diff --git a/agent/output/jsapi/README.md b/agent/output/jsapi/README.md
new file mode 100644
index 00000000..5aabb03f
--- /dev/null
+++ b/agent/output/jsapi/README.md
@@ -0,0 +1,482 @@
+# Output JSAPI
+
+The Output JSAPI provides a JavaScript interface for sending output messages to clients from scripts (e.g., hooks, processes). It wraps the Go `output` package functionality and provides a convenient API for sending messages and message groups.
+
+## Overview
+
+The Output object allows you to:
+
+- Send individual messages to clients in various formats (text, error, loading, etc.)
+- Send groups of related messages
+- Support streaming with delta updates
+- Handle different message types with custom properties
+
+## Constructor
+
+### `new Output(ctx)`
+
+Creates a new Output instance.
+
+**Parameters:**
+
+- `ctx` (Context): The agent context object
+
+**Returns:**
+
+- Output instance
+
+**Example:**
+
+```javascript
+function Create(ctx, messages) {
+  const output = new Output(ctx);
+  // Use output methods...
+}
+```
+
+## Methods
+
+### `Send(message)`
+
+Sends a single message to the client.
+
+**Parameters:**
+
+- `message` (string | object): The message to send
+  - If string: Automatically converted to a text message
+  - If object: Must have a `type` field and optional `props` and other fields
+
+**Returns:**
+
+- Output instance (for chaining)
+
+**Message Object Structure:**
+
+```javascript
+{
+  type: string,              // Required: Message type (e.g., "text", "error", "loading")
+  props: object,             // Optional: Message properties (type-specific)
+  id: string,                // Optional: Message ID (for streaming)
+  delta: boolean,            // Optional: Whether this is a delta update
+  done: boolean,             // Optional: Whether the message is complete
+  delta_path: string,        // Optional: Path for delta updates (e.g., "content")
+  delta_action: string,      // Optional: Delta action ("append", "replace", "merge", "set")
+  type_change: boolean,      // Optional: Whether this is a type correction
+  group_id: string,          // Optional: Parent message group ID
+  group_start: boolean,      // Optional: Marks the start of a message group
+  group_end: boolean,        // Optional: Marks the end of a message group
+  metadata: {                // Optional: Message metadata
+    timestamp: number,
+    sequence: number,
+    trace_id: string
+  }
+}
+```
+
+**Examples:**
+
+Send a simple text message (shorthand):
+
+```javascript
+output.Send("Hello, world!");
+```
+
+Send a text message (full):
+
+```javascript
+output.Send({
+  type: "text",
+  props: {
+    content: "Hello, world!",
+  },
+});
+```
+
+Send an error message:
+
+```javascript
+output.Send({
+  type: "error",
+  props: {
+    message: "Something went wrong",
+    code: "ERR_001",
+    details: "Additional error details",
+  },
+});
+```
+
+Send a loading indicator:
+
+```javascript
+output.Send({
+  type: "loading",
+  props: {
+    message: "Searching knowledge base...",
+  },
+});
+```
+
+Send streaming text with delta updates:
+
+```javascript
+// First chunk
+output.Send({
+  type: "text",
+  id: "msg-1",
+  props: { content: "Hello" },
+  delta: true,
+  done: false,
+});
+
+// Subsequent chunks
+output.Send({
+  type: "text",
+  id: "msg-1",
+  props: { content: " world" },
+  delta: true,
+  delta_path: "content",
+  delta_action: "append",
+  done: false,
+});
+
+// Final chunk
+output.Send({
+  type: "text",
+  id: "msg-1",
+  props: { content: "!" },
+  delta: true,
+  delta_path: "content",
+  delta_action: "append",
+  done: true,
+});
+```
+
+Chain multiple sends:
+
+```javascript
+output
+  .Send("First message")
+  .Send("Second message")
+  .Send({ type: "loading", props: { message: "Processing..." } });
+```
+
+### `SendGroup(group)`
+
+Sends a group of related messages.
+
+**Parameters:**
+
+- `group` (object): The message group
+  - `id` (string): Required - Group ID
+  - `messages` (array): Required - Array of message objects
+  - `metadata` (object): Optional - Group metadata
+
+**Returns:**
+
+- Output instance (for chaining)
+
+**Group Object Structure:**
+
+```javascript
+{
+  id: string,                // Required: Message group ID
+  messages: [                // Required: Array of messages
+    {
+      type: string,
+      props: object,
+      // ... other message fields
+    }
+  ],
+  metadata: {                // Optional: Group metadata
+    timestamp: number,
+    sequence: number,
+    trace_id: string
+  }
+}
+```
+
+**Examples:**
+
+Send a simple message group:
+
+```javascript
+output.SendGroup({
+  id: "search-results",
+  messages: [
+    { type: "text", props: { content: "Found 3 results:" } },
+    { type: "text", props: { content: "Result 1" } },
+    { type: "text", props: { content: "Result 2" } },
+    { type: "text", props: { content: "Result 3" } },
+  ],
+});
+```
+
+Send a group with metadata:
+
+```javascript
+output.SendGroup({
+  id: "analysis-group",
+  messages: [
+    { type: "loading", props: { message: "Analyzing data..." } },
+    { type: "text", props: { content: "Analysis complete" } },
+  ],
+  metadata: {
+    timestamp: Date.now(),
+    sequence: 1,
+    trace_id: "trace-123",
+  },
+});
+```
+
+## Built-in Message Types
+
+The Output JSAPI supports all built-in message types defined in the output package:
+
+### User Interaction Types
+
+- **`user_input`**: User input message (frontend display only)
+  ```javascript
+  { type: "user_input", props: { content: "User's message", role: "user" } }
+  ```
+
+### Content Types
+
+- **`text`**: Plain text or Markdown content
+
+  ```javascript
+  { type: "text", props: { content: "Hello **world**" } }
+  ```
+
+- **`thinking`**: Reasoning/thinking process (e.g., o1 models)
+
+  ```javascript
+  { type: "thinking", props: { content: "Let me think about this..." } }
+  ```
+
+- **`loading`**: Loading/processing indicator
+
+  ```javascript
+  { type: "loading", props: { message: "Processing..." } }
+  ```
+
+- **`tool_call`**: LLM tool/function call
+
+  ```javascript
+  {
+    type: "tool_call",
+    props: {
+      id: "call_123",
+      name: "search",
+      arguments: "{\"query\":\"test\"}"
+    }
+  }
+  ```
+
+- **`error`**: Error message
+  ```javascript
+  {
+    type: "error",
+    props: {
+      message: "Error occurred",
+      code: "ERR_001",
+      details: "More info"
+    }
+  }
+  ```
+
+### Media Types
+
+- **`image`**: Image content
+
+  ```javascript
+  {
+    type: "image",
+    props: {
+      url: "https://example.com/image.jpg",
+      alt: "Description",
+      width: 800,
+      height: 600
+    }
+  }
+  ```
+
+- **`audio`**: Audio content
+
+  ```javascript
+  {
+    type: "audio",
+    props: {
+      url: "https://example.com/audio.mp3",
+      format: "mp3",
+      duration: 120.5
+    }
+  }
+  ```
+
+- **`video`**: Video content
+  ```javascript
+  {
+    type: "video",
+    props: {
+      url: "https://example.com/video.mp4",
+      format: "mp4",
+      duration: 300
+    }
+  }
+  ```
+
+### System Types
+
+- **`action`**: System action (silent in OpenAI clients)
+
+  ```javascript
+  {
+    type: "action",
+    props: {
+      name: "open_panel",
+      payload: { panel_id: "settings" }
+    }
+  }
+  ```
+
+- **`event`**: Lifecycle event (CUI only, silent in OpenAI clients)
+  ```javascript
+  {
+    type: "event",
+    props: {
+      event: "stream_start",
+      message: "Starting stream..."
+    }
+  }
+  ```
+
+## Usage in Hooks
+
+### Create Hook Example
+
+```javascript
+/**
+ * Create hook - Called before sending messages to the LLM
+ * @param {Context} ctx - Agent context
+ * @param {Array} messages - User messages
+ * @returns {Object} Hook response
+ */
+function Create(ctx, messages) {
+  const output = new Output(ctx);
+
+  // Send a loading indicator
+  output.Send({
+    type: "loading",
+    props: { message: "Processing your request..." },
+  });
+
+  // Send custom messages to the user
+  output.Send({
+    type: "text",
+    props: { content: "I'm thinking about your question..." },
+  });
+
+  // Return hook response
+  return {
+    messages: messages,
+    temperature: 0.7,
+  };
+}
+```
+
+### Done Hook Example
+
+```javascript
+/**
+ * Done hook - Called after assistant completes response
+ * @param {Context} ctx - Agent context
+ * @param {Array} messages - Conversation messages
+ * @param {Object} response - Assistant response
+ */
+function Done(ctx, messages, response) {
+  const output = new Output(ctx);
+
+  // Send a completion message
+  output.Send({
+    type: "text",
+    props: { content: "Response complete!" },
+  });
+
+  // Send an action
+  output.Send({
+    type: "action",
+    props: {
+      name: "save_conversation",
+      payload: { chat_id: ctx.chat_id },
+    },
+  });
+}
+```
+
+### Progress Updates Example
+
+```javascript
+function ProcessData(ctx, data) {
+  const output = new Output(ctx);
+
+  // Show progress
+  const steps = ["Loading", "Processing", "Analyzing", "Complete"];
+
+  for (let i = 0; i < steps.length; i++) {
+    output.Send({
+      type: "loading",
+      props: {
+        message: `${steps[i]}... (${i + 1}/${steps.length})`,
+      },
+    });
+
+    // Do some work...
+    processStep(i);
+  }
+
+  // Send final result
+  output.Send({
+    type: "text",
+    props: { content: "All done!" },
+  });
+}
+```
+
+## Error Handling
+
+The Output JSAPI throws exceptions for invalid parameters:
+
+```javascript
+try {
+  const output = new Output(ctx);
+
+  // This will throw: message.type is required
+  output.Send({ props: { content: "test" } });
+} catch (e) {
+  console.error("Output error:", e.toString());
+}
+```
+
+Common errors:
+
+- `"Output constructor requires a context argument"` - Missing ctx parameter
+- `"Send requires a message argument"` - Missing message parameter
+- `"message.type is required and must be a string"` - Missing or invalid type field
+- `"SendGroup requires a group argument"` - Missing group parameter
+- `"group.id is required and must be a string"` - Missing group ID
+- `"group.messages is required and must be an array"` - Missing or invalid messages array
+
+## Notes
+
+1. **Context Requirement**: The Output object must be created with a valid agent context
+2. **Writer Required**: The context must have a Writer set (automatically handled in API requests)
+3. **Message Format**: Messages are automatically adapted based on the context's Accept type (standard, cui-web, cui-native, cui-desktop)
+4. **Streaming**: For streaming responses, use delta updates with proper message IDs
+5. **Method Chaining**: All methods return the Output instance for convenient chaining
+
+## See Also
+
+- [Output Package Documentation](../README.md)
+- [Message Types](../BUILTIN_TYPES.md)
+- [Agent Context](../../context/README.md)
+- [Hook System](../../assistant/hook/README.md)
diff --git a/agent/output/jsapi/output.go b/agent/output/jsapi/output.go
new file mode 100644
index 00000000..07acbbec
--- /dev/null
+++ b/agent/output/jsapi/output.go
@@ -0,0 +1,412 @@
+package jsapi
+
+import (
+	"fmt"
+
+	v8 "github.com/yaoapp/gou/runtime/v8"
+	"github.com/yaoapp/gou/runtime/v8/bridge"
+	agentContext "github.com/yaoapp/yao/agent/context"
+	"github.com/yaoapp/yao/agent/output"
+	"github.com/yaoapp/yao/agent/output/message"
+	"rogchap.com/v8go"
+)
+
+func init() {
+	// Auto-register Output JavaScript API when package is imported
+	v8.RegisterFunction("Output", ExportFunction)
+}
+
+// Usage from JavaScript:
+//
+//	const output = new Output(ctx)
+//	output.Send({ type: "text", props: { content: "Hello" } })
+//	output.Send("Hello") // shorthand for text message
+//	output.SendGroup({ id: "group1", messages: [...] })
+//
+// Objects:
+//   - Output: Output manager (constructor)
+
+// ExportFunction exports the Output constructor function template
+// This is used by v8.RegisterFunction
+func ExportFunction(iso *v8go.Isolate) *v8go.FunctionTemplate {
+	return v8go.NewFunctionTemplate(iso, outputConstructor)
+}
+
+// outputConstructor is the JavaScript constructor for Output
+// Usage: new Output(ctx)
+func outputConstructor(info *v8go.FunctionCallbackInfo) *v8go.Value {
+	v8ctx := info.Context()
+	args := info.Args()
+
+	// Require ctx argument
+	if len(args) < 1 {
+		return bridge.JsException(v8ctx, "Output constructor requires a context argument")
+	}
+
+	// Get the context object from JavaScript
+	ctxObj, err := args[0].AsObject()
+	if err != nil {
+		return bridge.JsException(v8ctx, fmt.Sprintf("context must be an object: %s", err))
+	}
+
+	// Get the goValueID from internal field (index 0)
+	if ctxObj.InternalFieldCount() < 1 {
+		return bridge.JsException(v8ctx, "context object is missing internal fields")
+	}
+
+	goValueIDValue := ctxObj.GetInternalField(0)
+	if goValueIDValue == nil || !goValueIDValue.IsString() {
+		return bridge.JsException(v8ctx, "context object is missing goValueID")
+	}
+
+	goValueID := goValueIDValue.String()
+
+	// Retrieve the Go context object from bridge registry
+	goObj := bridge.GetGoObject(goValueID)
+	if goObj == nil {
+		return bridge.JsException(v8ctx, "context object not found in registry")
+	}
+
+	// Type assert to *agentContext.Context
+	ctx, ok := goObj.(*agentContext.Context)
+	if !ok {
+		return bridge.JsException(v8ctx, fmt.Sprintf("object is not a Context, got %T", goObj))
+	}
+
+	// Create output object
+	outputObj, err := NewOutputObject(v8ctx, ctx)
+	if err != nil {
+		return bridge.JsException(v8ctx, err.Error())
+	}
+
+	return outputObj
+}
+
+// NewOutputObject creates a JavaScript Output object
+func NewOutputObject(v8ctx *v8go.Context, ctx *agentContext.Context) (*v8go.Value, error) {
+	jsObject := v8go.NewObjectTemplate(v8ctx.Isolate())
+
+	// Set internal field count to 1 to store the __go_id
+	// Internal fields are not accessible from JavaScript, providing better security
+	jsObject.SetInternalFieldCount(1)
+
+	// Register context in global bridge registry for efficient Go object retrieval
+	// The goValueID will be stored in internal field (index 0) after instance creation
+	goValueID := bridge.RegisterGoObject(ctx)
+
+	// Set methods
+	jsObject.Set("Send", outputSendMethod(v8ctx.Isolate(), ctx))
+	jsObject.Set("SendGroup", outputSendGroupMethod(v8ctx.Isolate(), ctx))
+
+	// Set release function that will be called when JavaScript object is released
+	jsObject.Set("__release", outputGoRelease(v8ctx.Isolate()))
+
+	// Create instance
+	instance, err := jsObject.NewInstance(v8ctx)
+	if err != nil {
+		// Clean up: release from global registry if instance creation failed
+		bridge.ReleaseGoObject(goValueID)
+		return nil, err
+	}
+
+	// Store the goValueID in internal field (index 0)
+	// This is not accessible from JavaScript, providing better security
+	obj, err := instance.Value.AsObject()
+	if err != nil {
+		bridge.ReleaseGoObject(goValueID)
+		return nil, err
+	}
+
+	err = obj.SetInternalField(0, goValueID)
+	if err != nil {
+		bridge.ReleaseGoObject(goValueID)
+		return nil, err
+	}
+
+	return instance.Value, nil
+}
+
+// outputGoRelease releases the Go object from the global bridge registry
+// It retrieves the goValueID from internal field (index 0) and releases the Go object
+func outputGoRelease(iso *v8go.Isolate) *v8go.FunctionTemplate {
+	return v8go.NewFunctionTemplate(iso, func(info *v8go.FunctionCallbackInfo) *v8go.Value {
+		// Get the output object (this)
+		thisObj, err := info.This().AsObject()
+		if err == nil && thisObj.InternalFieldCount() > 0 {
+			// Get goValueID from internal field (index 0)
+			goValueIDValue := thisObj.GetInternalField(0)
+			if goValueIDValue != nil && goValueIDValue.IsString() {
+				goValueID := goValueIDValue.String()
+				// Release from global bridge registry
+				bridge.ReleaseGoObject(goValueID)
+			}
+		}
+
+		return v8go.Undefined(info.Context().Isolate())
+	})
+}
+
+// outputSendMethod implements the Send method
+// Usage: output.Send(message)
+// message can be an object with { type: string, props: object, ... } or a simple string (will be converted to text message)
+func outputSendMethod(iso *v8go.Isolate, ctx *agentContext.Context) *v8go.FunctionTemplate {
+	return v8go.NewFunctionTemplate(iso, func(info *v8go.FunctionCallbackInfo) *v8go.Value {
+		v8ctx := info.Context()
+		args := info.Args()
+
+		if len(args) < 1 {
+			return bridge.JsException(v8ctx, "Send requires a message argument")
+		}
+
+		// Parse message argument
+		msg, err := parseMessage(v8ctx, args[0])
+		if err != nil {
+			return bridge.JsException(v8ctx, fmt.Sprintf("invalid message: %s", err))
+		}
+
+		// Call output.Send
+		if err := output.Send(ctx, msg); err != nil {
+			return bridge.JsException(v8ctx, fmt.Sprintf("Send failed: %s", err))
+		}
+
+		return info.This().Value
+	})
+}
+
+// outputSendGroupMethod implements the SendGroup method
+// Usage: output.SendGroup(group)
+// group must be an object with { id: string, messages: [], ... }
+func outputSendGroupMethod(iso *v8go.Isolate, ctx *agentContext.Context) *v8go.FunctionTemplate {
+	return v8go.NewFunctionTemplate(iso, func(info *v8go.FunctionCallbackInfo) *v8go.Value {
+		v8ctx := info.Context()
+		args := info.Args()
+
+		if len(args) < 1 {
+			return bridge.JsException(v8ctx, "SendGroup requires a group argument")
+		}
+
+		// Parse group argument
+		group, err := parseGroup(v8ctx, args[0])
+		if err != nil {
+			return bridge.JsException(v8ctx, fmt.Sprintf("invalid group: %s", err))
+		}
+
+		// Call output.SendGroup
+		if err := output.SendGroup(ctx, group); err != nil {
+			return bridge.JsException(v8ctx, fmt.Sprintf("SendGroup failed: %s", err))
+		}
+
+		return info.This().Value
+	})
+}
+
+// parseMessage parses a JavaScript value into a message.Message
+func parseMessage(v8ctx *v8go.Context, jsValue *v8go.Value) (*message.Message, error) {
+	// Handle string shorthand: convert to text message
+	if jsValue.IsString() {
+		return &message.Message{
+			Type: message.TypeText,
+			Props: map[string]interface{}{
+				"content": jsValue.String(),
+			},
+		}, nil
+	}
+
+	// Handle object
+	if !jsValue.IsObject() {
+		return nil, fmt.Errorf("message must be a string or object")
+	}
+
+	// Convert to Go map
+	goValue, err := bridge.GoValue(jsValue, v8ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to convert message: %w", err)
+	}
+
+	msgMap, ok := goValue.(map[string]interface{})
+	if !ok {
+		return nil, fmt.Errorf("message must be an object")
+	}
+
+	// Build message
+	msg := &message.Message{}
+
+	// Type field (required)
+	if msgType, ok := msgMap["type"].(string); ok {
+		msg.Type = msgType
+	} else {
+		return nil, fmt.Errorf("message.type is required and must be a string")
+	}
+
+	// Props field (optional)
+	if props, ok := msgMap["props"].(map[string]interface{}); ok {
+		msg.Props = props
+	}
+
+	// Optional fields
+	if id, ok := msgMap["id"].(string); ok {
+		msg.ID = id
+	}
+	if delta, ok := msgMap["delta"].(bool); ok {
+		msg.Delta = delta
+	}
+	if done, ok := msgMap["done"].(bool); ok {
+		msg.Done = done
+	}
+	if deltaPath, ok := msgMap["delta_path"].(string); ok {
+		msg.DeltaPath = deltaPath
+	}
+	if deltaAction, ok := msgMap["delta_action"].(string); ok {
+		msg.DeltaAction = deltaAction
+	}
+	if typeChange, ok := msgMap["type_change"].(bool); ok {
+		msg.TypeChange = typeChange
+	}
+	if groupID, ok := msgMap["group_id"].(string); ok {
+		msg.GroupID = groupID
+	}
+	if groupStart, ok := msgMap["group_start"].(bool); ok {
+		msg.GroupStart = groupStart
+	}
+	if groupEnd, ok := msgMap["group_end"].(bool); ok {
+		msg.GroupEnd = groupEnd
+	}
+
+	// Metadata (optional)
+	if metadataMap, ok := msgMap["metadata"].(map[string]interface{}); ok {
+		metadata := &message.Metadata{}
+		if timestamp, ok := metadataMap["timestamp"].(float64); ok {
+			metadata.Timestamp = int64(timestamp)
+		}
+		if sequence, ok := metadataMap["sequence"].(float64); ok {
+			metadata.Sequence = int(sequence)
+		}
+		if traceID, ok := metadataMap["trace_id"].(string); ok {
+			metadata.TraceID = traceID
+		}
+		msg.Metadata = metadata
+	}
+
+	return msg, nil
+}
+
+// parseGroup parses a JavaScript value into a message.Group
+func parseGroup(v8ctx *v8go.Context, jsValue *v8go.Value) (*message.Group, error) {
+	// Must be an object
+	if !jsValue.IsObject() {
+		return nil, fmt.Errorf("group must be an object")
+	}
+
+	// Convert to Go map
+	goValue, err := bridge.GoValue(jsValue, v8ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to convert group: %w", err)
+	}
+
+	groupMap, ok := goValue.(map[string]interface{})
+	if !ok {
+		return nil, fmt.Errorf("group must be an object")
+	}
+
+	// Build group
+	group := &message.Group{}
+
+	// ID field (required)
+	if id, ok := groupMap["id"].(string); ok {
+		group.ID = id
+	} else {
+		return nil, fmt.Errorf("group.id is required and must be a string")
+	}
+
+	// Messages field (required)
+	if messagesArray, ok := groupMap["messages"].([]interface{}); ok {
+		group.Messages = make([]*message.Message, 0, len(messagesArray))
+		for i, msgInterface := range messagesArray {
+			// Convert to map
+			msgMap, ok := msgInterface.(map[string]interface{})
+			if !ok {
+				return nil, fmt.Errorf("group.messages[%d] must be an object", i)
+			}
+
+			// Convert map to Message
+			msg := &message.Message{}
+
+			// Type field (required)
+			if msgType, ok := msgMap["type"].(string); ok {
+				msg.Type = msgType
+			} else {
+				return nil, fmt.Errorf("group.messages[%d].type is required", i)
+			}
+
+			// Props field (optional)
+			if props, ok := msgMap["props"].(map[string]interface{}); ok {
+				msg.Props = props
+			}
+
+			// Optional fields
+			if id, ok := msgMap["id"].(string); ok {
+				msg.ID = id
+			}
+			if delta, ok := msgMap["delta"].(bool); ok {
+				msg.Delta = delta
+			}
+			if done, ok := msgMap["done"].(bool); ok {
+				msg.Done = done
+			}
+			if deltaPath, ok := msgMap["delta_path"].(string); ok {
+				msg.DeltaPath = deltaPath
+			}
+			if deltaAction, ok := msgMap["delta_action"].(string); ok {
+				msg.DeltaAction = deltaAction
+			}
+			if typeChange, ok := msgMap["type_change"].(bool); ok {
+				msg.TypeChange = typeChange
+			}
+			if groupID, ok := msgMap["group_id"].(string); ok {
+				msg.GroupID = groupID
+			}
+			if groupStart, ok := msgMap["group_start"].(bool); ok {
+				msg.GroupStart = groupStart
+			}
+			if groupEnd, ok := msgMap["group_end"].(bool); ok {
+				msg.GroupEnd = groupEnd
+			}
+
+			// Metadata (optional)
+			if metadataMap, ok := msgMap["metadata"].(map[string]interface{}); ok {
+				metadata := &message.Metadata{}
+				if timestamp, ok := metadataMap["timestamp"].(float64); ok {
+					metadata.Timestamp = int64(timestamp)
+				}
+				if sequence, ok := metadataMap["sequence"].(float64); ok {
+					metadata.Sequence = int(sequence)
+				}
+				if traceID, ok := metadataMap["trace_id"].(string); ok {
+					metadata.TraceID = traceID
+				}
+				msg.Metadata = metadata
+			}
+
+			group.Messages = append(group.Messages, msg)
+		}
+	} else {
+		return nil, fmt.Errorf("group.messages is required and must be an array")
+	}
+
+	// Metadata (optional)
+	if metadataMap, ok := groupMap["metadata"].(map[string]interface{}); ok {
+		metadata := &message.Metadata{}
+		if timestamp, ok := metadataMap["timestamp"].(float64); ok {
+			metadata.Timestamp = int64(timestamp)
+		}
+		if sequence, ok := metadataMap["sequence"].(float64); ok {
+			metadata.Sequence = int(sequence)
+		}
+		if traceID, ok := metadataMap["trace_id"].(string); ok {
+			metadata.TraceID = traceID
+		}
+		group.Metadata = metadata
+	}
+
+	return group, nil
+}
diff --git a/agent/output/jsapi/output_test.go b/agent/output/jsapi/output_test.go
new file mode 100644
index 00000000..535ec035
--- /dev/null
+++ b/agent/output/jsapi/output_test.go
@@ -0,0 +1,361 @@
+package jsapi
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	v8 "github.com/yaoapp/gou/runtime/v8"
+	agentContext "github.com/yaoapp/yao/agent/context"
+	"github.com/yaoapp/yao/config"
+	"github.com/yaoapp/yao/test"
+)
+
+func TestOutputConstructor(t *testing.T) {
+	test.Prepare(t, config.Conf)
+	defer test.Clean()
+
+	tests := []struct {
+		name        string
+		script      string
+		expectError bool
+	}{
+		{
+			name: "Create Output with context",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					return output !== undefined && output !== null;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Create Output without context should fail",
+			script: `
+				function test(ctx) {
+					try {
+						const output = new Output();
+						return false;
+					} catch (e) {
+						return e.toString().includes("context argument");
+					}
+				}
+			`,
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := agentContext.New(context.Background(), nil, "test-chat-123", "")
+			ctx.AssistantID = "test-assistant-456"
+
+			// Execute test script with v8.Call
+			res, err := v8.Call(v8.CallOptions{}, tt.script, &ctx)
+			if tt.expectError {
+				assert.Error(t, err)
+				return
+			}
+
+			assert.NoError(t, err)
+			assert.True(t, res.(bool))
+		})
+	}
+}
+
+func TestOutputSend(t *testing.T) {
+	test.Prepare(t, config.Conf)
+	defer test.Clean()
+
+	tests := []struct {
+		name        string
+		script      string
+		expectError bool
+		validate    func(*testing.T, *agentContext.Context)
+	}{
+		{
+			name: "Send text message with object",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					output.Send({ 
+						type: "text", 
+						props: { content: "Hello World" } 
+					});
+					return true;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send text message with string shorthand",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					output.Send("Hello World");
+					return true;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send message with all fields",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					output.Send({ 
+						type: "text", 
+						props: { content: "Test" },
+						id: "msg-1",
+						delta: true,
+						done: false,
+						delta_path: "content",
+						delta_action: "append",
+						metadata: {
+							timestamp: 1234567890,
+							sequence: 1,
+							trace_id: "trace-123"
+						}
+					});
+					return true;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send error message",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					output.Send({ 
+						type: "error", 
+						props: { 
+							message: "Something went wrong",
+							code: "ERR_001"
+						} 
+					});
+					return true;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send without message should fail",
+			script: `
+				function test(ctx) {
+					try {
+						const output = new Output(ctx);
+						output.Send();
+						return false;
+					} catch (e) {
+						return e.toString().includes("message argument");
+					}
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send message without type should fail",
+			script: `
+				function test(ctx) {
+					try {
+						const output = new Output(ctx);
+						output.Send({ props: { content: "test" } });
+						return false;
+					} catch (e) {
+						return e.toString().includes("type is required");
+					}
+				}
+			`,
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Create context with mock writer
+			ctx := agentContext.New(context.Background(), nil, "test-chat", "")
+			ctx.Writer = &mockWriter{}
+
+			// Execute test script with v8.Call
+			res, err := v8.Call(v8.CallOptions{}, tt.script, &ctx)
+			if tt.expectError {
+				assert.Error(t, err)
+				return
+			}
+
+			assert.NoError(t, err)
+			assert.True(t, res.(bool))
+
+			if tt.validate != nil {
+				tt.validate(t, &ctx)
+			}
+		})
+	}
+}
+
+func TestOutputSendGroup(t *testing.T) {
+	test.Prepare(t, config.Conf)
+	defer test.Clean()
+
+	tests := []struct {
+		name        string
+		script      string
+		expectError bool
+	}{
+		{
+			name: "Send message group",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					output.SendGroup({ 
+						id: "group-1",
+						messages: [
+							{ type: "text", props: { content: "Message 1" } },
+							{ type: "text", props: { content: "Message 2" } }
+						]
+					});
+					return true;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send group with metadata",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					output.SendGroup({ 
+						id: "group-1",
+						messages: [
+							{ type: "text", props: { content: "Test" } }
+						],
+						metadata: {
+							timestamp: 1234567890,
+							sequence: 1
+						}
+					});
+					return true;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send empty group",
+			script: `
+				function test(ctx) {
+					const output = new Output(ctx);
+					output.SendGroup({ 
+						id: "group-1",
+						messages: []
+					});
+					return true;
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send group without id should fail",
+			script: `
+				function test(ctx) {
+					try {
+						const output = new Output(ctx);
+						output.SendGroup({ 
+							messages: [
+								{ type: "text", props: { content: "Test" } }
+							]
+						});
+						return false;
+					} catch (e) {
+						return e.toString().includes("id is required");
+					}
+				}
+			`,
+			expectError: false,
+		},
+		{
+			name: "Send group without messages should fail",
+			script: `
+				function test(ctx) {
+					try {
+						const output = new Output(ctx);
+						output.SendGroup({ id: "group-1" });
+						return false;
+					} catch (e) {
+						return e.toString().includes("messages is required");
+					}
+				}
+			`,
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Create context with mock writer
+			ctx := agentContext.New(context.Background(), nil, "test-chat", "")
+			ctx.Writer = &mockWriter{}
+
+			// Execute test script with v8.Call
+			res, err := v8.Call(v8.CallOptions{}, tt.script, &ctx)
+			if tt.expectError {
+				assert.Error(t, err)
+				return
+			}
+
+			assert.NoError(t, err)
+			assert.True(t, res.(bool))
+		})
+	}
+}
+
+func TestOutputChaining(t *testing.T) {
+	test.Prepare(t, config.Conf)
+	defer test.Clean()
+
+	script := `
+		function test(ctx) {
+			const output = new Output(ctx);
+			
+			// Send should return the output object for chaining
+			const result = output.Send("Message 1");
+			
+			// Should be able to chain sends
+			output.Send("Message 2").Send("Message 3");
+			
+			return result !== undefined;
+		}
+	`
+
+	ctx := agentContext.New(context.Background(), nil, "test-chat", "")
+	ctx.Writer = &mockWriter{}
+
+	// Execute test script with v8.Call
+	res, err := v8.Call(v8.CallOptions{}, script, &ctx)
+	assert.NoError(t, err)
+	assert.True(t, res.(bool))
+}
+
+// mockWriter is a mock implementation of http.ResponseWriter for testing
+type mockWriter struct {
+	data   [][]byte
+	header http.Header
+}
+
+func (w *mockWriter) Header() http.Header {
+	if w.header == nil {
+		w.header = make(http.Header)
+	}
+	return w.header
+}
+
+func (w *mockWriter) Write(p []byte) (n int, err error) {
+	w.data = append(w.data, p)
+	return len(p), nil
+}
+
+func (w *mockWriter) WriteHeader(statusCode int) {}
+
+func (w *mockWriter) Flush() {}
diff --git a/main.go b/main.go
index 356fb79e..eb10398b 100644
--- a/main.go
+++ b/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	_ "github.com/yaoapp/gou/diff"
 	_ "github.com/yaoapp/gou/encoding"
+	_ "github.com/yaoapp/yao/agent/output/jsapi"
 	_ "github.com/yaoapp/yao/aigc"
 	_ "github.com/yaoapp/yao/crypto"
 	_ "github.com/yaoapp/yao/excel"