diff --git a/.changeset/agent-threads-runtime.md b/.changeset/agent-threads-runtime.md
new file mode 100644
index 000000000..5920f46c6
--- /dev/null
+++ b/.changeset/agent-threads-runtime.md
@@ -0,0 +1,6 @@
+---
+"github.com/livekit/protocol": minor
+"@livekit/protocol": minor
+---
+
+Agent threads on the agent runtime: `Job.thread_id` and `AgentHttp.StreamPreamble.thread_id` / `thread_grant` (`AgentHttp.AgentThreadGrant`). `auth.AgentThreadGrant.ToProto` converts the claim for the preamble.
diff --git a/auth/grants.go b/auth/grants.go
index 12fe65847..12b038a31 100644
--- a/auth/grants.go
+++ b/auth/grants.go
@@ -779,6 +779,23 @@ func (s *AgentThreadGrant) Clone() *AgentThreadGrant {
 	return &clone
 }
 
+// ToProto is the grant as the node forwards it to the worker in
+// AgentHttp.StreamPreamble.thread_grant; nil stays nil.
+func (s *AgentThreadGrant) ToProto() *livekit.AgentHttp_AgentThreadGrant {
+	if s == nil {
+		return nil
+	}
+	return &livekit.AgentHttp_AgentThreadGrant{
+		Scope:     s.Scope,
+		ThreadIds: append([]string{}, s.ThreadIDs...),
+		List:      s.List,
+		Create:    s.Create,
+		Write:     s.Write,
+		Read:      s.Read,
+		Delete:    s.Delete,
+	}
+}
+
 func (s *AgentThreadGrant) MarshalLogObject(e zapcore.ObjectEncoder) error {
 	if s == nil {
 		return nil
diff --git a/livekit/agent/livekit_agent_thread.pb.go b/livekit/agent/livekit_agent_thread.pb.go
index 44f60b38b..572e810f7 100644
--- a/livekit/agent/livekit_agent_thread.pb.go
+++ b/livekit/agent/livekit_agent_thread.pb.go
@@ -21,7 +21,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.36.12
-// 	protoc        v7.36.2
+// 	protoc        v7.35.1
 // source: agent/livekit_agent_thread.proto
 
 package agent
diff --git a/livekit/livekit_agent.pb.go b/livekit/livekit_agent.pb.go
index 7ce1c942c..6ca991501 100644
--- a/livekit/livekit_agent.pb.go
+++ b/livekit/livekit_agent.pb.go
@@ -317,8 +317,10 @@ type Job struct {
 	Deployment      string            `protobuf:"bytes,11,opt,name=deployment,proto3" json:"deployment,omitempty"`
 	Attributes      map[string]string `protobuf:"bytes,12,rep,name=attributes,proto3" json:"attributes,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
 	EnableRedaction bool              `protobuf:"varint,13,opt,name=enable_redaction,json=enableRedaction,proto3" json:"enable_redaction,omitempty"`
-	unknownFields   protoimpl.UnknownFields
-	sizeCache       protoimpl.SizeCache
+	// the thread ("AT_...") this job continues; empty when dispatch made none
+	ThreadId      string `protobuf:"bytes,14,opt,name=thread_id,json=threadId,proto3" json:"thread_id,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Job) Reset() {
@@ -443,6 +445,13 @@ func (x *Job) GetEnableRedaction() bool {
 	return false
 }
 
+func (x *Job) GetThreadId() string {
+	if x != nil {
+		return x.ThreadId
+	}
+	return ""
+}
+
 type JobState struct {
 	state               protoimpl.MessageState `protogen:"open.v1"`
 	Status              JobStatus              `protobuf:"varint,1,opt,name=status,proto3,enum=livekit.JobStatus" json:"status,omitempty"`
@@ -1864,7 +1873,13 @@ type AgentHttp_StreamPreamble struct {
 	// end client address, host only
 	ClientAddr string `protobuf:"bytes,6,opt,name=client_addr,json=clientAddr,proto3" json:"client_addr,omitempty"`
 	// "http" or "https" as the end client saw it; not derivable worker-side
-	Scheme        string `protobuf:"bytes,7,opt,name=scheme,proto3" json:"scheme,omitempty"` // NEXT_ID: 8
+	Scheme string `protobuf:"bytes,7,opt,name=scheme,proto3" json:"scheme,omitempty"`
+	// the thread ("AT_...") the node resolved for this request; empty when
+	// none, and the worker resolves it from the body
+	ThreadId string `protobuf:"bytes,8,opt,name=thread_id,json=threadId,proto3" json:"thread_id,omitempty"`
+	// the verified agentThread claim of the caller's token, which never
+	// reaches the worker; the worker enforces it on the addressed thread
+	ThreadGrant   *AgentHttp_AgentThreadGrant `protobuf:"bytes,9,opt,name=thread_grant,json=threadGrant,proto3" json:"thread_grant,omitempty"` // NEXT_ID: 10
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -1948,6 +1963,114 @@ func (x *AgentHttp_StreamPreamble) GetScheme() string {
 	return ""
 }
 
+func (x *AgentHttp_StreamPreamble) GetThreadId() string {
+	if x != nil {
+		return x.ThreadId
+	}
+	return ""
+}
+
+func (x *AgentHttp_StreamPreamble) GetThreadGrant() *AgentHttp_AgentThreadGrant {
+	if x != nil {
+		return x.ThreadGrant
+	}
+	return nil
+}
+
+// auth.AgentThreadGrant on the wire: threads by scope or by id, with
+// per-action flags
+type AgentHttp_AgentThreadGrant struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Scope         string                 `protobuf:"bytes,2,opt,name=scope,proto3" json:"scope,omitempty"`
+	ThreadIds     []string               `protobuf:"bytes,3,rep,name=thread_ids,json=threadIds,proto3" json:"thread_ids,omitempty"`
+	List          bool                   `protobuf:"varint,4,opt,name=list,proto3" json:"list,omitempty"`
+	Create        bool                   `protobuf:"varint,5,opt,name=create,proto3" json:"create,omitempty"`
+	Write         bool                   `protobuf:"varint,6,opt,name=write,proto3" json:"write,omitempty"`
+	Read          bool                   `protobuf:"varint,7,opt,name=read,proto3" json:"read,omitempty"`
+	Delete        bool                   `protobuf:"varint,8,opt,name=delete,proto3" json:"delete,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *AgentHttp_AgentThreadGrant) Reset() {
+	*x = AgentHttp_AgentThreadGrant{}
+	mi := &file_livekit_agent_proto_msgTypes[22]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *AgentHttp_AgentThreadGrant) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*AgentHttp_AgentThreadGrant) ProtoMessage() {}
+
+func (x *AgentHttp_AgentThreadGrant) ProtoReflect() protoreflect.Message {
+	mi := &file_livekit_agent_proto_msgTypes[22]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use AgentHttp_AgentThreadGrant.ProtoReflect.Descriptor instead.
+func (*AgentHttp_AgentThreadGrant) Descriptor() ([]byte, []int) {
+	return file_livekit_agent_proto_rawDescGZIP(), []int{16, 3}
+}
+
+func (x *AgentHttp_AgentThreadGrant) GetScope() string {
+	if x != nil {
+		return x.Scope
+	}
+	return ""
+}
+
+func (x *AgentHttp_AgentThreadGrant) GetThreadIds() []string {
+	if x != nil {
+		return x.ThreadIds
+	}
+	return nil
+}
+
+func (x *AgentHttp_AgentThreadGrant) GetList() bool {
+	if x != nil {
+		return x.List
+	}
+	return false
+}
+
+func (x *AgentHttp_AgentThreadGrant) GetCreate() bool {
+	if x != nil {
+		return x.Create
+	}
+	return false
+}
+
+func (x *AgentHttp_AgentThreadGrant) GetWrite() bool {
+	if x != nil {
+		return x.Write
+	}
+	return false
+}
+
+func (x *AgentHttp_AgentThreadGrant) GetRead() bool {
+	if x != nil {
+		return x.Read
+	}
+	return false
+}
+
+func (x *AgentHttp_AgentThreadGrant) GetDelete() bool {
+	if x != nil {
+		return x.Delete
+	}
+	return false
+}
+
 // the server is draining: the worker should re-register elsewhere; in-flight
 // HTTP exchanges run to completion
 type AgentHttp_GoAway struct {
@@ -1959,7 +2082,7 @@ type AgentHttp_GoAway struct {
 
 func (x *AgentHttp_GoAway) Reset() {
 	*x = AgentHttp_GoAway{}
-	mi := &file_livekit_agent_proto_msgTypes[22]
+	mi := &file_livekit_agent_proto_msgTypes[23]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1971,7 +2094,7 @@ func (x *AgentHttp_GoAway) String() string {
 func (*AgentHttp_GoAway) ProtoMessage() {}
 
 func (x *AgentHttp_GoAway) ProtoReflect() protoreflect.Message {
-	mi := &file_livekit_agent_proto_msgTypes[22]
+	mi := &file_livekit_agent_proto_msgTypes[23]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1984,7 +2107,7 @@ func (x *AgentHttp_GoAway) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AgentHttp_GoAway.ProtoReflect.Descriptor instead.
 func (*AgentHttp_GoAway) Descriptor() ([]byte, []int) {
-	return file_livekit_agent_proto_rawDescGZIP(), []int{16, 3}
+	return file_livekit_agent_proto_rawDescGZIP(), []int{16, 4}
 }
 
 func (x *AgentHttp_GoAway) GetReason() string {
@@ -1998,7 +2121,7 @@ var File_livekit_agent_proto protoreflect.FileDescriptor
 
 const file_livekit_agent_proto_rawDesc = "" +
 	"\n" +
-	"\x13livekit_agent.proto\x12\alivekit\x1a\x14livekit_models.proto\x1a\x14logger/options.proto\"\xe2\x04\n" +
+	"\x13livekit_agent.proto\x12\alivekit\x1a\x14livekit_models.proto\x1a\x14logger/options.proto\"\x8c\x05\n" +
 	"\x03Job\x12\x0e\n" +
 	"\x02id\x18\x01 \x01(\tR\x02id\x12.\n" +
 	"\vdispatch_id\x18\t \x01(\tB\r\xbaP\n" +
@@ -2020,7 +2143,8 @@ const file_livekit_agent_proto_rawDesc = "" +
 	"\n" +
 	"attributes\x18\f \x03(\v2\x1c.livekit.Job.AttributesEntryB\x03\xc0P\x01R\n" +
 	"attributes\x12)\n" +
-	"\x10enable_redaction\x18\r \x01(\bR\x0fenableRedaction\x1a=\n" +
+	"\x10enable_redaction\x18\r \x01(\bR\x0fenableRedaction\x12(\n" +
+	"\tthread_id\x18\x0e \x01(\tB\v\xbaP\bthreadIDR\bthreadId\x1a=\n" +
 	"\x0fAttributesEntry\x12\x10\n" +
 	"\x03key\x18\x01 \x01(\tR\x03key\x12\x14\n" +
 	"\x05value\x18\x02 \x01(\tR\x05value:\x028\x01B\x0e\n" +
@@ -2127,7 +2251,7 @@ const file_livekit_agent_proto_rawDesc = "" +
 	"\x05token\x18\x03 \x01(\tR\x05tokenB\x06\n" +
 	"\x04_url\"1\n" +
 	"\x0eJobTermination\x12\x1f\n" +
-	"\x06job_id\x18\x01 \x01(\tB\b\xbaP\x05jobIDR\x05jobId\"\xaa\x05\n" +
+	"\x06job_id\x18\x01 \x01(\tB\b\xbaP\x05jobIDR\x05jobId\"\xee\a\n" +
 	"\tAgentHttp\x1a\x8f\x01\n" +
 	"\rAgentEndpoint\x12\x12\n" +
 	"\x04path\x18\x01 \x01(\tR\x04path\x12\x18\n" +
@@ -2135,7 +2259,7 @@ const file_livekit_agent_proto_rawDesc = "" +
 	"\x04kind\x18\x03 \x01(\x0e2$.livekit.AgentHttp.AgentEndpointKindR\x04kind\x12\x16\n" +
 	"\x06public\x18\x04 \x01(\bR\x06public\x1a?\n" +
 	"\x15AgentEndpointSettings\x12\x1a\n" +
-	"\bprotocol\x18\x01 \x01(\rR\bprotocolJ\x04\b\x02\x10\x03J\x04\b\x03\x10\x04\x1a\x8a\x02\n" +
+	"\bprotocol\x18\x01 \x01(\rR\bprotocolJ\x04\b\x02\x10\x03J\x04\b\x03\x10\x04\x1a\xfc\x02\n" +
 	"\x0eStreamPreamble\x128\n" +
 	"\x04kind\x18\x01 \x01(\x0e2$.livekit.AgentHttp.AgentEndpointKindR\x04kind\x12+\n" +
 	"\n" +
@@ -2148,7 +2272,19 @@ const file_livekit_agent_proto_rawDesc = "" +
 	"timeout_ms\x18\x05 \x01(\rR\ttimeoutMs\x12$\n" +
 	"\vclient_addr\x18\x06 \x01(\tB\x03\xc0P\x01R\n" +
 	"clientAddr\x12\x16\n" +
-	"\x06scheme\x18\a \x01(\tR\x06scheme\x1a \n" +
+	"\x06scheme\x18\a \x01(\tR\x06scheme\x12(\n" +
+	"\tthread_id\x18\b \x01(\tB\v\xbaP\bthreadIDR\bthreadId\x12F\n" +
+	"\fthread_grant\x18\t \x01(\v2#.livekit.AgentHttp.AgentThreadGrantR\vthreadGrant\x1a\xcf\x01\n" +
+	"\x10AgentThreadGrant\x12\x14\n" +
+	"\x05scope\x18\x02 \x01(\tR\x05scope\x12+\n" +
+	"\n" +
+	"thread_ids\x18\x03 \x03(\tB\f\xbaP\tthreadIDsR\tthreadIds\x12\x12\n" +
+	"\x04list\x18\x04 \x01(\bR\x04list\x12\x16\n" +
+	"\x06create\x18\x05 \x01(\bR\x06create\x12\x14\n" +
+	"\x05write\x18\x06 \x01(\bR\x05write\x12\x12\n" +
+	"\x04read\x18\a \x01(\bR\x04read\x12\x16\n" +
+	"\x06delete\x18\b \x01(\bR\x06deleteJ\x04\b\x01\x10\x02J\x04\b\t\x10\n" +
+	"\x1a \n" +
 	"\x06GoAway\x12\x16\n" +
 	"\x06reason\x18\x01 \x01(\tR\x06reason\"/\n" +
 	"\x11AgentEndpointKind\x12\f\n" +
@@ -2189,7 +2325,7 @@ func file_livekit_agent_proto_rawDescGZIP() []byte {
 }
 
 var file_livekit_agent_proto_enumTypes = make([]protoimpl.EnumInfo, 5)
-var file_livekit_agent_proto_msgTypes = make([]protoimpl.MessageInfo, 23)
+var file_livekit_agent_proto_msgTypes = make([]protoimpl.MessageInfo, 24)
 var file_livekit_agent_proto_goTypes = []any{
 	(JobType)(0),                            // 0: livekit.JobType
 	(WorkerStatus)(0),                       // 1: livekit.WorkerStatus
@@ -2218,16 +2354,17 @@ var file_livekit_agent_proto_goTypes = []any{
 	(*AgentHttp_AgentEndpoint)(nil),         // 24: livekit.AgentHttp.AgentEndpoint
 	(*AgentHttp_AgentEndpointSettings)(nil), // 25: livekit.AgentHttp.AgentEndpointSettings
 	(*AgentHttp_StreamPreamble)(nil),        // 26: livekit.AgentHttp.StreamPreamble
-	(*AgentHttp_GoAway)(nil),                // 27: livekit.AgentHttp.GoAway
-	(*Room)(nil),                            // 28: livekit.Room
-	(*ParticipantInfo)(nil),                 // 29: livekit.ParticipantInfo
-	(*ParticipantPermission)(nil),           // 30: livekit.ParticipantPermission
-	(*ServerInfo)(nil),                      // 31: livekit.ServerInfo
+	(*AgentHttp_AgentThreadGrant)(nil),      // 27: livekit.AgentHttp.AgentThreadGrant
+	(*AgentHttp_GoAway)(nil),                // 28: livekit.AgentHttp.GoAway
+	(*Room)(nil),                            // 29: livekit.Room
+	(*ParticipantInfo)(nil),                 // 30: livekit.ParticipantInfo
+	(*ParticipantPermission)(nil),           // 31: livekit.ParticipantPermission
+	(*ServerInfo)(nil),                      // 32: livekit.ServerInfo
 }
 var file_livekit_agent_proto_depIdxs = []int32{
 	0,  // 0: livekit.Job.type:type_name -> livekit.JobType
-	28, // 1: livekit.Job.room:type_name -> livekit.Room
-	29, // 2: livekit.Job.participant:type_name -> livekit.ParticipantInfo
+	29, // 1: livekit.Job.room:type_name -> livekit.Room
+	30, // 2: livekit.Job.participant:type_name -> livekit.ParticipantInfo
 	6,  // 3: livekit.Job.state:type_name -> livekit.JobState
 	22, // 4: livekit.Job.attributes:type_name -> livekit.Job.AttributesEntry
 	2,  // 5: livekit.JobState.status:type_name -> livekit.JobStatus
@@ -2243,14 +2380,14 @@ var file_livekit_agent_proto_depIdxs = []int32{
 	19, // 15: livekit.ServerMessage.assignment:type_name -> livekit.JobAssignment
 	20, // 16: livekit.ServerMessage.termination:type_name -> livekit.JobTermination
 	11, // 17: livekit.ServerMessage.pong:type_name -> livekit.WorkerPong
-	27, // 18: livekit.ServerMessage.go_away:type_name -> livekit.AgentHttp.GoAway
+	28, // 18: livekit.ServerMessage.go_away:type_name -> livekit.AgentHttp.GoAway
 	0,  // 19: livekit.SimulateJobRequest.type:type_name -> livekit.JobType
-	28, // 20: livekit.SimulateJobRequest.room:type_name -> livekit.Room
-	29, // 21: livekit.SimulateJobRequest.participant:type_name -> livekit.ParticipantInfo
+	29, // 20: livekit.SimulateJobRequest.room:type_name -> livekit.Room
+	30, // 21: livekit.SimulateJobRequest.participant:type_name -> livekit.ParticipantInfo
 	0,  // 22: livekit.RegisterWorkerRequest.type:type_name -> livekit.JobType
-	30, // 23: livekit.RegisterWorkerRequest.allowed_permissions:type_name -> livekit.ParticipantPermission
+	31, // 23: livekit.RegisterWorkerRequest.allowed_permissions:type_name -> livekit.ParticipantPermission
 	24, // 24: livekit.RegisterWorkerRequest.endpoints:type_name -> livekit.AgentHttp.AgentEndpoint
-	31, // 25: livekit.RegisterWorkerResponse.server_info:type_name -> livekit.ServerInfo
+	32, // 25: livekit.RegisterWorkerResponse.server_info:type_name -> livekit.ServerInfo
 	25, // 26: livekit.RegisterWorkerResponse.endpoint_settings:type_name -> livekit.AgentHttp.AgentEndpointSettings
 	5,  // 27: livekit.AvailabilityRequest.job:type_name -> livekit.Job
 	23, // 28: livekit.AvailabilityResponse.participant_attributes:type_name -> livekit.AvailabilityResponse.ParticipantAttributesEntry
@@ -2259,11 +2396,12 @@ var file_livekit_agent_proto_depIdxs = []int32{
 	5,  // 31: livekit.JobAssignment.job:type_name -> livekit.Job
 	3,  // 32: livekit.AgentHttp.AgentEndpoint.kind:type_name -> livekit.AgentHttp.AgentEndpointKind
 	3,  // 33: livekit.AgentHttp.StreamPreamble.kind:type_name -> livekit.AgentHttp.AgentEndpointKind
-	34, // [34:34] is the sub-list for method output_type
-	34, // [34:34] is the sub-list for method input_type
-	34, // [34:34] is the sub-list for extension type_name
-	34, // [34:34] is the sub-list for extension extendee
-	0,  // [0:34] is the sub-list for field type_name
+	27, // 34: livekit.AgentHttp.StreamPreamble.thread_grant:type_name -> livekit.AgentHttp.AgentThreadGrant
+	35, // [35:35] is the sub-list for method output_type
+	35, // [35:35] is the sub-list for method input_type
+	35, // [35:35] is the sub-list for extension type_name
+	35, // [35:35] is the sub-list for extension extendee
+	0,  // [0:35] is the sub-list for field type_name
 }
 
 func init() { file_livekit_agent_proto_init() }
@@ -2299,7 +2437,7 @@ func file_livekit_agent_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_livekit_agent_proto_rawDesc), len(file_livekit_agent_proto_rawDesc)),
 			NumEnums:      5,
-			NumMessages:   23,
+			NumMessages:   24,
 			NumExtensions: 0,
 			NumServices:   0,
 		},
diff --git a/protobufs/livekit_agent.proto b/protobufs/livekit_agent.proto
index 4747feb11..4a844f844 100644
--- a/protobufs/livekit_agent.proto
+++ b/protobufs/livekit_agent.proto
@@ -36,6 +36,8 @@ message Job {
   string deployment = 11;
   map<string, string> attributes = 12 [(logger.sensitivity) = SENSITIVITY_PII];
   bool enable_redaction = 13;
+  // the thread ("AT_...") this job continues; empty when dispatch made none
+  string thread_id = 14 [(logger.name) = "threadID"];
 }
 
 message JobState {
@@ -297,7 +299,26 @@ message AgentHttp {
     string client_addr = 6 [(logger.sensitivity) = SENSITIVITY_PII];
     // "http" or "https" as the end client saw it; not derivable worker-side
     string scheme = 7;
-    // NEXT_ID: 8
+    // the thread ("AT_...") the node resolved for this request; empty when
+    // none, and the worker resolves it from the body
+    string thread_id = 8 [(logger.name) = "threadID"];
+    // the verified agentThread claim of the caller's token, which never
+    // reaches the worker; the worker enforces it on the addressed thread
+    AgentThreadGrant thread_grant = 9;
+    // NEXT_ID: 10
+  }
+
+  // auth.AgentThreadGrant on the wire: threads by scope or by id, with
+  // per-action flags
+  message AgentThreadGrant {
+    reserved 1, 9;
+    string scope = 2;
+    repeated string thread_ids = 3 [(logger.name) = "threadIDs"];
+    bool list = 4;
+    bool create = 5;
+    bool write = 6;
+    bool read = 7;
+    bool delete = 8;
   }
 
   // why a stream was reset before any HTTP bytes flowed. This travels as the