DevUI - A Sample App for Running Agents and Workflows

A lightweight, standalone sample app interface for running entities (agents/workflows) in the Microsoft Agent Framework supporting directory-based discovery, in-memory entity registration, and sample entity gallery.

Important

DevUI is a sample app to help you get started with the Agent Framework. It is not intended for production use. For production, or for features beyond what is provided in this sample app, it is recommended that you build your own custom interface and API server using the Agent Framework SDK.

Quick Start

# Install
pip install agent-framework-devui --pre

You can also launch it programmatically

from agent_framework import ChatAgent
from agent_framework.openai import OpenAIChatClient
from agent_framework.devui import serve

def get_weather(location: str) -> str:
    """Get weather for a location."""
    return f"Weather in {location}: 72°F and sunny"

# Create your agent
agent = ChatAgent(
    name="WeatherAgent",
    chat_client=OpenAIChatClient(),
    tools=[get_weather]
)

# Launch debug UI - that's it!
serve(entities=[agent], auto_open=True)
# → Opens browser to http://localhost:8080

In addition, if you have agents/workflows defined in a specific directory structure (see below), you can launch DevUI from the cli to discover and run them.

# Launch web UI + API server
devui ./agents --port 8080
# → Web UI: http://localhost:8080
# → API: http://localhost:8080/v1/*

When DevUI starts with no discovered entities, it displays a sample entity gallery with curated examples from the Agent Framework repository. You can download these samples, review them, and run them locally to get started quickly.

Using MCP Tools

Important: Don't use async with context managers when creating agents with MCP tools for DevUI - connections will close before execution.

# ✅ Correct - DevUI handles cleanup automatically
mcp_tool = MCPStreamableHTTPTool(url="http://localhost:8011/mcp", chat_client=chat_client)
agent = ChatAgent(tools=mcp_tool)
serve(entities=[agent])

MCP tools use lazy initialization and connect automatically on first use. DevUI attempts to clean up connections on shutdown

Directory Structure

For your agents to be discovered by the DevUI, they must be organized in a directory structure like below. Each agent/workflow must have an __init__.py that exports the required variable (agent or workflow).

Note: .env files are optional but will be automatically loaded if present in the agent/workflow directory or parent entities directory. Use them to store API keys, configuration variables, and other environment-specific settings.

agents/
├── weather_agent/
│   ├── __init__.py      # Must export: agent = ChatAgent(...)
│   ├── agent.py
│   └── .env             # Optional: API keys, config vars
├── my_workflow/
│   ├── __init__.py      # Must export: workflow = WorkflowBuilder()...
│   ├── workflow.py
│   └── .env             # Optional: environment variables
└── .env                 # Optional: shared environment variables

Viewing Telemetry (Otel Traces) in DevUI

Agent Framework emits OpenTelemetry (Otel) traces for various operations. You can view these traces in DevUI by enabling tracing when starting the server.

devui ./agents --tracing framework

OpenAI-Compatible API

For convenience, DevUI provides an OpenAI Responses backend API. This means you can run the backend and also use the OpenAI client sdk to connect to it. Use agent/workflow name as the model, and set streaming to True as needed.

# Simple - use your entity name as the model
curl -X POST http://localhost:8080/v1/responses \
  -H "Content-Type: application/json" \
  -d @- << 'EOF'
{
  "model": "weather_agent",
  "input": "Hello world"
}

Or use the OpenAI Python SDK:

from openai import OpenAI

client = OpenAI(
    base_url="http://localhost:8080/v1",
    api_key="not-needed"  # API key not required for local DevUI
)

response = client.responses.create(
    model="weather_agent",  # Your agent/workflow name
    input="What's the weather in Seattle?"
)

# Extract text from response
print(response.output[0].content[0].text)
# Supports streaming with stream=True

Multi-turn Conversations

Use the standard OpenAI conversation parameter for multi-turn conversations:

# Create a conversation
conversation = client.conversations.create(
    metadata={"agent_id": "weather_agent"}
)

# Use it across multiple turns
response1 = client.responses.create(
    model="weather_agent",
    input="What's the weather in Seattle?",
    conversation=conversation.id
)

response2 = client.responses.create(
    model="weather_agent",
    input="How about tomorrow?",
    conversation=conversation.id  # Continues the conversation!
)

How it works: DevUI automatically retrieves the conversation's message history from the stored thread and passes it to the agent. You don't need to manually manage message history - just provide the same conversation ID for follow-up requests.

CLI Options

devui [directory] [options]

Options:
  --port, -p      Port (default: 8080)
  --host          Host (default: 127.0.0.1)
  --headless      API only, no UI
  --config        YAML config file
  --tracing       none|framework|workflow|all
  --reload        Enable auto-reload

Key Endpoints

API Mapping

Given that DevUI offers an OpenAI Responses API, it internally maps messages and events from Agent Framework to OpenAI Responses API events (in _mapper.py). For transparency, this mapping is shown below:

OpenAI Event/Type	Agent Framework Content	Status
	Lifecycle Events
`response.created` + `response.in_progress`	`AgentStartedEvent`	OpenAI
`response.completed`	`AgentCompletedEvent`	OpenAI
`response.failed`	`AgentFailedEvent`	OpenAI
`response.created` + `response.in_progress`	`WorkflowStartedEvent`	OpenAI
`response.completed`	`WorkflowCompletedEvent`	OpenAI
`response.failed`	`WorkflowFailedEvent`	OpenAI
	Content Types
`response.content_part.added` + `response.output_text.delta`	`TextContent`	OpenAI
`response.reasoning_text.delta`	`TextReasoningContent`	OpenAI
`response.output_item.added`	`FunctionCallContent` (initial)	OpenAI
`response.function_call_arguments.delta`	`FunctionCallContent` (args)	OpenAI
`response.function_result.complete`	`FunctionResultContent`	DevUI
`response.function_approval.requested`	`FunctionApprovalRequestContent`	DevUI
`response.function_approval.responded`	`FunctionApprovalResponseContent`	DevUI
`error`	`ErrorContent`	OpenAI
Final `Response.usage` field (not streamed)	`UsageContent`	OpenAI
	Workflow Events
`response.output_item.added` (ExecutorActionItem)*	`ExecutorInvokedEvent`	OpenAI
`response.output_item.done` (ExecutorActionItem)*	`ExecutorCompletedEvent`	OpenAI
`response.output_item.done` (ExecutorActionItem with error)*	`ExecutorFailedEvent`	OpenAI
`response.workflow_event.complete`	`WorkflowEvent` (other)	DevUI
`response.trace.complete`	`WorkflowStatusEvent`	DevUI
`response.trace.complete`	`WorkflowWarningEvent`	DevUI
	Trace Content
`response.trace.complete`	`DataContent`	DevUI
`response.trace.complete`	`UriContent`	DevUI
`response.trace.complete`	`HostedFileContent`	DevUI
`response.trace.complete`	`HostedVectorStoreContent`	DevUI

*Uses standard OpenAI event structure but carries DevUI-specific ExecutorActionItem payload

OpenAI = Standard OpenAI Responses API event types
DevUI = Custom event types specific to Agent Framework (e.g., workflows, traces, function approvals)

OpenAI Responses API Compliance

DevUI follows the OpenAI Responses API specification for maximum compatibility:

OpenAI Standard Event Types Used:

ResponseOutputItemAddedEvent - Output item notifications (function calls and results)
ResponseOutputItemDoneEvent - Output item completion notifications
Response.usage - Token usage (in final response, not streamed)
All standard text, reasoning, and function call events

Custom DevUI Extensions:

response.function_approval.requested - Function approval requests (for interactive approval workflows)
response.function_approval.responded - Function approval responses (user approval/rejection)
response.workflow_event.complete - Agent Framework workflow events
response.trace.complete - Execution traces and internal content (DataContent, UriContent, hosted files/stores)

These custom extensions are clearly namespaced and can be safely ignored by standard OpenAI clients. Note that DevUI also uses standard OpenAI events with custom payloads (e.g., ExecutorActionItem within response.output_item.added).

Entity Management

GET /v1/entities - List discovered agents/workflows
GET /v1/entities/{entity_id}/info - Get detailed entity information
POST /v1/entities/{entity_id}/reload - Hot reload entity (for development)

Execution (OpenAI Responses API)

POST /v1/responses - Execute agent/workflow (streaming or sync)

Conversations (OpenAI Standard)

POST /v1/conversations - Create conversation
GET /v1/conversations/{id} - Get conversation
POST /v1/conversations/{id} - Update conversation metadata
DELETE /v1/conversations/{id} - Delete conversation
GET /v1/conversations?agent_id={id} - List conversations (DevUI extension)
POST /v1/conversations/{id}/items - Add items to conversation
GET /v1/conversations/{id}/items - List conversation items
GET /v1/conversations/{id}/items/{item_id} - Get conversation item

Health

GET /health - Health check

Security

DevUI is designed as a sample application for local development and should not be exposed to untrusted networks or used in production environments.

Security features:

Only loads entities from local directories or in-memory registration
No remote code execution capabilities
Binds to localhost (127.0.0.1) by default
All samples must be manually downloaded and reviewed before running

Best practices:

Never expose DevUI to the internet
Review all agent/workflow code before running
Only load entities from trusted sources
Use .env files for sensitive credentials (never commit them)

Implementation

Discovery: agent_framework_devui/_discovery.py
Execution: agent_framework_devui/_executor.py
Message Mapping: agent_framework_devui/_mapper.py
Conversations: agent_framework_devui/_conversations.py
API Server: agent_framework_devui/_server.py
CLI: agent_framework_devui/_cli.py

Examples

See working implementations in python/samples/getting_started/devui/

License

MIT