent, apart because last_activity cannot say
  // which way traffic went.
  google.protobuf.Timestamp last_received = 10;
  google.protobuf.Timestamp last_sent = 11;
}

// The values used to recognise one piece of hardware again after it is replugged.
message DeviceFingerprint {
  optional uint32 unique_id = 1;
  optional string usb_serial = 2;
  optional string manufacturer = 3;
  optional string model = 4;
  // Always present, never sufficient on its own.
  string name = 5;
  optional string topology_path = 6;
}

message VirtualPortDetail {
  // The first MIDI Out connector's platform identifier.
  optional uint32 platform_unique_id = 1;
  // MIDI In connectors, which other applications send to: one to sixteen.
  uint32 inputs = 2;
  // MIDI Out connectors, which other applications receive from: one to sixteen.
  uint32 outputs = 3;
}

message PhysicalDeviceDetail {
  DeviceFingerprint fingerprint = 1;
  bool present = 2;
  MatchConfidence confidence = 3;
  // Names the application holding the device exclusively, when one does.
  optional string claimed_by = 4;
  // Another application's port, or one macOS makes itself such as an IAC bus or an Apple
  // network session, rather than hardware.
  bool software = 5;
}

message NetworkSessionDetail {
  string local_name = 1;
  // The data port is always this plus one.
  uint32 control_port = 2;
  optional string peer_id = 3;
  InvitationPolicy invitation_policy = 4;
  // Time since the last successful clock exchange, the authoritative liveness signal.
  optional uint64 last_sync_age_ms = 5;
  optional int64 clock_offset_ns = 6;
  optional uint64 round_trip_us = 7;
  // Machines carried beside the peer, having invited the session while it already had one, by
  // the name each advertises or its address.
  repeated string guests = 8;
  // Whether other applications on this computer see it as a MIDI port of its name, joined to it
  // both ways.
  bool automatic_port = 9;
  // Every machine taking part, the peer first.
  repeated NetworkMachine machines = 10;
  // The automatic port's traffic, while it is open: received is what other applications sent
  // it, sent is what it passed on to them.
  TrafficCounters automatic_port_counters = 11;
}

// One machine taking part in a network port.
message NetworkMachine {
  // Its control address, host:port.
  string address = 1;
  // The name it advertises, once known.
  optional string name = 2;
  // Whether this side connected to it, rather than it to this side.
  bool invited = 3;
  // Whether it has finished joining and is carrying MIDI.
  bool joined = 4;
  // The most recent round trip to it, once measured.
  optional uint64 round_trip_us = 5;
}

message BluetoothDeviceDetail {
  string address = 1;
  bool paired = 2;
  optional int32 rssi = 3;
  // True when this device connected to us rather than us connecting to it.
  bool peripheral_role = 4;
}

// Anything MIDI can flow to or from.
message Endpoint {
  string id = 1;
  string name = 2;
  EndpointKind kind = 3;
  bool enabled = 4;
  Direction direction = 5;
  ConnectionState state = 6;
  TrafficCounters counters = 7;

  oneof detail {
    VirtualPortDetail virtual_port = 8;
    PhysicalDeviceDetail physical_device = 9;
    NetworkSessionDetail network_session = 10;
    BluetoothDeviceDetail bluetooth_device = 11;
  }
}

// A MIDI connection between two endpoints.
message Route {
  string id = 1;
  string from_name = 2;
  string to_name = 3;
  optional string from_id = 4;
  optional string to_id = 5;
  bool enabled = 6;
  RouteValidity validity = 7;
  // Populated when validity is BROKEN: the endpoint names that matched nothing.
  repeated string missing = 8;
  // Populated when validity is LOOP_DETECTED: the route ids forming the cycle.
  repeated string cycle = 9;
  TrafficCounters counters = 10;
  // Populated when validity is SUSPENDED: the endpoints that exist but are not running.
  repeated string waiting_on = 11;
  // Which of the source's MIDI In connectors the route starts from, counting from one.
  uint32 from_connector = 12;
  // Which of the destination's MIDI Out connectors the route ends at, counting from one.
  uint32 to_connector = 13;
  // Whether it also carries MIDI back, from the destination's MIDI In to_connector to the
  // source's MIDI Out from_connector.
  bool both_ways = 14;
}

// A discovered or manually added remote party.
message Peer {
  string id = 1;
  string advertised_name = 2;
  repeated string addresses = 3;
  bool discovered = 4;
  bool trusted = 5;
  google.protobuf.Timestamp last_seen = 6;
}

// Whether one capability is available, and why not when it is not.
message Capability {
  // Readable, such as "bluetooth connections", and may be reworded.
  string name = 1;
  bool available = 2;
  string reason = 3;
  // Stable, such as "bluetooth_central", for clients choosing what to show.
  string id = 4;
}

// A timestamped record of something that happened.
message Event {
  uint64 id = 1;
  google.protobuf.Timestamp at = 2;
  optional string endpoint_id = 3;
  optional string route_id = 4;
  Severity severity = 5;
  // Stable machine-readable name, such as endpoint_state_changed.
  string kind = 6;
  string detail = 7;
}

// A peer asking to establish a session with this machine.
message Invitation {
  string invitation_id = 1;
  string session_endpoint_id = 2;
  string peer_name = 3;
  string peer_address = 4;
  google.protobuf.Timestamp received_at = 5;
  bool peer_known = 6;
}

// ---------------------------------------------------------------------------
// Requests and responses
// ---------------------------------------------------------------------------

message GetServerInfoRequest {}

message GetStatusRequest {}

message StopDaemonRequest {}

message StopDaemonResponse {}

message StatusSummary {
  ServerInfo server = 1;
  uint32 endpoint_count = 2;
  uint32 connected_count = 3;
  uint32 route_count = 4;
  uint32 broken_route_count = 5;
  // When the platform's MIDI service was found gone, while the warning about it stands: set by the
  // daemon that replaced the one that lost it, and cleared by DismissMidiServerWarning. Other
  // applications that were using MIDI may have lost it with the service, which the daemon cannot
  // see or mend.
  google.protobuf.Timestamp midi_server_replaced_at = 6;
}

message GetCapabilitiesRequest {}

message GetCapabilitiesResponse {
  repeated Capability capabilities = 1;
}

message ListEndpointsRequest {
  // Restricts the listing to one kind when set.
  optional EndpointKind kind = 1;
  // Includes remembered hardware that is currently unplugged.
  bool include_absent = 2;
}

message ListEndpointsResponse {
  repeated Endpoint endpoints = 1;
}

message GetEndpointRequest {
  string id = 1;
}

message ListRoutesRequest {
  bool only_broken = 1;
}

message ListRoutesResponse {
  repeated Route routes = 1;
}

message ListPeersRequest {}

message ListPeersResponse {
  repeated Peer peers = 1;
}

message ListEventsRequest {
  // Returns only events newer than this identifier.
  optional uint64 after_id = 1;
  uint32 limit = 2;
  optional string endpoint_id = 3;
}

message ListEventsResponse {
  repeated Event events = 1;
}

message CreateVirtualPortRequest {
  string name = 1;
  // Not used: a virtual port always carries MIDI both ways, as MIDI In and MIDI Out connectors.
  Direction direction = 2;
  // MIDI In connectors, one to sixteen. Zero means one.
  uint32 inputs = 3;
  // MIDI Out connectors, one to sixteen. Zero means one.
  uint32 outputs = 4;
}

message SetVirtualPortConnectorsRequest {
  // The port, by name or identifier.
  string id = 1;
  // MIDI In connectors, one to sixteen.
  uint32 inputs = 2;
  // MIDI Out connectors, one to sixteen.
  uint32 outputs = 3;
}

message RenameEndpointRequest {
  string id = 1;
  string new_name = 2;
  // Without this, the call fails FAILED_PRECONDITION and reports which applications may need to
  // reselect the port. Renaming also rewrites every route that names this endpoint.
  bool confirm = 3;
}

message DeleteVirtualPortRequest {
  string id = 1;
}

message DeleteNetworkPortRequest {
  // The network port, by name or identifier.
  string id = 1;
}

message DeleteNetworkPortResponse {
  // Routes that referenced the deleted network port and are now broken.
  repeated string orphaned_routes = 1;
}

message DeleteVirtualPortResponse {
  // Routes that referenced the deleted port and are now broken.
  repeated string orphaned_routes = 1;
}

message SetEndpointEnabledRequest {
  string id = 1;
  bool enabled = 2;
}

message SendTestNoteRequest {
  // The endpoint to send out of, by name or identifier. It must be one a route could send to.
  string endpoint_id = 1;
  // 1 to 16.
  uint32 channel = 2;
  // 0 to 127; 60 is middle C.
  uint32 note = 3;
  // 1 to 127. Zero would be read as a note-off.
  uint32 velocity = 4;
  // How long the note sounds, 1 to 10000 milliseconds; 500 when unset.
  optional uint32 length_ms = 5;
}

message SendTestNoteResponse {}

message DismissMidiServerWarningRequest {}

message DismissMidiServerWarningResponse {
  // Whether there was a warning to dismiss.
  bool dismissed = 1;
}

message CreateNetworkSessionRequest {
  string name = 1;
  // Zero asks the daemon to choose. The data port is always control_port plus one.
  uint32 control_port = 2;
  InvitationPolicy invitation_policy = 3;
  // Whether other applications on this computer see it as a MIDI port of its name. Unset means
  // yes.
  optional bool automatic_port = 4;
  // The name other machines see it by, its Bonjour name. Unset means its name.
  optional string local_name = 5;
}

message UpdateNetworkPortRequest {
  // The network port, by name or identifier.
  string id = 1;
  optional bool automatic_port = 2;
  // The name other machines see it by. Machines already connected keep the name they were told.
  optional string local_name = 3;
  // The UDP port to listen on, zero to let the system choose. The network port restarts on it:
  // a machine it connected to is connected to again, and one that connected to it needs the new
  // port.
  optional uint32 control_port = 4;
  optional InvitationPolicy invitation_policy = 5;
}

message ConnectPeerRequest {
  string session_endpoint_id = 1;
  string peer_id = 2;
  // Carry the machine beside those already connected, rather than in place of the peer. It is
  // remembered and reconnected as the peer is, until it is disconnected.
  bool alongside = 3;
}

message DisconnectMachineRequest {
  string session_endpoint_id = 1;
  // The machine's address, as NetworkMachine reports it.
  string address = 2;
}

message DisconnectPeerRequest {
  string session_endpoint_id = 1;
}

message AddManualPeerRequest {
  string address = 1;
  uint32 port = 2;
  optional string name = 3;
  // Whether it is let in without asking. Unset means yes.
  optional bool trusted = 4;
}

message SetPeerTrustedRequest {
  // The machine, by identifier, name or address.
  string peer_id = 1;
  bool trusted = 2;
}

message RemovePeerRequest {
  string peer_id = 1;
}

message RemovePeerResponse {}

message RespondToInvitationRequest {
  string invitation_id = 1;
  bool accept = 2;
  // Remembers the peer as trusted, so future invitations are accepted without asking.
  bool always = 3;
}

message RespondToInvitationResponse {}

message SetInvitationPolicyRequest {
  string session_endpoint_id = 1;
  InvitationPolicy policy = 2;
}

message ForgetPhysicalDeviceRequest {
  string id = 1;
}

message ForgetPhysicalDeviceResponse {
  repeated string orphaned_routes = 1;
  // Set when the hardware is still plugged in, so it has been listed again as something never
  // seen before rather than disappearing.
  bool still_attached = 2;
}

message ResolveAmbiguousDeviceRequest {
  string id = 1;
  // The attached hardware the user chose for this stored entry.
  DeviceFingerprint chosen = 2;
}

message StartBluetoothScanRequest {
  uint32 duration_seconds = 1;
}

message StartBluetoothScanResponse {}

message StopBluetoothScanRequest {}

message StopBluetoothScanResponse {}

message ConnectBluetoothDeviceRequest {
  string address = 1;
}

message DisconnectBluetoothDeviceRequest {
  string id = 1;
}

message ForgetBluetoothDeviceRequest {
  string id = 1;
}

message ForgetBluetoothDeviceResponse {}

message SetPeripheralAdvertisingRequest {
  bool enabled = 1;
  optional string name = 2;
}

message SetPeripheralAdvertisingResponse {
  bool advertising = 1;
  // The name the advertisement was asked to carry, when advertising.
  string name = 2;
  // Whether the platform actually sends that name. macOS has room for five bytes of name beside
  // the MIDI service and drops a longer one, so devices show the computer's own name instead.
  bool name_sent = 3;
}

message ListBluetoothDevicesRequest {}

message ListBluetoothDevicesResponse {
  repeated DiscoveredBluetoothDevice devices = 1;
}

// A peripheral the radio can currently hear.
message DiscoveredBluetoothDevice {
  // The platform's own name for it, which is a hardware address on Linux and an opaque
  // identifier on macOS. Never parsed by a client.
  string address = 1;
  optional string name = 2;
  optional int32 rssi = 3;
  bool paired = 4;
  // Set when this device already has a configured endpoint.
  optional string endpoint_id = 5;
}

message CreateRouteRequest {
  // Endpoint name or identifier. Names are accepted because that is what the stored
  // configuration uses and what a person types.
  string from = 1;
  string to = 2;
  // Which of the source's MIDI In connectors, counting from one. Zero means the first.
  uint32 from_connector = 3;
  // Which of the destination's MIDI Out connectors, counting from one. Zero means the first.
  uint32 to_connector = 4;
  // Whether it also carries MIDI back through the same connector numbers the other way round.
  bool both_ways = 5;
}

message UpdateRouteRequest {
  // The route to change.
  string id = 1;
  // Endpoint name or identifier, as for CreateRoute.
  string from = 2;
  string to = 3;
  uint32 from_connector = 4;
  uint32 to_connector = 5;
  bool both_ways = 6;
}

message UpdateRouteResponse {
  Route route = 1;
  // Populated when the route now completes a cycle. The change still succeeds, per FR-033.
  repeated string loop_warning = 2;
}

message CreateRouteResponse {
  Route route = 1;
  // Populated when the new route completes a cycle. Creation still succeeds, per FR-033.
  repeated string loop_warning = 2;
}

message DeleteRouteRequest {
  string id = 1;
}

message DeleteRouteResponse {}

message SetRouteEnabledRequest {
  string id = 1;
  bool enabled = 2;
}

message ExportConfigurationRequest {}

message ExportConfigurationResponse {
  // The YAML document, exactly as it would be written to disk.
  string yaml = 1;
}

message ImportConfigurationRequest {
  string yaml = 1;
  // Replaces the whole setup rather than merging into it.
  bool replace = 2;
}

message ImportConfigurationResponse {
  uint32 endpoints_added = 1;
  uint32 routes_added = 2;
  // Connections that were disturbed because their configuration actually changed, by name.
  repeated string restarted_endpoints = 3;
  // Endpoints a replacing import removed, by name. A merge never removes anything.
  repeated string removed_endpoints = 4;
  // Settings that were accepted but only take effect when the daemon next starts.
  repeated string pending_restart = 5;
}

message ReloadConfigurationRequest {}

message ReloadConfigurationResponse {
  // Connections that were disturbed because their configuration actually changed, by name.
  repeated string restarted_endpoints = 1;
  // Never set. A reload refuses a document it cannot read and leaves everything running, rather
  // than preserving the file and starting from defaults as the daemon does at startup.
  optional string repaired_from = 2;
  repeated string added_endpoints = 3;
  repeated string removed_endpoints = 4;
  uint32 routes_added = 5;
  // Settings that were accepted but only take effect when the daemon next starts.
  repeated string pending_restart = 6;
}

message ReadAppleSetupRequest {}

message ReadAppleSetupResponse {
  // False on a platform with no Apple MIDI setup, when the other fields are empty.
  bool available = 1;
  // Whether the IAC Driver is switched on, so its buses are visible to applications now.
  bool iac_online = 2;
  // The IAC Driver's bus names.
  repeated string buses = 3;
  // The network sessions configured in Audio MIDI Setup.
  repeated string sessions = 4;
}

message ExportDiagnosticsRequest {
  bool include_message_log = 1;
}

message ExportDiagnosticsResponse {
  string report = 1;
}

message WatchStateRequest {}

// Something changed about the shape or state of the system.
message StateEvent {
  oneof change {
    Endpoint endpoint_changed = 1;
    Endpoint endpoint_added = 2;
    string endpoint_removed = 3;
    Route route_changed = 4;
    string route_removed = 5;
    GetCapabilitiesResponse capabilities_changed = 6;
  }
}

message WatchEventsRequest {
  optional uint64 after_id = 1;
}

message WatchInvitationsRequest {}

message WatchTrafficRequest {
  // Restricts updates to these endpoints. Empty means all of them.
  repeated string endpoint_ids = 1;
}

// Coalesced counters, emitted at most every 250ms per endpoint and never per message.
message TrafficUpdate {
  string endpoint_id = 1;
  TrafficCounters counters = 2;
  // Updates discarded for this subscriber since the last message, because this stream is lossy
  // by contract rather than applying backpressure toward the data path.
  uint64 dropped = 3;
}

message MonitorEndpointRequest {
  string endpoint_id = 1;
}

// One decoded MIDI message observed on an endpoint.
message MonitoredMessage {
  google.protobuf.Timestamp at = 1;
  // Raw bytes, for the hex view.
  bytes data = 2;
  // Human-readable decoding, such as "note on ch1 C4 vel100".
  string decoded = 3;
  bool outbound = 4;
  // Messages discarded for this subscriber since the last one delivered.
  uint64 dropped = 5;
}