The dev UI, the CLI and a server
Everything so far ran inside a Python script. ADK ships three other ways to run the same agent, and each one is a single command.
adk --helpUsage: adk [OPTIONS] COMMAND [ARGS]... Agent Development Kit CLI tools. Commands: api_server Starts a FastAPI server for agents. create Creates a new app in the current folder with prepopulated... deploy Deploys agent to hosted environments. eval Evaluates an agent given the eval sets. run Runs an agent. web Starts a FastAPI server with Web UI for agents.
That is the real output, trimmed to the commands worth knowing on day one. All of them need the layout from lesson 1: a folder with an agent.py that has a variable called root_agent.
The three you will use
| Command | What it gives you |
|---|---|
adk run my_agent | A conversation in your terminal |
adk web | A browser interface, with the events of each run laid out |
adk api_server | An HTTP server, so something else can call your agent |
The web one is the one to try first. It shows the same events you have been printing since lesson 6, but as a tree you can click through, which makes a multi-agent run much easier to follow than a wall of text.
Why the server matters
api_server is what turns an agent into something a product can use. It is the same agent, the same sessions and the same state, reachable over HTTP instead of from a Python file. Nothing about your code changes.
my_agent/
agent.py # root_agent lives here
.env # keys, for a real model
__init__.pyThe other commands are for later: eval runs test sets against an agent, and deploy pushes it to Cloud Run, GKE or the managed runtime. Both have their own sections in the documentation, and neither changes how the agent is written.
adk web at the agent you built in part 4 and open the event view. Watching a transfer happen in a tree is the fastest way to understand what the parts of this course actually do together.- Put one of your agents in an
agent.pyand runadk runagainst it. - Start
adk weband click through the events of a sequential agent.
This is what real progress feels like.