feat(agent/proto): add v2.10 PushContextState RPC

Add the ContextResource, PushContextStateRequest, and
PushContextStateResponse messages plus a new PushContextState
RPC on the Agent API. Bumps the tailnet+agent shared
CurrentVersion to 2.10 and adds the DRPCAgentClient210
interface, plus ConnectRPC210/ConnectRPC210WithRole on
codersdk/agentsdk's Client. Reserved kinds (PLUGIN, HOOK,
SUBAGENT, COMMAND) ship in the enum but are not emitted by
v1 agents.

The wire shape matches the workspace context sources RFC.
Coderd's server-side handler arrives separately.

agent/proto/agent.proto

@@ -538,6 +538,59 @@ message UpdateAppStatusRequest {
 
 message UpdateAppStatusResponse {}
 
+// ContextResource is a single resolved workspace context
+// resource (instruction file, skill meta, MCP config, or live
+// MCP server tool list) pushed from the agent to coderd as part
+// of a PushContextStateRequest snapshot.
+//
+// Reserved kinds (PLUGIN, HOOK, SUBAGENT, COMMAND) are not
+// emitted by v2.10 agents; they are forward-compatible slots
+// for the Claude Code plugin RFC.
+message ContextResource {
+	string id = 1;
+	enum Kind {
+		KIND_UNSPECIFIED = 0;
+		INSTRUCTION_FILE = 1;
+		SKILL = 2;
+		MCP_CONFIG = 3;
+		MCP_SERVER = 4;
+		PLUGIN = 5;
+		HOOK = 6;
+		SUBAGENT = 7;
+		COMMAND = 8;
+	}
+	enum Status {
+		STATUS_UNSPECIFIED = 0;
+		OK = 1;
+		OVERSIZE = 2;
+		UNREADABLE = 3;
+		INVALID = 4;
+		EXCLUDED = 5;
+	}
+	Kind kind = 2;
+	string source = 3;
+	bytes content_hash = 4;
+	bytes payload = 5;
+	optional string source_path = 6;
+	Status status = 7;
+	uint64 size_bytes = 8;
+	string error = 9;
+	string description = 10;
+}
+
+message PushContextStateRequest {
+	uint64 version = 1;
+	bytes aggregate_hash = 2;
+	repeated ContextResource resources = 3;
+	bool initial = 4;
+	uint64 schema_version = 5;
+	string snapshot_error = 6;
+}
+
+message PushContextStateResponse {
+	bool accepted = 1;
+}
+
 service Agent {
 	rpc GetManifest(GetManifestRequest) returns (Manifest);
 	rpc GetServiceBanner(GetServiceBannerRequest) returns (ServiceBanner);
@@ -557,4 +610,5 @@ service Agent {
 	rpc ListSubAgents(ListSubAgentsRequest) returns (ListSubAgentsResponse);
 	rpc ReportBoundaryLogs(ReportBoundaryLogsRequest) returns (ReportBoundaryLogsResponse);
 	rpc UpdateAppStatus(UpdateAppStatusRequest) returns (UpdateAppStatusResponse);
+	rpc PushContextState(PushContextStateRequest) returns (PushContextStateResponse);
 }

agent/proto/agent_drpc.pb.go

@@ -57,6 +57,7 @@ type DRPCAgentClient interface {
 	ListSubAgents(ctx context.Context, in *ListSubAgentsRequest) (*ListSubAgentsResponse, error)
 	ReportBoundaryLogs(ctx context.Context, in *ReportBoundaryLogsRequest) (*ReportBoundaryLogsResponse, error)
 	UpdateAppStatus(ctx context.Context, in *UpdateAppStatusRequest) (*UpdateAppStatusResponse, error)
+	PushContextState(ctx context.Context, in *PushContextStateRequest) (*PushContextStateResponse, error)
 }
 
 type drpcAgentClient struct {
@@ -231,6 +232,15 @@ func (c *drpcAgentClient) UpdateAppStatus(ctx context.Context, in *UpdateAppStat
 	return out, nil
 }
 
+func (c *drpcAgentClient) PushContextState(ctx context.Context, in *PushContextStateRequest) (*PushContextStateResponse, error) {
+	out := new(PushContextStateResponse)
+	err := c.cc.Invoke(ctx, "/coder.agent.v2.Agent/PushContextState", drpcEncoding_File_agent_proto_agent_proto{}, in, out)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 type DRPCAgentServer interface {
 	GetManifest(context.Context, *GetManifestRequest) (*Manifest, error)
 	GetServiceBanner(context.Context, *GetServiceBannerRequest) (*ServiceBanner, error)
@@ -250,6 +260,7 @@ type DRPCAgentServer interface {
 	ListSubAgents(context.Context, *ListSubAgentsRequest) (*ListSubAgentsResponse, error)
 	ReportBoundaryLogs(context.Context, *ReportBoundaryLogsRequest) (*ReportBoundaryLogsResponse, error)
 	UpdateAppStatus(context.Context, *UpdateAppStatusRequest) (*UpdateAppStatusResponse, error)
+	PushContextState(context.Context, *PushContextStateRequest) (*PushContextStateResponse, error)
 }
 
 type DRPCAgentUnimplementedServer struct{}
@@ -326,9 +337,13 @@ func (s *DRPCAgentUnimplementedServer) UpdateAppStatus(context.Context, *UpdateA
 	return nil, drpcerr.WithCode(errors.New("Unimplemented"), drpcerr.Unimplemented)
 }
 
+func (s *DRPCAgentUnimplementedServer) PushContextState(context.Context, *PushContextStateRequest) (*PushContextStateResponse, error) {
+	return nil, drpcerr.WithCode(errors.New("Unimplemented"), drpcerr.Unimplemented)
+}
+
 type DRPCAgentDescription struct{}
 
-func (DRPCAgentDescription) NumMethods() int { return 18 }
+func (DRPCAgentDescription) NumMethods() int { return 19 }
 
 func (DRPCAgentDescription) Method(n int) (string, drpc.Encoding, drpc.Receiver, interface{}, bool) {
 	switch n {
@@ -494,6 +509,15 @@ func (DRPCAgentDescription) Method(n int) (string, drpc.Encoding, drpc.Receiver,
 						in1.(*UpdateAppStatusRequest),
 					)
 			}, DRPCAgentServer.UpdateAppStatus, true
+	case 18:
+		return "/coder.agent.v2.Agent/PushContextState", drpcEncoding_File_agent_proto_agent_proto{},
+			func(srv interface{}, ctx context.Context, in1, in2 interface{}) (drpc.Message, error) {
+				return srv.(DRPCAgentServer).
+					PushContextState(
+						ctx,
+						in1.(*PushContextStateRequest),
+					)
+			}, DRPCAgentServer.PushContextState, true
 	default:
 		return "", nil, nil, nil, false
 	}
@@ -790,3 +814,19 @@ func (x *drpcAgent_UpdateAppStatusStream) SendAndClose(m *UpdateAppStatusRespons
 	}
 	return x.CloseSend()
 }
+
+type DRPCAgent_PushContextStateStream interface {
+	drpc.Stream
+	SendAndClose(*PushContextStateResponse) error
+}
+
+type drpcAgent_PushContextStateStream struct {
+	drpc.Stream
+}
+
+func (x *drpcAgent_PushContextStateStream) SendAndClose(m *PushContextStateResponse) error {
+	if err := x.MsgSend(m, drpcEncoding_File_agent_proto_agent_proto{}); err != nil {
+		return err
+	}
+	return x.CloseSend()
+}

agent/proto/agent_drpc_old.go

@@ -90,3 +90,12 @@ type DRPCAgentClient28 interface {
 type DRPCAgentClient29 interface {
 	DRPCAgentClient28
 }
+
+// DRPCAgentClient210 is the Agent API at v2.10. It adds the
+// PushContextState RPC used by the agent to ship resolved
+// workspace context snapshots (instruction files, skills, MCP
+// configs, MCP server tool lists) to coderd.
+type DRPCAgentClient210 interface {
+	DRPCAgentClient29
+	PushContextState(ctx context.Context, in *PushContextStateRequest) (*PushContextStateResponse, error)
+}

codersdk/agentsdk/agentsdk.go

@@ -336,6 +336,32 @@ func (c *Client) ConnectRPC29WithRole(ctx context.Context, role string) (
 	return proto.NewDRPCAgentClient(conn), tailnetproto.NewDRPCTailnetClient(conn), nil
 }
 
+// ConnectRPC210 returns a dRPC client to the Agent API v2.10. It is useful when
+// you want to be maximally compatible with newer Coderd Release Versions that
+// implement the PushContextState RPC.
+func (c *Client) ConnectRPC210(ctx context.Context) (
+	proto.DRPCAgentClient210, tailnetproto.DRPCTailnetClient28, error,
+) {
+	conn, err := c.connectRPCVersion(ctx, apiversion.New(2, 10), "")
+	if err != nil {
+		return nil, nil, err
+	}
+	return proto.NewDRPCAgentClient(conn), tailnetproto.NewDRPCTailnetClient(conn), nil
+}
+
+// ConnectRPC210WithRole is like ConnectRPC210 but sends an explicit role
+// query parameter to the server. Use "agent" for workspace agents to
+// enable connection monitoring.
+func (c *Client) ConnectRPC210WithRole(ctx context.Context, role string) (
+	proto.DRPCAgentClient210, tailnetproto.DRPCTailnetClient28, error,
+) {
+	conn, err := c.connectRPCVersion(ctx, apiversion.New(2, 10), role)
+	if err != nil {
+		return nil, nil, err
+	}
+	return proto.NewDRPCAgentClient(conn), tailnetproto.NewDRPCTailnetClient(conn), nil
+}
+
 // ConnectRPC connects to the workspace agent API and tailnet API.
 // It does not send a role query parameter, so the server will apply
 // its default behavior (currently: enable connection monitoring for

tailnet/proto/version.go

@@ -69,9 +69,16 @@ import (
 //   - Added session_id and confined_process fields to
 //     ReportBoundaryLogsRequest on the Agent API.
 //   - Added sequence_number field to BoundaryLog on the Agent API.
+//
+// API v2.10:
+//   - Added PushContextState RPC on the Agent API for pushing
+//     resolved workspace context snapshots (instruction files,
+//     skills, MCP configs, MCP server tool lists) from the
+//     agent to coderd. Adds ContextResource, PushContextState
+//     Request, and PushContextStateResponse messages.
 const (
 	CurrentMajor = 2
-	CurrentMinor = 9
+	CurrentMinor = 10
 )
 
 var CurrentVersion = apiversion.New(CurrentMajor, CurrentMinor)