AIMessagePart 0.4.0 API

```
public final class AIMessagePart

                    
```
One step an AI agent took while replying, such as a round of reasoning or a tool call.
The agent writes each step as a custom attachment on its reply (ai_reasoning, ai_tool_call), and the order of the attachments is the order of the steps. The final answer stays in the message text and is shown after them.
The kinds of step are open: a new one can appear without breaking your code. Read the ones you know through their typed views (reasoning, toolCall), read kinds of your own from payload, and give anything else a neutral fallback (AIMessagePartItem shows a placeholder). Decoding is lenient: missing fields get defaults, and a step newer than this SDK understands keeps its payload but has no typed view.
```
// Stream Chat Android moves an attachment's `name` out of `extraData`, so put it back.
val parts = AIMessagePart.parts(
    message.attachments.map { it.type.orEmpty() to it.extraData + ("name" to it.name) },
)
for (part in parts) {
    part.reasoning?.let { /* … */}
    part.toolCall?.let { /* … */}
    if (part.kind == AIMessagePart.Kind("ai_citation")) { /* read part.payload */}
}
```

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`public final class`	`AIMessagePart.Kind`	What kind of step a part is. It is an open set: compare against the kinds you know and give the rest a fallback.
`public class`	`AIMessagePart.Companion`

Field Summary

Fields
Modifier and Type	Field	Description
`private final Boolean`	`isSupported`
`private final AIMessagePart.Kind`	`kind`
`private final String`	`id`
`private final Integer`	`version`
`private final Map<String, Object>`	`payload`
`private final AIReasoningPart`	`reasoning`
`private final AIToolCallPart`	`toolCall`

Method Summary

Modifier and Type	Method	Description
`final Boolean`	`getIsSupported()`
`final AIMessagePart.Kind`	`getKind()`	What kind of step this is.
`final String`	`getId()`	The step's stable identity, for diffing and animating while it streams.
`final Integer`	`getVersion()`	The step's format version (`v`).
`final Map<String, Object>`	`getPayload()`	The step's attachment payload, for kinds of your own or fields this SDK does not read.
`final AIReasoningPart`	`getReasoning()`	The step as a round of reasoning, when it is one this SDK can read.
`final AIToolCallPart`	`getToolCall()`	The step as a tool call, when it is one this SDK can read.
`Boolean`	`equals(Object other)`
`Integer`	`hashCode()`
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - getIsSupported
```
 final Boolean getIsSupported()
```
  - getKind
```
 final AIMessagePart.Kind getKind()
```
    What kind of step this is.
  - getId
```
 final String getId()
```
    The step's stable identity, for diffing and animating while it streams. Tool calls use the model provider's tool-call ID.
  - getVersion
```
 final Integer getVersion()
```
    The step's format version (v). It changes only when a kind changes incompatibly.
  - getPayload
```
 final Map<String, Object> getPayload()
```
    The step's attachment payload, for kinds of your own or fields this SDK does not read.
  - getReasoning
```
 final AIReasoningPart getReasoning()
```
    The step as a round of reasoning, when it is one this SDK can read.
  - getToolCall
```
 final AIToolCallPart getToolCall()
```
    The step as a tool call, when it is one this SDK can read.
  - equals
```
 Boolean equals(Object other)
```
  - hashCode
```
 Integer hashCode()
```
  - toString
```
 String toString()
```