Module message 

A2UI protocol envelopes.

A2UI is a stream of JSON objects in two directions. Each object carries a version discriminator plus exactly one payload key:

Direction	Payload keys
agent → renderer	createSurface, updateComponents, updateDataModel, deleteSurface, callRendererFunction, agentFunctionResponse
renderer → agent	action, callAgentFunction, rendererFunctionResponse, error

The adjacency-list component model

Components are sent as a flat list. Parent/child links are ID references, never nesting — a Card names its child by id, a Column holds an array of ids. The renderer stores every component in a map and rebuilds the tree at render time, which is what lets the agent stream definitions in any order and lets the renderer start painting as soon as root arrives.

use ag_ui_a2ui::message::{AgentMessage, Component};
use serde_json::json;

let msg = AgentMessage::update_components(
    "profile",
    vec![
        Component::new("root", "Column").with("children", json!(["name"])),
        Component::new("name", "Text").with("text", json!("Ada")),
    ],
);
let wire = serde_json::to_value(&msg).unwrap();
assert_eq!(wire["version"], "v0.9");
assert_eq!(wire["updateComponents"]["components"][0]["component"], "Column");

Structs

Action

Payload of an action message.

AgentMessage

One agent → renderer message.

CallAgentFunction

Payload of a callAgentFunction message.

CallRendererFunction

Payload of a callRendererFunction message.

ChildTemplate

The template form of a ChildList.

Component

One node of the flat component adjacency list.

CreateSurface

Payload of a createSurface message.

DeleteSurface

Payload of a deleteSurface message.

FunctionCall

A named function invocation, used both in component properties and in the two call*Function messages.

FunctionResponse

The result of a call*Function, sent back by whichever side ran it.

RendererError

Payload of an error message from the renderer.

RendererMessage

One renderer → agent message.

UpdateComponents

Payload of an updateComponents message.

UpdateDataModel

Payload of an updateDataModel message.

Enums

AgentPayload

The payload of an AgentMessage, externally tagged by its wire key.

ChildList

How a component declares its children.

RendererPayload

The payload of a RendererMessage, externally tagged by its wire key.

Functions

apply_data_model_update

Applies one updateDataModel operation to model.