chore(a2a): migrate from adka2a to adka2a/v2

.golangci.yml

@@ -182,11 +182,6 @@ linters:
         linters:
           - staticcheck
         text: "SA1019:.*FunctionCall.*deprecated"
-      # adka2a/v2 migration requires a full a2a-go v2 upgrade (separate PR)
-      - path: pkg/a2a/
-        linters:
-          - staticcheck
-        text: "SA1019:.*adka2a.*deprecated"
       # MCP sampling (SEP-2577) is deprecated upstream but functional during
       # the deprecation window; migrating off it is a separate effort
       - path: ^(e2e/sampling_test|pkg/runtime/sampling(_test)?|pkg/tools/sampling|pkg/tools/codemode/codemode_test|pkg/tools/mcp/(mcp|session_client)(_test)?)\.go$

e2e/a2a_test.go

@@ -11,8 +11,8 @@ import (
 	"testing"
 	"time"
 
-	"github.com/a2aproject/a2a-go/a2a"
-	"github.com/a2aproject/a2a-go/a2asrv"
+	"github.com/a2aproject/a2a-go/v2/a2a"
+	"github.com/a2aproject/a2a-go/v2/a2asrv"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -27,27 +27,24 @@ type a2aResponse struct {
 	ID      string `json:"id"`
 	Error   any    `json:"error,omitempty"`
 
-	// Result holds the task with its artifacts.
-	Result *struct {
-		Artifacts []struct {
-			Parts []struct {
-				Kind string `json:"kind"`
-				Text string `json:"text"`
-			} `json:"parts"`
-		} `json:"artifacts"`
-	} `json:"result,omitempty"`
+	// Result holds the produced event, e.g. the task with its artifacts.
+	Result *a2a.StreamResponse `json:"result,omitempty"`
 }
 
 // textParts returns all text parts across every artifact in the response.
 func (r *a2aResponse) textParts() []string {
 	if r.Result == nil {
 		return nil
 	}
+	task, ok := r.Result.Event.(*a2a.Task)
+	if !ok {
+		return nil
+	}
 	var texts []string
-	for _, a := range r.Result.Artifacts {
+	for _, a := range task.Artifacts {
 		for _, p := range a.Parts {
-			if p.Kind == "text" {
-				texts = append(texts, p.Text)
+			if _, ok := p.Content.(a2a.Text); ok {
+				texts = append(texts, p.Text())
 			}
 		}
 	}
@@ -62,8 +59,9 @@ func TestA2AServer_AgentCard(t *testing.T) {
 
 	assert.Equal(t, "basic", agentCard.Name)
 	assert.NotEmpty(t, agentCard.Description)
-	assert.Equal(t, a2a.TransportProtocolJSONRPC, agentCard.PreferredTransport)
-	assert.Contains(t, agentCard.URL, "/invoke")
+	require.Len(t, agentCard.SupportedInterfaces, 1)
+	assert.Equal(t, a2a.TransportProtocolJSONRPC, agentCard.SupportedInterfaces[0].ProtocolBinding)
+	assert.Contains(t, agentCard.SupportedInterfaces[0].URL, "/invoke")
 	assert.True(t, agentCard.Capabilities.Streaming)
 	assert.NotEmpty(t, agentCard.Version)
 }
@@ -74,7 +72,7 @@ func TestA2AServer_Invoke(t *testing.T) {
 	_, runConfig := startRecordingAIProxy(t)
 	agentCard := startA2AServer(t, "testdata/basic.yaml", runConfig)
 
-	resp := sendA2AMessage(t, agentCard.URL, "test-request-1", "msg-1", "What is 2+2? Answer with just the number.")
+	resp := sendA2AMessage(t, invokeURL(t, agentCard), "test-request-1", "msg-1", "What is 2+2? Answer with just the number.")
 
 	assert.Equal(t, "2.0", resp.Jsonrpc)
 	assert.Equal(t, "test-request-1", resp.ID)
@@ -104,7 +102,7 @@ func TestA2AServer_MultipleRequests(t *testing.T) {
 			requestID := fmt.Sprintf("test-request-%d", i)
 			msgID := fmt.Sprintf("msg-%d", i)
 
-			resp := sendA2AMessage(t, agentCard.URL, requestID, msgID, message)
+			resp := sendA2AMessage(t, invokeURL(t, agentCard), requestID, msgID, message)
 
 			assert.Equal(t, requestID, resp.ID)
 			assert.Nil(t, resp.Error)
@@ -119,7 +117,7 @@ func TestA2AServer_MultiAgent(t *testing.T) {
 	_, runConfig := startRecordingAIProxy(t)
 	agentCard := startA2AServer(t, "testdata/multi.yaml", runConfig)
 
-	resp := sendA2AMessage(t, agentCard.URL, "test-multi-1", "msg-multi-1", "Say hello.")
+	resp := sendA2AMessage(t, invokeURL(t, agentCard), "test-multi-1", "msg-multi-1", "Say hello.")
 
 	assert.Equal(t, "test-multi-1", resp.ID)
 	assert.Nil(t, resp.Error)
@@ -130,21 +128,25 @@ func TestA2AServer_MultiAgent(t *testing.T) {
 	assert.Contains(t, texts[len(texts)-1], "Hello")
 }
 
-// sendA2AMessage sends a message/send JSON-RPC request and returns the parsed response.
+// invokeURL returns the JSON-RPC endpoint advertised by the agent card.
+func invokeURL(t *testing.T, card a2a.AgentCard) string {
+	t.Helper()
+
+	require.NotEmpty(t, card.SupportedInterfaces)
+	return card.SupportedInterfaces[0].URL
+}
+
+// sendA2AMessage sends a SendMessage JSON-RPC request and returns the parsed response.
 func sendA2AMessage(t *testing.T, url, requestID, messageID, text string) a2aResponse {
 	t.Helper()
 
+	message := a2a.NewMessage(a2a.MessageRoleUser, a2a.NewTextPart(text))
+	message.ID = messageID
 	body, err := json.Marshal(map[string]any{
 		"jsonrpc": "2.0",
 		"id":      requestID,
-		"method":  "message/send",
-		"params": map[string]any{
-			"message": map[string]any{
-				"messageId": messageID,
-				"role":      "user",
-				"parts":     []map[string]any{{"kind": "text", "text": text}},
-			},
-		},
+		"method":  "SendMessage",
+		"params":  &a2a.SendMessageRequest{Message: message},
 	})
 	require.NoError(t, err)
 

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/Masterminds/semver/v3 v3.5.0
 	github.com/Microsoft/go-winio v0.6.2
 	github.com/a2aproject/a2a-go v0.3.15
+	github.com/a2aproject/a2a-go/v2 v2.4.0
 	github.com/alecthomas/chroma/v2 v2.27.0
 	github.com/alpkeskin/gotoon v0.1.1
 	github.com/anthropics/anthropic-sdk-go v1.66.0
@@ -104,7 +105,6 @@ require (
 	github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c // indirect
 	github.com/JohannesKaufmann/dom v0.3.1 // indirect
 	github.com/ProtonMail/go-crypto v1.1.6 // indirect
-	github.com/a2aproject/a2a-go/v2 v2.4.0 // indirect
 	github.com/agext/levenshtein v1.2.1 // indirect
 	github.com/apparentlymart/go-textseg/v15 v15.0.0 // indirect
 	github.com/apparentlymart/go-textseg/v17 v17.0.1 // indirect

pkg/a2a/executor_wrapper.go

@@ -2,11 +2,11 @@ package a2a
 
 import (
 	"context"
+	"iter"
 
-	"github.com/a2aproject/a2a-go/a2a"
-	"github.com/a2aproject/a2a-go/a2asrv"
-	"github.com/a2aproject/a2a-go/a2asrv/eventqueue"
-	"google.golang.org/adk/v2/server/adka2a"
+	"github.com/a2aproject/a2a-go/v2/a2a"
+	"github.com/a2aproject/a2a-go/v2/a2asrv"
+	adka2a "google.golang.org/adk/v2/server/adka2a/v2"
 )
 
 // executorWrapper wraps an ADK executor and fixes artifact update events
@@ -15,48 +15,45 @@ type executorWrapper struct {
 	executor *adka2a.Executor
 }
 
+var (
+	_ a2asrv.AgentExecutor         = (*executorWrapper)(nil)
+	_ a2asrv.AgentExecutionCleaner = (*executorWrapper)(nil)
+)
+
 func newExecutorWrapper(config adka2a.ExecutorConfig) *executorWrapper {
 	return &executorWrapper{
 		executor: adka2a.NewExecutor(config),
 	}
 }
 
-func (w *executorWrapper) Execute(ctx context.Context, reqCtx *a2asrv.RequestContext, queue eventqueue.Queue) error {
-	// Create a wrapping queue that fixes events before sending them
-	fixedQueue := &fixingQueue{
-		queue: queue,
-	}
-	return w.executor.Execute(ctx, reqCtx, fixedQueue)
+func (w *executorWrapper) Execute(ctx context.Context, execCtx *a2asrv.ExecutorContext) iter.Seq2[a2a.Event, error] {
+	return fixArtifactEvents(w.executor.Execute(ctx, execCtx))
 }
 
-func (w *executorWrapper) Cancel(ctx context.Context, reqCtx *a2asrv.RequestContext, queue eventqueue.Queue) error {
-	return w.executor.Cancel(ctx, reqCtx, queue)
+func (w *executorWrapper) Cancel(ctx context.Context, execCtx *a2asrv.ExecutorContext) iter.Seq2[a2a.Event, error] {
+	return w.executor.Cancel(ctx, execCtx)
 }
 
-// fixingQueue wraps an eventqueue.Queue and fixes artifact update events
-type fixingQueue struct {
-	queue eventqueue.Queue
+// Cleanup delegates to the ADK executor, which implements
+// a2asrv.AgentExecutionCleaner; dropping it would change cleanup semantics.
+func (w *executorWrapper) Cleanup(ctx context.Context, execCtx *a2asrv.ExecutorContext, result a2a.SendMessageResult, err error) {
+	w.executor.Cleanup(ctx, execCtx, result, err)
 }
 
-func (fq *fixingQueue) Write(ctx context.Context, event a2a.Event) error {
-	// Fix artifact update events with nil Parts
-	if artifactEvent, ok := event.(*a2a.TaskArtifactUpdateEvent); ok {
-		if artifactEvent.Artifact != nil && artifactEvent.Artifact.Parts == nil {
-			// Replace nil with an empty slice
-			artifactEvent.Artifact.Parts = []a2a.Part{}
+// fixArtifactEvents wraps an event sequence and fixes artifact update events
+// with nil Parts before yielding them. Everything else passes through unchanged.
+func fixArtifactEvents(events iter.Seq2[a2a.Event, error]) iter.Seq2[a2a.Event, error] {
+	return func(yield func(a2a.Event, error) bool) {
+		for event, err := range events {
+			if artifactEvent, ok := event.(*a2a.TaskArtifactUpdateEvent); ok {
+				if artifactEvent.Artifact != nil && artifactEvent.Artifact.Parts == nil {
+					// Replace nil with an empty slice
+					artifactEvent.Artifact.Parts = a2a.ContentParts{}
+				}
+			}
+			if !yield(event, err) {
+				return
+			}
 		}
 	}
-	return fq.queue.Write(ctx, event)
-}
-
-func (fq *fixingQueue) Read(ctx context.Context) (a2a.Event, a2a.TaskVersion, error) {
-	return fq.queue.Read(ctx)
-}
-
-func (fq *fixingQueue) WriteVersioned(ctx context.Context, event a2a.Event, version a2a.TaskVersion) error {
-	return fq.queue.WriteVersioned(ctx, event, version)
-}
-
-func (fq *fixingQueue) Close() error {
-	return fq.queue.Close()
 }