Enum SessionEvent 

#[non_exhaustive]
pub enum SessionEvent {
    Message {
        content: Vec<ContentBlock>,
        seq: u64,
    },
    ToolUse {
        tool_use_id: String,
        name: String,
        input: Value,
        seq: u64,
    },
    CustomToolUse {
        custom_tool_use_id: String,
        name: String,
        input: Value,
        seq: u64,
    },
    McpToolUse {
        tool_use_id: String,
        name: String,
        input: Value,
        seq: u64,
    },
    StatusRunning {
        seq: u64,
    },
    StatusIdle {
        seq: u64,
        stop_reason: Option<StopReason>,
        usage: Option<UsageReport>,
    },
    Error {
        code: String,
        message: String,
        seq: u64,
    },
}

Agent-to-client event. Each carries a monotonic seq per session.

Wire Shapes (CANON §3.4)

{"type": "agent.message", "content": [{"type": "text", "text": "Hi"}], "seq": 1}
{"type": "status.running", "seq": 2}
{"type": "status.idle", "seq": 3, "stop_reason": {"reason": "end_turn"}}

Example

use adk_managed::types::{SessionEvent, ContentBlock};

let event = SessionEvent::Message {
    content: vec![ContentBlock::Text { text: "Hello".to_string() }],
    seq: 1,
};
let json = serde_json::to_string(&event).unwrap();
assert!(json.contains(r#""type":"agent.message""#));
assert!(json.contains(r#""seq":1"#));

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Message

Assistant message content.

Fields

content: Vec<ContentBlock>

The message content blocks.

seq: u64

Monotonically increasing sequence number.

ToolUse

Built-in tool invocation (executes server-side in sandbox).

Fields

tool_use_id: String

Unique identifier for this tool use.

name: String

Tool name.

input: Value

Tool input parameters.

seq: u64

Monotonically increasing sequence number.

CustomToolUse

Custom tool invocation (client must execute and return result). The loop PARKS until user.custom_tool_result with matching ID arrives.

Fields

custom_tool_use_id: String

Unique identifier for this custom tool use.

name: String

Tool name.

input: Value

Tool input parameters.

seq: u64

Monotonically increasing sequence number.

McpToolUse

MCP tool invocation.

Fields

tool_use_id: String

Unique identifier for this MCP tool use.

name: String

Tool name.

input: Value

Tool input parameters.

seq: u64

Monotonically increasing sequence number.

StatusRunning

Session became active (processing a turn).

Fields

seq: u64

Monotonically increasing sequence number.

StatusIdle

Turn complete; awaiting next event. Includes stop_reason to tell the caller WHY the turn ended, and usage reporting token consumption for billing/metering.

Fields

seq: u64

Monotonically increasing sequence number.

stop_reason: Option<StopReason>

Why the turn ended. Enables the client to decide what to do next.

usage: Option<UsageReport>

Token usage for this turn (input/output/total). Present when the LLM reports usage metadata; None on error turns.

Error

Error during execution.

Fields

code: String

Error code identifier.

message: String

Human-readable error message.

seq: u64

Monotonically increasing sequence number.

Trait Implementations

impl Clone for SessionEvent

fn clone(&self) -> SessionEvent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SessionEvent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SessionEvent

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for SessionEvent

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.