Enum StreamEvent 

#[non_exhaustive]
pub enum StreamEvent {
    SystemInit {
        session_id: String,
        model: String,
    },
    Thinking(String),
    Text(String),
    AssistantThinking(String),
    AssistantText(String),
    ToolUse {
        id: String,
        name: String,
        input: Value,
    },
    ToolResult {
        tool_use_id: String,
        content: String,
    },
    RateLimit {
        resets_at: u64,
    },
    InputJsonDelta(String),
    SignatureDelta(String),
    CitationsDelta(Value),
    MessageStart {
        model: String,
        id: String,
    },
    ContentBlockStart {
        index: u64,
        block_type: String,
    },
    ContentBlockStop {
        index: u64,
    },
    MessageDelta {
        stop_reason: Option<String>,
    },
    MessageStop,
    Ping,
    Error {
        error_type: String,
        message: String,
    },
    Result(ClaudeResponse),
    Unknown(Value),
}

Available on crate feature stream only.

Event emitted from a stream-json response.

Events come from two sources:

• Delta variants (Text, Thinking, etc.) — real-time token-level chunks from stream_event. Requires crate::ClaudeConfigBuilder::include_partial_messages to be enabled.
• Assistant variants (AssistantText, AssistantThinking) — complete messages from assistant events. Always sent regardless of include_partial_messages.

When include_partial_messages is enabled, both delta and assistant variants are emitted. Use delta variants for real-time display and assistant variants for the final complete text.

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.

SystemInit

Session initialization info.

Fields

session_id: String

Session ID.

model: String

Model name.

Thinking(String)

Thinking delta chunk from real-time streaming (stream_event / thinking_delta).

Only emitted when crate::ClaudeConfigBuilder::include_partial_messages is enabled.

Text(String)

Text delta chunk from real-time streaming (stream_event / text_delta).

Only emitted when crate::ClaudeConfigBuilder::include_partial_messages is enabled.

AssistantThinking(String)

Complete thinking text from assistant event. Always emitted.

AssistantText(String)

Complete text from assistant event. Always emitted.

ToolUse

Tool invocation by the model.

Fields

id: String

Tool use ID.

name: String

Tool name.

input: Value

Tool input as JSON value.

ToolResult

Tool execution result.

Fields

tool_use_id: String

ID of the tool use this result belongs to.

content: String

Result content.

RateLimit

Rate limit information.

Fields

resets_at: u64

Timestamp when the rate limit resets.

InputJsonDelta(String)

Partial tool input JSON chunk (from input_json_delta).

SignatureDelta(String)

Thinking signature chunk (from signature_delta).

CitationsDelta(Value)

Citations chunk (from citations_delta).

MessageStart

Start of a message (from message_start).

Fields

model: String

Model name.

id: String

Message ID.

ContentBlockStart

Start of a content block (from content_block_start).

Fields

index: u64

Block index.

block_type: String

Block type ("text", "thinking", "tool_use", etc.).

ContentBlockStop

End of a content block (from content_block_stop).

Fields

index: u64

Block index.

MessageDelta

Message-level delta with stop reason (from message_delta).

Fields

stop_reason: Option<String>

Why the message stopped.

MessageStop

Message complete (from message_stop).

Ping

Keepalive ping (from ping).

Error

API error event (from error).

Fields

error_type: String

Error type.

message: String

Error message.

Result(ClaudeResponse)

Final result (same structure as non-streaming response).

Unknown(Value)

Unrecognized event (raw JSON preserved so nothing is lost).

Trait Implementations

impl Clone for StreamEvent

fn clone(&self) -> StreamEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StreamEvent

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

Formats the value using the given formatter.