The four shapes
agent_swap: hand off to another node
Moves control to another node in the topology. This is how a graph is built: every edge on the canvas is anagent_swap tool, and its description tells the model when to take the path. See Agents and topology.
end_call: end the conversation
Ends the conversation when the caller’s goal is complete. The engine closes the turn loop.custom: call your deployed code
Calls a handler your organization has deployed to Gradient. The engine runs it, appends the result to the transcript, and calls the model again on the same node. Authoring and deploying are covered in Custom tools.Attaching a custom tool floats the node’s draft to the latest deployed version of that tool. Publishing the agent pins the exact version, so redeploying the tool later never silently changes an agent already serving traffic.
http_req: a declarative external request
Makes an HTTP request defined entirely by the tool’s config, with no code to deploy. The config is a small object:method defaults to GET. The engine performs the request and returns the response status and body into the turn. The model can pass optional per-call overrides, though most http_req tools need none.
Attaching tools to a node
Open a node in the builder and add tools to it. A custom tool must be deployed before it can be attached. Every tool is a row on the node, so it travels with the node when you publish; a published version calls exactly the tools it was published with.Custom tools
Author, deploy, and invoke your own code as tools the engine calls.
Knowledge and skills
Attach searchable documents and reusable instructions to a node.