Migrate from A2A v0 to v1 (part 1)

go/adk/pkg/tools/skills_test.go

@@ -21,8 +21,12 @@ func TestResolveReadPath_AllowsSymlinkedSkillsDirectory(t *testing.T) {
 	if err != nil {
 		t.Fatalf("resolveReadPath() error = %v", err)
 	}
-	if resolved != skillFile {
-		t.Fatalf("resolveReadPath() = %q, want %q", resolved, skillFile)
+	want, err := filepath.EvalSymlinks(skillFile)
+	if err != nil {
+		t.Fatalf("EvalSymlinks() error = %v", err)
+	}
+	if resolved != want {
+		t.Fatalf("resolveReadPath() = %q, want %q", resolved, want)
 	}
 }
 

go/api/config/crd/bases/kagent.dev_agents.yaml

@@ -7696,35 +7696,36 @@ spec:
                               description: Examples are optional usage examples.
                               items:
                                 type: string
+                              maxItems: 20
                               type: array
                             id:
                               description: ID is the unique identifier for the skill.
                               type: string
                             inputModes:
-                              description: InputModes are the supported input data
-                                modes/types.
+                              description: InputModes are the supported input MIME
+                                types for this skill, overriding the agent's defaults.
                               items:
                                 type: string
                               type: array
                             name:
                               description: Name is the human-readable name of the
                                 skill.
+                              minLength: 1
                               type: string
                             outputModes:
-                              description: OutputModes are the supported output data
-                                modes/types.
+                              description: OutputModes are the supported output MIME
+                                types for this skill, overriding the agent's defaults.
                               items:
                                 type: string
                               type: array
                             tags:
                               description: Tags are optional tags for categorization.
                               items:
                                 type: string
+                              maxItems: 20
                               type: array
                           required:
-                          - id
                           - name
-                          - tags
                           type: object
                         minItems: 1
                         type: array

go/api/config/crd/bases/kagent.dev_sandboxagents.yaml

@@ -5354,35 +5354,36 @@ spec:
                               description: Examples are optional usage examples.
                               items:
                                 type: string
+                              maxItems: 20
                               type: array
                             id:
                               description: ID is the unique identifier for the skill.
                               type: string
                             inputModes:
-                              description: InputModes are the supported input data
-                                modes/types.
+                              description: InputModes are the supported input MIME
+                                types for this skill, overriding the agent's defaults.
                               items:
                                 type: string
                               type: array
                             name:
                               description: Name is the human-readable name of the
                                 skill.
+                              minLength: 1
                               type: string
                             outputModes:
-                              description: OutputModes are the supported output data
-                                modes/types.
+                              description: OutputModes are the supported output MIME
+                                types for this skill, overriding the agent's defaults.
                               items:
                                 type: string
                               type: array
                             tags:
                               description: Tags are optional tags for categorization.
                               items:
                                 type: string
+                              maxItems: 20
                               type: array
                           required:
-                          - id
                           - name
-                          - tags
                           type: object
                         minItems: 1
                         type: array

go/api/database/client.go

@@ -4,9 +4,9 @@ import (
 	"context"
 	"time"
 
+	a2a "github.com/a2aproject/a2a-go/v2/a2a"
 	"github.com/kagent-dev/kagent/go/api/v1alpha2"
 	"github.com/pgvector/pgvector-go"
-	"trpc.group/trpc-go/trpc-a2a-go/protocol"
 )
 
 type QueryOptions struct {
@@ -24,8 +24,8 @@ type Client interface {
 	StoreFeedback(ctx context.Context, feedback *Feedback) error
 	StoreSession(ctx context.Context, session *Session) error
 	StoreAgent(ctx context.Context, agent *Agent) error
-	StoreTask(ctx context.Context, task *protocol.Task) error
-	StorePushNotification(ctx context.Context, config *protocol.TaskPushNotificationConfig) error
+	StoreTask(ctx context.Context, task *a2a.Task) error
+	StorePushNotification(ctx context.Context, config *a2a.PushConfig) error
 	StoreToolServer(ctx context.Context, toolServer *ToolServer) (*ToolServer, error)
 	StoreEvents(ctx context.Context, messages ...*Event) error
 
@@ -40,23 +40,23 @@ type Client interface {
 	// Get methods
 	GetSession(ctx context.Context, sessionID string, userID string) (*Session, error)
 	GetAgent(ctx context.Context, name string) (*Agent, error)
-	GetTask(ctx context.Context, id string) (*protocol.Task, error)
+	GetTask(ctx context.Context, id string) (*a2a.Task, error)
 	GetTool(ctx context.Context, name string) (*Tool, error)
 	GetToolServer(ctx context.Context, name string) (*ToolServer, error)
-	GetPushNotification(ctx context.Context, taskID string, configID string) (*protocol.TaskPushNotificationConfig, error)
+	GetPushNotification(ctx context.Context, taskID string, configID string) (*a2a.PushConfig, error)
 
 	// List methods
 	ListTools(ctx context.Context) ([]Tool, error)
 	ListFeedback(ctx context.Context, userID string) ([]Feedback, error)
-	ListTasksForSession(ctx context.Context, sessionID string) ([]*protocol.Task, error)
+	ListTasksForSession(ctx context.Context, sessionID string) ([]*a2a.Task, error)
 	ListSessions(ctx context.Context, userID string) ([]Session, error)
 	ListSessionsForAgent(ctx context.Context, agentID string, userID string) ([]Session, error)
 	ListSessionsForAgentAllUsers(ctx context.Context, agentID string) ([]Session, error)
 	ListAgents(ctx context.Context) ([]Agent, error)
 	ListToolServers(ctx context.Context) ([]ToolServer, error)
 	ListToolsForServer(ctx context.Context, serverName string, groupKind string) ([]Tool, error)
 	ListEventsForSession(ctx context.Context, sessionID, userID string, options QueryOptions) ([]*Event, error)
-	ListPushNotifications(ctx context.Context, taskID string) ([]*protocol.TaskPushNotificationConfig, error)
+	ListPushNotifications(ctx context.Context, taskID string) ([]*a2a.PushConfig, error)
 
 	// Helper methods
 	RefreshToolsForServer(ctx context.Context, serverName string, groupKind string, tools ...*v1alpha2.MCPTool) error

go/api/database/models.go

@@ -4,10 +4,10 @@ import (
 	"encoding/json"
 	"time"
 
+	a2a "github.com/a2aproject/a2a-go/v2/a2a"
 	"github.com/kagent-dev/kagent/go/api/adk"
 	"github.com/kagent-dev/kagent/go/api/v1alpha2"
 	"github.com/pgvector/pgvector-go"
-	"trpc.group/trpc-go/trpc-a2a-go/protocol"
 )
 
 type Agent struct {
@@ -32,16 +32,16 @@ type Event struct {
 	Data string `json:"data"` // JSON-serialized protocol.Message
 }
 
-func (m *Event) Parse() (protocol.Message, error) {
-	var data protocol.Message
+func (m *Event) Parse() (a2a.Message, error) {
+	var data a2a.Message
 	if err := json.Unmarshal([]byte(m.Data), &data); err != nil {
-		return protocol.Message{}, err
+		return a2a.Message{}, err
 	}
 	return data, nil
 }
 
-func ParseMessages(messages []Event) ([]*protocol.Message, error) {
-	result := make([]*protocol.Message, 0, len(messages))
+func ParseMessages(messages []Event) ([]*a2a.Message, error) {
+	result := make([]*a2a.Message, 0, len(messages))
 	for _, message := range messages {
 		parsed, err := message.Parse()
 		if err != nil {
@@ -77,24 +77,25 @@ type Session struct {
 }
 
 type Task struct {
-	ID        string     `json:"id"`
-	CreatedAt time.Time  `json:"created_at"`
-	UpdatedAt time.Time  `json:"updated_at"`
-	DeletedAt *time.Time `json:"deleted_at,omitempty"`
-	Data      string     `json:"data"` // JSON-serialized task data
-	SessionID string     `json:"session_id"`
+	ID              string     `json:"id"`
+	CreatedAt       time.Time  `json:"created_at"`
+	UpdatedAt       time.Time  `json:"updated_at"`
+	DeletedAt       *time.Time `json:"deleted_at,omitempty"`
+	Data            string     `json:"data"` // JSON-serialized task data
+	ProtocolVersion *string    `json:"protocol_version,omitempty"`
+	SessionID       string     `json:"session_id"`
 }
 
-func (t *Task) Parse() (protocol.Task, error) {
-	var data protocol.Task
+func (t *Task) Parse() (a2a.Task, error) {
+	var data a2a.Task
 	if err := json.Unmarshal([]byte(t.Data), &data); err != nil {
-		return protocol.Task{}, err
+		return a2a.Task{}, err
 	}
 	return data, nil
 }
 
-func ParseTasks(tasks []Task) ([]*protocol.Task, error) {
-	result := make([]*protocol.Task, 0, len(tasks))
+func ParseTasks(tasks []Task) ([]*a2a.Task, error) {
+	result := make([]*a2a.Task, 0, len(tasks))
 	for _, task := range tasks {
 		parsed, err := task.Parse()
 		if err != nil {
@@ -106,12 +107,13 @@ func ParseTasks(tasks []Task) ([]*protocol.Task, error) {
 }
 
 type PushNotification struct {
-	ID        string     `json:"id"`
-	TaskID    string     `json:"task_id"`
-	CreatedAt time.Time  `json:"created_at"`
-	UpdatedAt time.Time  `json:"updated_at"`
-	DeletedAt *time.Time `json:"deleted_at,omitempty"`
-	Data      string     `json:"data"` // JSON-serialized push notification config
+	ID              string     `json:"id"`
+	TaskID          string     `json:"task_id"`
+	CreatedAt       time.Time  `json:"created_at"`
+	UpdatedAt       time.Time  `json:"updated_at"`
+	DeletedAt       *time.Time `json:"deleted_at,omitempty"`
+	Data            string     `json:"data"` // JSON-serialized push notification config
+	ProtocolVersion *string    `json:"protocol_version,omitempty"`
 }
 
 // FeedbackIssueType represents the category of feedback issue

go/api/v1alpha2/agent_types.go

@@ -26,8 +26,6 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/types"
 	"sigs.k8s.io/controller-runtime/pkg/client"
-
-	"trpc.group/trpc-go/trpc-a2a-go/server"
 )
 
 // AgentType represents the agent type
@@ -529,7 +527,33 @@ type A2AConfig struct {
 	Skills []AgentSkill `json:"skills,omitempty"`
 }
 
-type AgentSkill server.AgentSkill
+// AgentSkill describes a specific capability or function of the agent.
+type AgentSkill struct {
+	// ID is the unique identifier for the skill.
+	// +optional
+	ID string `json:"id,omitempty"`
+	// Name is the human-readable name of the skill.
+	// +kubebuilder:validation:MinLength=1
+	// +required
+	Name string `json:"name"`
+	// Description is an optional detailed description of the skill.
+	// +optional
+	Description string `json:"description,omitempty"`
+	// Tags are optional tags for categorization.
+	// +optional
+	// +kubebuilder:validation:MaxItems=20
+	Tags []string `json:"tags,omitempty"`
+	// Examples are optional usage examples.
+	// +optional
+	// +kubebuilder:validation:MaxItems=20
+	Examples []string `json:"examples,omitempty"`
+	// InputModes are the supported input MIME types for this skill, overriding the agent's defaults.
+	// +optional
+	InputModes []string `json:"inputModes,omitempty"`
+	// OutputModes are the supported output MIME types for this skill, overriding the agent's defaults.
+	// +optional
+	OutputModes []string `json:"outputModes,omitempty"`
+}
 
 const (
 	AgentConditionTypeAccepted            = "Accepted"

go/core/internal/a2a/a2a_handler_mux.go

@@ -3,24 +3,27 @@ package a2a
 import (
 	"fmt"
 	"net/http"
+	"slices"
 	"strings"
 	"sync"
 
+	a2atype "github.com/a2aproject/a2a-go/v2/a2a"
+	a2aclient "github.com/a2aproject/a2a-go/v2/a2aclient"
+	"github.com/a2aproject/a2a-go/v2/a2acompat/a2av0"
+	"github.com/a2aproject/a2a-go/v2/a2asrv"
 	"github.com/gorilla/mux"
 	authimpl "github.com/kagent-dev/kagent/go/core/internal/httpserver/auth"
 	common "github.com/kagent-dev/kagent/go/core/internal/utils"
 	"github.com/kagent-dev/kagent/go/core/pkg/auth"
-	"trpc.group/trpc-go/trpc-a2a-go/client"
-	"trpc.group/trpc-go/trpc-a2a-go/server"
 )
 
 // A2AHandlerMux is an interface that defines methods for adding, getting, and removing agentic task handlers.
 type A2AHandlerMux interface {
 	SetAgentHandler(
 		agentRef string,
-		client *client.A2AClient,
-		card server.AgentCard,
-		tracing server.Middleware,
+		client *a2aclient.Client,
+		card a2atype.AgentCard,
+		tracing middleware,
 	) error
 	RemoveAgentHandler(
 		agentRef string,
@@ -38,6 +41,10 @@ type handlerMux struct {
 
 var _ A2AHandlerMux = &handlerMux{}
 
+type middleware interface {
+	Wrap(next http.Handler) http.Handler
+}
+
 func NewA2AHttpMux(agentPathPrefix, sandboxPathPrefix string, authenticator auth.AuthProvider) *handlerMux {
 	return &handlerMux{
 		handlers:          make(map[string]http.Handler),
@@ -49,23 +56,47 @@ func NewA2AHttpMux(agentPathPrefix, sandboxPathPrefix string, authenticator auth
 
 func (a *handlerMux) SetAgentHandler(
 	agentRef string,
-	client *client.A2AClient,
-	card server.AgentCard,
-	tracing server.Middleware,
+	client *a2aclient.Client,
+	card a2atype.AgentCard,
+	tracing middleware,
 ) error {
-	middlewares := []server.Middleware{authimpl.NewA2AAuthenticator(a.authenticator)}
+	requestHandler := NewPassthroughRequestHandler(client, &card)
+	legacyJSONRPCHandler := a2av0.NewJSONRPCHandler(requestHandler)
+	v1JSONRPCHandler := a2asrv.NewJSONRPCHandler(requestHandler)
+	cardHandler := a2asrv.NewAgentCardHandler(a2av0.NewStaticAgentCardProducer(&card))
+	wellKnownPath := "/" + strings.TrimPrefix(a2asrv.WellKnownAgentCardPath, "/")
+
+	var handler http.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasSuffix(r.URL.Path, wellKnownPath) {
+			cardHandler.ServeHTTP(w, r)
+			return
+		}
+		wireVersion, err := common.NegotiateA2AWireVersion(r)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		switch wireVersion {
+		case common.A2AWireVersionLegacy:
+			legacyJSONRPCHandler.ServeHTTP(w, r)
+		case common.A2AWireVersionV1:
+			v1JSONRPCHandler.ServeHTTP(w, r)
+		default:
+			http.Error(w, fmt.Sprintf("unknown negotiated A2A wire version %q", wireVersion), http.StatusBadRequest)
+		}
+	})
+	middlewares := []middleware{authimpl.NewA2AAuthenticator(a.authenticator)}
 	if tracing != nil {
 		middlewares = append(middlewares, tracing)
 	}
-	srv, err := server.NewA2AServer(card, NewPassthroughManager(client), server.WithMiddleWare(middlewares...))
-	if err != nil {
-		return fmt.Errorf("failed to create A2A server: %w", err)
+	for _, middleware := range slices.Backward(middlewares) {
+		handler = middleware.Wrap(handler)
 	}
 
 	a.lock.Lock()
 	defer a.lock.Unlock()
 
-	a.handlers[agentRef] = srv.Handler()
+	a.handlers[agentRef] = handler
 
 	return nil
 }