Enum StreamPart 

pub enum StreamPart {
    TextStart {
        id: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    TextDelta {
        id: String,
        delta: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    TextEnd {
        id: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    ReasoningStart {
        id: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    ReasoningDelta {
        id: String,
        delta: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    ReasoningEnd {
        id: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    ToolInputStart {
        id: String,
        tool_name: String,
        provider_executed: Option<bool>,
        dynamic: Option<bool>,
        title: Option<String>,
        provider_metadata: Option<ProviderMetadata>,
    },
    ToolInputDelta {
        id: String,
        delta: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    ToolInputEnd {
        id: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    ToolApprovalRequest(ToolApprovalRequest),
    ToolCall(ToolCallPart),
    ToolResult(ToolResult),
    Custom {
        kind: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    Source(Source),
    File(FilePart),
    ReasoningFile {
        data: FileData,
        media_type: String,
        provider_metadata: Option<ProviderMetadata>,
    },
    StreamStart {
        warnings: Vec<Warning>,
    },
    ResponseMetadata(ResponseMetadata),
    Finish {
        usage: Usage,
        finish_reason: FinishReason,
        provider_metadata: Option<ProviderMetadata>,
    },
    Raw {
        raw_value: JsonValue,
    },
    Error {
        error: JsonValue,
    },
}

One unit emitted on the stream returned by super::LanguageModel::do_stream.

Variants

TextStart

Start of a text block.

Fields

id: String

Block id (used to correlate text-delta / text-end).

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

TextDelta

Incremental text fragment.

Fields

id: String

Block id.

delta: String

Text fragment.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

TextEnd

End of a text block.

Fields

id: String

Block id.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

ReasoningStart

Start of a reasoning block.

Fields

id: String

Block id.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

ReasoningDelta

Incremental reasoning fragment.

Fields

id: String

Block id.

delta: String

Reasoning fragment.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

ReasoningEnd

End of a reasoning block.

Fields

id: String

Block id.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

ToolInputStart

Start of a tool input being streamed.

Fields

id: String

Tool call id.

tool_name: String

Tool name.

provider_executed: Option<bool>

true if executed by the provider.

dynamic: Option<bool>

true if defined at runtime.

title: Option<String>

Optional display title.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

ToolInputDelta

Streamed chunk of a tool’s input JSON.

Fields

id: String

Tool call id.

delta: String

JSON fragment.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

ToolInputEnd

End of a tool’s input stream.

Fields

id: String

Tool call id.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

ToolApprovalRequest(ToolApprovalRequest)

Approval requested for a provider-executed tool call.

ToolCall(ToolCallPart)

Final tool call with assembled input.

ToolResult(ToolResult)

Tool result emitted by a provider-executed tool.

Custom

Provider-specific custom content.

Fields

kind: String

Custom kind tag, e.g. "openai.web_search_result".

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

Source(Source)

Citation / grounding source.

File(FilePart)

File generated by the model (mid-stream emission).

Mirrors ai-sdk’s LanguageModelV4File stream part. The wire tag is "file" and shape matches a FilePart (filename / data / media type / provider options).

ReasoningFile

File generated as part of a reasoning trace (mid-stream emission).

Mirrors ai-sdk’s LanguageModelV4ReasoningFile stream part. Wire tag is "reasoning-file".

Fields

data: FileData

File payload.

media_type: String

IANA media type.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

StreamStart

Stream-start metadata.

Fields

warnings: Vec<Warning>

Warnings for the call.

ResponseMetadata(ResponseMetadata)

Response-level metadata available mid-stream.

Finish

Terminal frame with totals.

Fields

usage: Usage

Final token usage.

finish_reason: FinishReason

Why the model stopped.

provider_metadata: Option<ProviderMetadata>

Provider-specific metadata.

Raw

Raw provider chunk (only when include_raw_chunks is set).

Fields

raw_value: JsonValue

Provider-native value.

Error

In-stream error from the provider.

The stream is still alive; the outer Result is Ok.

Fields

error: JsonValue

Error payload as provided by the upstream.

Trait Implementations

impl Clone for StreamPart

fn clone(&self) -> StreamPart

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StreamPart

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for StreamPart

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for StreamPart

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for StreamPart

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 StreamPart