feat: add implementation of a2a and eino adk extension

a2a/client/client.go

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2025 CloudWeGo Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package client
+
+import (
+	"context"
+	"errors"
+
+	"github.com/cloudwego/eino-ext/a2a/models"
+	"github.com/cloudwego/eino-ext/a2a/transport"
+)
+
+// A2AClient represents an A2A protocol client
+type A2AClient struct {
+	cli transport.ClientTransport
+}
+
+type Config struct {
+	Transport transport.ClientTransport
+}
+
+// NewA2AClient creates a new A2A client
+func NewA2AClient(ctx context.Context, config *Config) (*A2AClient, error) {
+	if config == nil {
+		return nil, errors.New("config is required")
+	}
+
+	return &A2AClient{cli: config.Transport}, nil
+}
+
+func (c *A2AClient) AgentCard(ctx context.Context) (*models.AgentCard, error) {
+	return c.cli.AgentCard(ctx)
+}
+
+func (c *A2AClient) SendMessage(ctx context.Context, params *models.MessageSendParams) (*models.SendMessageResponseUnion, error) {
+	if params != nil {
+		(&params.Message).EnsureRequiredFields()
+	}
+	return c.cli.SendMessage(ctx, params)
+}
+
+func (c *A2AClient) SendMessageStreaming(ctx context.Context, params *models.MessageSendParams) (*ServerStreamingWrapper, error) {
+	if params != nil {
+		(&params.Message).EnsureRequiredFields()
+	}
+	stream, err := c.cli.SendMessageStreaming(ctx, params)
+	if err != nil {
+		return nil, err
+	}
+	return &ServerStreamingWrapper{stream}, nil
+}
+
+func (c *A2AClient) GetTask(ctx context.Context, params *models.TaskQueryParams) (*models.Task, error) {
+	return c.cli.GetTask(ctx, params)
+}
+
+func (c *A2AClient) CancelTask(ctx context.Context, params *models.TaskIDParams) (*models.Task, error) {
+	return c.cli.CancelTask(ctx, params)
+}
+
+func (c *A2AClient) ResubscribeTask(ctx context.Context, params *models.TaskIDParams) (*ServerStreamingWrapper, error) {
+	stream, err := c.cli.ResubscribeTask(ctx, params)
+	if err != nil {
+		return nil, err
+	}
+	return &ServerStreamingWrapper{stream}, nil
+}
+
+func (c *A2AClient) SetPushNotificationConfig(ctx context.Context, params *models.TaskPushNotificationConfig) (*models.TaskPushNotificationConfig, error) {
+	return c.cli.SetPushNotificationConfig(ctx, params)
+}
+
+func (c *A2AClient) GetPushNotificationConfig(ctx context.Context, params *models.GetTaskPushNotificationConfigParams) (*models.TaskPushNotificationConfig, error) {
+	return c.cli.GetPushNotificationConfig(ctx, params)
+}
+
+// todo: list/delete notification config & agent/authenticatedExtendedCard
+
+type ServerStreamingWrapper struct {
+	s models.ResponseReader
+}
+
+func (s *ServerStreamingWrapper) Recv() (resp *models.SendMessageStreamingResponseUnion, err error) {
+	defer func() {
+		if err != nil {
+			s.s.Close()
+		}
+	}()
+	return s.s.Read()
+}
+
+func (s *ServerStreamingWrapper) Close() error {
+	return s.s.Close()
+}

a2a/client/client_test.go

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2025 CloudWeGo Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package client