Enum ModelStreamEvent 

pub enum ModelStreamEvent {
    TextDelta {
        text: String,
    },
    ThinkingDelta {
        text: String,
    },
    Status {
        label: String,
    },
    Usage {
        input_tokens: Option<u64>,
        output_tokens: Option<u64>,
        cache_creation_tokens: Option<u64>,
        cache_read_tokens: Option<u64>,
    },
    ToolCall(ToolInvocation),
    ToolCallProgress {
        id: Option<String>,
        tool_name: String,
        arguments_chars: usize,
    },
    Done,
}

A single event from a model provider’s streaming response.

Variants

TextDelta

An incremental text delta from the assistant.

Fields

text: String

The incremental text content.

ThinkingDelta

An incremental thinking/reasoning delta.

Fields

text: String

The incremental thinking content.

Status

A status message from the provider (e.g. “processing”, “queued”).

Fields

label: String

Human-readable status label.

Usage

Token usage information reported by the provider.

Fields

input_tokens: Option<u64>

Number of input/prompt tokens consumed, if reported.

output_tokens: Option<u64>

Number of output/completion tokens produced, if reported.

cache_creation_tokens: Option<u64>

Number of tokens written to the prompt cache (Anthropic).

cache_read_tokens: Option<u64>

Number of tokens read from the prompt cache (Anthropic).

ToolCall(ToolInvocation)

The model requested a tool invocation.

ToolCallProgress

The model is streaming a tool call (name known; arguments may still be incomplete).

Providers emit this while native tool-call arguments are being generated so clients can show progress instead of a false “waiting for model” idle.

Fields

id: Option<String>

Provider tool-call id when known.

tool_name: String

Tool name when known (empty only until the first name chunk arrives).

arguments_chars: usize

Total characters of arguments streamed so far for this call.

Done

The stream has ended.

Trait Implementations

impl Clone for ModelStreamEvent

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ModelStreamEvent

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ModelStreamEvent

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ModelStreamEvent

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for ModelStreamEvent

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ModelStreamEvent