`streamText()`

Streams text generations from a language model.

You can use the streamText function for interactive use cases such as chat bots and other real-time applications. You can also generate UI components with tools.

import { streamText } from 'ai';

const { textStream } = streamText({
  model: "xai/grok-4.5",
  prompt: 'Invent a new holiday and describe its traditions.',
});

for await (const textPart of textStream) {
  process.stdout.write(textPart);
}

For guidance on runtimeContext, toolsContext, tool context, and sensitive context filtering, see Runtime and Tool Context.

To see streamText in action, check out these examples.

Import

import { streamText } from "ai"

API Signature

model:

LanguageModel

instructions:

Instructions

prompt:

string | Array<SystemModelMessage | UserModelMessage | AssistantModelMessage | ToolModelMessage>

messages:

Array<SystemModelMessage | UserModelMessage | AssistantModelMessage | ToolModelMessage>

SystemModelMessage

role:

'system'

content:

string

UserModelMessage

role:

'user'

content:

string | Array<TextPart | ImagePart | FilePart>

TextPart

type:

'text'

text:

string

ImagePart

type:

'image'

image:

string | Uint8Array | Buffer | ArrayBuffer | URL

mediaType?:

string

FilePart

type:

'file'

data:

string | Uint8Array | Buffer | ArrayBuffer | URL

mediaType:

string

AssistantModelMessage

role:

'assistant'

content:

TextPart

type:

'text'

text:

string

ReasoningPart

type:

'reasoning'

text:

string

ReasoningFilePart

type:

'reasoning-file'

data:

string | Uint8Array | Buffer | ArrayBuffer | URL

mediaType:

string

FilePart

type:

'file'

data:

string | Uint8Array | Buffer | ArrayBuffer | URL

mediaType:

string

filename?:

string

ToolCallPart

type:

'tool-call'

toolCallId:

string

toolName:

string

input:

object based on zod schema

ToolModelMessage

role:

'tool'

content:

Array<ToolResultPart>

ToolResultPart

type:

'tool-result'

toolCallId:

string

toolName:

string

result:

unknown

isError?:

boolean

allowSystemInMessages?:

boolean

tools:

ToolSet

Tool

description?:

string | ((options: { context: CONTEXT; experimental_sandbox?: Experimental_SandboxSession }) => string)

inputSchema:

Zod Schema | JSON Schema

execute?:

async (parameters: T, options: ToolExecutionOptions) => RESULT

ToolExecutionOptions

toolCallId:

string

messages:

ModelMessage[]

abortSignal:

AbortSignal

toolChoice?:

"auto" | "none" | "required" | { "type": "tool", "toolName": string }

maxOutputTokens?:

number

temperature?:

number

topP?:

number

topK?:

number

presencePenalty?:

number

frequencyPenalty?:

number

stopSequences?:

string[]

seed?:

number

reasoning?:

maxRetries?:

number

abortSignal?:

AbortSignal

timeout?:

number | { totalMs?: number; stepMs?: number; chunkMs?: number; toolMs?: number; tools?: { [toolName]Ms?: number } }

headers?:

Record<string, string | undefined>

telemetry?:

TelemetryOptions

isEnabled?:

boolean

recordInputs?:

boolean

recordOutputs?:

boolean

functionId?:

string

includeRuntimeContext?:

{ [KEY in keyof CONTEXT]?: boolean }

includeToolsContext?:

{ [TOOL_NAME in keyof InferToolSetContext<TOOLS>]?: { [KEY in keyof InferToolSetContext<TOOLS>[TOOL_NAME]]?: boolean } }

integrations?:

Telemetry | Telemetry[]

experimental_transform?:

StreamTextTransform | Array<StreamTextTransform>

StreamTextTransform

transform:

(options: TransformOptions) => TransformStream<TextStreamPart<TOOLS>, TextStreamPart<TOOLS>>

TransformOptions

stopStream:

() => void

tools:

TOOLS

includeRawChunks?:

boolean

providerOptions?:

Record<string,JSONObject> | undefined

activeTools?:

ActiveTools<TOOLS>

toolOrder?:

ToolOrder<TOOLS>

toolApproval?:

ToolApprovalConfiguration<TOOLS, RUNTIME_CONTEXT>

experimental_refineToolInput?:

ToolInputRefinement<TOOLS>

stopWhen?:

StopCondition<TOOLS> | Array<StopCondition<TOOLS>>

prepareStep?:

(options: PrepareStepOptions) => PrepareStepResult<TOOLS> | Promise<PrepareStepResult<TOOLS>>

PrepareStepFunction<TOOLS>

options:

object

PrepareStepOptions

steps:

Array<StepResult<TOOLS>>

stepNumber:

number

model:

LanguageModel

instructions:

Instructions | undefined

initialInstructions:

Instructions | undefined

messages:

Array<ModelMessage>

runtimeContext?:

CONTEXT

toolsContext:

InferToolSetContext<TOOLS>

experimental_sandbox?:

Experimental_SandboxSession | undefined

PrepareStepResult<TOOLS>

model?:

LanguageModel

toolChoice?:

ToolChoice<TOOLS>

activeTools?:

ActiveTools<TOOLS>

toolOrder?:

ToolOrder<TOOLS>

instructions?:

Instructions

messages?:

Array<ModelMessage>

runtimeContext?:

CONTEXT

toolsContext:

InferToolSetContext<TOOLS>

experimental_sandbox?:

Experimental_SandboxSession

providerOptions?:

ProviderOptions

runtimeContext?:

CONTEXT

toolsContext:

InferToolSetContext<TOOLS>

experimental_sandbox?:

Experimental_SandboxSession

experimental_download?:

(requestedDownloads: Array<{ url: URL; isUrlSupportedByModel: boolean }>) => Promise<Array<null | { data: Uint8Array; mediaType?: string }>>

include?:

{ requestBody?: boolean; requestMessages?: boolean; rawChunks?: boolean }

Object

requestBody?:

boolean

requestMessages?:

boolean

rawChunks?:

boolean

repairToolCall?:

(options: ToolCallRepairOptions) => Promise<LanguageModelV4ToolCall | null>

ToolCallRepairOptions

instructions:

Instructions | undefined

system?:

Instructions | undefined

messages:

ModelMessage[]

toolCall:

LanguageModelV4ToolCall

tools:

TOOLS

inputSchema:

(options: { toolName: string }) => JSONSchema7

error:

NoSuchToolError | InvalidToolInputError

onChunk?:

(event: OnChunkResult) => Promise<void> |void

OnChunkResult

chunk:

TextStreamPart<TOOLS>

TextStreamPart

type:

'text-delta'

text:

string

TextStreamPart

type:

'reasoning-delta'

text:

string

TextStreamPart

type:

'source'

source:

Source

TextStreamPart

type:

'custom'

kind:

string

providerMetadata?:

ProviderMetadata

TextStreamPart

type:

'tool-call'

toolCallId:

string

toolName:

string

input:

object based on zod schema

TextStreamPart

type:

'tool-input-start'

id:

string

toolName:

string

TextStreamPart

type:

'tool-input-delta'

id:

string

toolName:

string

delta:

string

TextStreamPart

type:

'tool-result'

toolCallId:

string

toolName:

string

input:

object based on zod schema

output:

any

onError?:

(event: OnErrorResult) => Promise<void> |void

OnErrorResult

error:

unknown

output?:

Output

Output.text():

Output

Output.object():

Output

Options

schema:

Schema<OBJECT>

name?:

string

description?:

string

Output.array():

Output

Options

element:

Schema<ELEMENT>

name?:

string

description?:

string

Output.choice():

Output

Options

options:

Array<string>

name?:

string

description?:

string

Output.json():

Output

Options

name?:

string

description?:

string

onStepEnd?:

(result: StepResult<TOOLS>) => Promise<void> | void

StepResult

stepType:

"initial" | "continue" | "tool-result"

finishReason:

rawFinishReason:

string | undefined

usage:

LanguageModelUsage

inputTokens:

number | undefined

inputTokenDetails:

LanguageModelInputTokenDetails

noCacheTokens:

number | undefined

cacheReadTokens:

number | undefined

cacheWriteTokens:

number | undefined

outputTokens:

number | undefined

outputTokenDetails:

LanguageModelOutputTokenDetails

textTokens:

number | undefined

reasoningTokens:

number | undefined

totalTokens:

number | undefined

raw?:

object | undefined

performance:

StepResultPerformance

effectiveOutputTokensPerSecond:

number

outputTokensPerSecond:

number | undefined

inputTokensPerSecond:

number | undefined

effectiveTotalTokensPerSecond:

number

stepTimeMs:

number

responseTimeMs:

number

toolExecutionMs:

Readonly<Record<string, number>>

timeToFirstOutputMs:

number | undefined

timeBetweenOutputChunksMs:

OutputChunkTimingStats | undefined

text:

string

reasoningText:

string | undefined

sources:

Array<Source>

Source

sourceType:

'url'

id:

string

url:

string

title?:

string

providerMetadata?:

SharedV2ProviderMetadata

files:

Array<GeneratedFile>

GeneratedFile

base64:

string

uint8Array:

Uint8Array

mediaType:

string

toolCalls:

ToolCall[]

toolResults:

ToolResult[]

warnings:

Warning[] | undefined

response?:

Response

id:

string

modelId:

string

timestamp:

Date

headers?:

Record<string, string>

isContinued:

boolean

providerMetadata?:

Record<string,JSONObject> | undefined

onStepFinish?:

GenerateTextOnStepFinishCallback<TOOLS>

onEnd?:

(result: OnEndResult) => Promise<void> | void

OnEndResult

finishReason:

rawFinishReason:

string | undefined

usage:

LanguageModelUsage

inputTokens:

number | undefined

inputTokenDetails:

LanguageModelInputTokenDetails

noCacheTokens:

number | undefined

cacheReadTokens:

number | undefined

cacheWriteTokens:

number | undefined

outputTokens:

number | undefined

outputTokenDetails:

LanguageModelOutputTokenDetails

textTokens:

number | undefined

reasoningTokens:

number | undefined

totalTokens:

number | undefined

raw?:

object | undefined

totalUsage:

LanguageModelUsage

inputTokens:

number | undefined

outputTokens:

number | undefined

totalTokens:

number | undefined

providerMetadata:

Record<string,JSONObject> | undefined

text:

string

reasoning:

string | undefined

reasoning:

Array<ReasoningDetail>

ReasoningDetail

type:

'text'

text:

string

signature?:

string

ReasoningDetail

type:

'redacted'

data:

string

sources:

Array<Source>

Source

sourceType:

'url'

id:

string

url:

string

title?:

string

providerMetadata?:

SharedV2ProviderMetadata

files:

Array<GeneratedFile>

GeneratedFile

base64:

string

uint8Array:

Uint8Array

mediaType:

string

toolCalls:

ToolCall[]

toolResults:

ToolResult[]

warnings:

Warning[] | undefined

response?:

Response

id:

string

modelId:

string

timestamp:

Date

headers?:

Record<string, string>

messages:

Array<ResponseMessage>

steps:

Array<StepResult>

finalStep:

StepResult

runtimeContext:

CONTEXT

onFinish?:

(result: OnEndResult) => Promise<void> | void

onAbort?:

(event: OnAbortResult) => Promise<void> | void

OnAbortResult

steps:

Array<StepResult>

onStart?:

(event: GenerateTextStartEvent) => PromiseLike<void> | void

GenerateTextStartEvent

provider:

string

modelId:

string

instructions:

Instructions | undefined

messages:

Array<ModelMessage>

tools:

TOOLS | undefined

toolChoice:

ToolChoice<TOOLS> | undefined

activeTools:

ActiveTools<TOOLS>

toolOrder:

ToolOrder<TOOLS>

maxOutputTokens:

number | undefined

temperature:

number | undefined

topP:

number | undefined

topK:

number | undefined

presencePenalty:

number | undefined

frequencyPenalty:

number | undefined

stopSequences:

string[] | undefined

seed:

number | undefined

maxRetries:

number

timeout:

number | { totalMs?: number; stepMs?: number; chunkMs?: number } | undefined

headers:

Record<string, string | undefined> | undefined

providerOptions:

ProviderOptions | undefined

output:

OUTPUT | undefined

abortSignal:

AbortSignal | undefined

include:

{ requestBody?: boolean; requestMessages?: boolean } | undefined

runtimeContext:

CONTEXT

toolsContext:

InferToolSetContext<TOOLS>

onStepStart?:

(event: GenerateTextStepStartEvent) => PromiseLike<void> | void

GenerateTextStepStartEvent

stepNumber:

number

provider:

string

modelId:

string

instructions:

Instructions | undefined

messages:

Array<ModelMessage>

tools:

TOOLS | undefined

toolChoice:

LanguageModelV4ToolChoice | undefined

activeTools:

ActiveTools<TOOLS>

toolOrder:

ToolOrder<TOOLS>

steps:

ReadonlyArray<StepResult<TOOLS>>

providerOptions:

ProviderOptions | undefined

timeout:

number | { totalMs?: number; stepMs?: number; chunkMs?: number } | undefined

headers:

Record<string, string | undefined> | undefined

stopWhen:

StopCondition<TOOLS> | Array<StopCondition<TOOLS>> | undefined

output:

OUTPUT | undefined

abortSignal:

AbortSignal | undefined

include:

{ requestBody?: boolean; requestMessages?: boolean } | undefined

runtimeContext:

CONTEXT

toolsContext:

InferToolSetContext<TOOLS>

onLanguageModelCallStart?:

(event: LanguageModelCallStartEvent) => PromiseLike<void> | void

LanguageModelCallStartEvent

callId:

string

provider:

string

modelId:

string

instructions:

Instructions | undefined

messages:

Array<ModelMessage>

tools:

ReadonlyArray<Record<string, unknown>> | undefined

onLanguageModelCallEnd?:

(event: LanguageModelCallEndEvent) => PromiseLike<void> | void

LanguageModelCallEndEvent

callId:

string

provider:

string

modelId:

string

finishReason:

FinishReason

usage:

LanguageModelUsage

content:

ReadonlyArray<ContentPart<TOOLS>>

responseId:

string

performance:

{ responseTimeMs: number; effectiveOutputTokensPerSecond: number; outputTokensPerSecond: number | undefined; inputTokensPerSecond: number | undefined; effectiveTotalTokensPerSecond: number; timeToFirstOutputMs: number | undefined; timeBetweenOutputChunksMs?: OutputChunkTimingStats }

LanguageModelCallPerformance

responseTimeMs:

number

effectiveOutputTokensPerSecond:

number

outputTokensPerSecond:

number | undefined

inputTokensPerSecond:

number | undefined

effectiveTotalTokensPerSecond:

number

timeToFirstOutputMs:

number | undefined

timeBetweenOutputChunksMs:

OutputChunkTimingStats | undefined

onToolExecutionStart?:

(event: ToolExecutionStartEvent) => PromiseLike<void> | void

ToolExecutionStartEvent

callId:

string

toolCall:

TypedToolCall<TOOLS>

messages:

Array<ModelMessage>

toolContext:

InferToolContext<TOOLS[toolName]>

onToolExecutionEnd?:

(event: ToolExecutionEndEvent) => PromiseLike<void> | void

ToolExecutionEndEvent

callId:

string

toolCall:

TypedToolCall<TOOLS>

toolExecutionMs:

number

messages:

Array<ModelMessage>

toolContext:

InferToolContext<TOOLS[toolName]>

toolOutput:

ToolOutput<TOOLS>

experimental_onToolCallStart?:

(event: ToolExecutionStartEvent) => PromiseLike<void> | void

experimental_onToolCallFinish?:

(event: ToolExecutionEndEvent) => PromiseLike<void> | void

Returns

content:

Promise<Array<ContentPart<TOOLS>>>

finishReason:

rawFinishReason:

PromiseLike<string | undefined>

usage:

Promise<LanguageModelUsage>

LanguageModelUsage

inputTokens:

number | undefined

outputTokens:

number | undefined

totalTokens:

number | undefined

totalUsage:

Promise<LanguageModelUsage>

LanguageModelUsage

inputTokens:

number | undefined

inputTokenDetails:

LanguageModelInputTokenDetails

noCacheTokens:

number | undefined

cacheReadTokens:

number | undefined

cacheWriteTokens:

number | undefined

outputTokens:

number | undefined

outputTokenDetails:

LanguageModelOutputTokenDetails

textTokens:

number | undefined

reasoningTokens:

number | undefined

totalTokens:

number | undefined

raw?:

object | undefined

providerMetadata:

Promise<ProviderMetadata | undefined>

text:

Promise<string>

reasoning:

Promise<Array<ReasoningOutput | ReasoningFileOutput>>

ReasoningOutput

type:

'reasoning'

text:

string

providerMetadata?:

SharedV2ProviderMetadata

ReasoningFileOutput

type:

'reasoning-file'

file:

GeneratedFile

providerMetadata?:

SharedV2ProviderMetadata

reasoningText:

Promise<string | undefined>

sources:

Promise<Array<Source>>

Source

sourceType:

'url'

id:

string

url:

string

title?:

string

providerMetadata?:

SharedV2ProviderMetadata

files:

Promise<Array<GeneratedFile>>

GeneratedFile

base64:

string

uint8Array:

Uint8Array

mediaType:

string

toolCalls:

Promise<TypedToolCall<TOOLS>[]>

toolResults:

Promise<TypedToolResult<TOOLS>[]>

staticToolCalls:

PromiseLike<Array<StaticToolCall<TOOLS>>>

dynamicToolCalls:

PromiseLike<Array<DynamicToolCall>>

staticToolResults:

PromiseLike<Array<StaticToolResult<TOOLS>>>

dynamicToolResults:

PromiseLike<Array<DynamicToolResult>>

request:

Promise<LanguageModelRequestMetadata>

LanguageModelRequestMetadata

messages?:

Array<ModelMessage>

body?:

unknown

response:

Promise<LanguageModelResponseMetadata>

LanguageModelResponseMetadata

id:

string

modelId:

string

timestamp:

Date

headers?:

Record<string, string>

body?:

unknown

messages:

Array<ResponseMessage>

warnings:

Promise<Warning[] | undefined>

responseMessages:

Promise<Array<ResponseMessage>>

steps:

Promise<Array<StepResult>>

StepResult

stepType:

"initial" | "continue" | "tool-result"

text:

string

reasoning:

string | undefined

sources:

Array<Source>

Source

sourceType:

'url'

id:

string

url:

string

title?:

string

providerMetadata?:

SharedV2ProviderMetadata

files:

Array<GeneratedFile>

GeneratedFile

base64:

string

uint8Array:

Uint8Array

mediaType:

string

toolCalls:

array

toolResults:

array

finishReason:

rawFinishReason:

string | undefined

usage:

LanguageModelUsage

inputTokens:

number | undefined

inputTokenDetails:

LanguageModelInputTokenDetails

noCacheTokens:

number | undefined

cacheReadTokens:

number | undefined

cacheWriteTokens:

number | undefined

outputTokens:

number | undefined

outputTokenDetails:

LanguageModelOutputTokenDetails

textTokens:

number | undefined

reasoningTokens:

number | undefined

totalTokens:

number | undefined

raw?:

object | undefined

request?:

RequestMetadata

messages?:

Array<ModelMessage>

body?:

unknown

response?:

ResponseMetadata

id:

string

modelId:

string

timestamp:

Date

headers?:

Record<string, string>

messages:

Array<ResponseMessage>

warnings:

Warning[] | undefined

isContinued:

boolean

providerMetadata?:

Record<string,JSONObject> | undefined

textStream:

AsyncIterableStream<string>

finalStep:

Promise<StepResult>

stream:

AsyncIterable<TextStreamPart<TOOLS>> & ReadableStream<TextStreamPart<TOOLS>>

TextStreamPart

type:

'text'

text:

string

TextStreamPart

type:

'reasoning'

text:

string

providerMetadata?:

ProviderMetadata

TextStreamPart

type:

'source'

sourceType:

'url'

id:

string

url:

string

title?:

string

providerMetadata?:

ProviderMetadata

TextStreamPart

type:

'file'

file:

GeneratedFile

base64:

string

uint8Array:

Uint8Array

mediaType:

string

TextStreamPart

type:

'custom'

kind:

string

providerMetadata?:

ProviderMetadata

TextStreamPart

type:

'tool-call'

toolCallId:

string

toolName:

string

input:

object based on tool parameters

TextStreamPart

type:

'tool-call-streaming-start'

toolCallId:

string

toolName:

string

TextStreamPart

type:

'tool-call-delta'

toolCallId:

string

toolName:

string

argsTextDelta:

string

TextStreamPart

type:

'tool-result'

toolCallId:

string

toolName:

string

input:

object based on tool parameters

output:

tool execution return type

TextStreamPart

type:

'start-step'

request:

LanguageModelRequestMetadata

messages:

Array<ModelMessage>

body?:

unknown

warnings:

Warning[]

TextStreamPart

type:

'finish-step'

response:

Omit<LanguageModelResponseMetadata, 'messages' | 'body'>

LanguageModelResponseMetadata

id:

string

modelId:

string

timestamp:

Date

headers:

Record<string, string>

usage:

LanguageModelUsage

inputTokens:

number | undefined

inputTokenDetails:

LanguageModelInputTokenDetails

noCacheTokens:

number | undefined

cacheReadTokens:

number | undefined

cacheWriteTokens:

number | undefined

outputTokens:

number | undefined

outputTokenDetails:

LanguageModelOutputTokenDetails

textTokens:

number | undefined

reasoningTokens:

number | undefined

totalTokens:

number | undefined

raw?:

object | undefined

performance:

StepResultPerformance

effectiveOutputTokensPerSecond:

number

outputTokensPerSecond:

number | undefined

inputTokensPerSecond:

number | undefined

effectiveTotalTokensPerSecond:

number

stepTimeMs:

number

responseTimeMs:

number

toolExecutionMs:

Readonly<Record<string, number>>

timeToFirstOutputMs:

number | undefined

timeBetweenOutputChunksMs:

OutputChunkTimingStats | undefined

finishReason:

rawFinishReason:

string | undefined

providerMetadata?:

ProviderMetadata | undefined

TextStreamPart

type:

'start'

TextStreamPart

type:

'finish'

finishReason:

rawFinishReason:

string | undefined

totalUsage:

LanguageModelUsage

inputTokens:

number | undefined

inputTokenDetails:

LanguageModelInputTokenDetails

noCacheTokens:

number | undefined

cacheReadTokens:

number | undefined

cacheWriteTokens:

number | undefined

outputTokens:

number | undefined

outputTokenDetails:

LanguageModelOutputTokenDetails

textTokens:

number | undefined

reasoningTokens:

number | undefined

totalTokens:

number | undefined

raw?:

object | undefined

TextStreamPart

type:

'reasoning-part-finish'

TextStreamPart

type:

'error'

error:

unknown

TextStreamPart

type:

'abort'

reason?:

unknown

fullStream:

AsyncIterable<TextStreamPart<TOOLS>> & ReadableStream<TextStreamPart<TOOLS>>

partialOutputStream:

AsyncIterableStream<PARTIAL_OUTPUT>

elementStream:

AsyncIterableStream<ELEMENT_OUTPUT>

output:

Promise<COMPLETE_OUTPUT>

consumeStream:

(options?: ConsumeStreamOptions) => Promise<void>

ConsumeStreamOptions

onError?:

(error: unknown) => void

toUIMessageStream:

(options?: UIMessageStreamOptions) => AsyncIterableStream<UIMessageChunk>

UIMessageStreamOptions

originalMessages?:

UIMessage[]

onEnd?:

(options: { messages: UIMessage[]; isContinuation: boolean; responseMessage: UIMessage; isAborted: boolean; }) => void

onFinish?:

(options: { messages: UIMessage[]; isContinuation: boolean; responseMessage: UIMessage; isAborted: boolean; }) => void

messageMetadata?:

(options: { part: TextStreamPart<TOOLS> & { type: "start" | "finish" | "start-step" | "finish-step"; }; }) => unknown

sendReasoning?:

boolean

sendSources?:

boolean

sendFinish?:

boolean

sendStart?:

boolean

onError?:

(error: unknown) => string

consumeSseStream?:

(stream: ReadableStream) => Promise<void>

pipeUIMessageStreamToResponse:

(response: ServerResponse, options?: ResponseInit & UIMessageStreamOptions) => void

ResponseInit & UIMessageStreamOptions

status?:

number

statusText?:

string

headers?:

HeadersInit

pipeTextStreamToResponse:

(response: ServerResponse, init?: ResponseInit) => void

ResponseInit

status?:

number

statusText?:

string

headers?:

Record<string, string>

toUIMessageStreamResponse:

(options?: ResponseInit & UIMessageStreamOptions) => Response

ResponseInit & UIMessageStreamOptions

status?:

number

statusText?:

string

headers?:

HeadersInit

toTextStreamResponse:

(init?: ResponseInit) => Response

ResponseInit

status?:

number

statusText?:

string

headers?:

Record<string, string>

Types

`ActiveTools`

type ActiveTools<TOOLS extends ToolSet> =
  | ReadonlyArray<keyof TOOLS & string>
  | undefined;

Limits a generation step to the listed tool names. undefined means no tool restriction is applied.

Examples

Learn to stream text generated by a language model in Next.js

Learn to stream chat completions generated by a language model in Next.js

Learn to stream text generated by a language model in Node.js

Learn to stream chat completions generated by a language model in Node.js

streamText()

Import

API Signature

Parameters

model:

instructions:

prompt:

messages:

role:

content:

role:

content:

type:

text:

type:

image:

mediaType?:

type:

data:

mediaType:

role:

content:

type:

text:

type:

text:

type:

data:

mediaType:

type:

data:

mediaType:

filename?:

type:

toolCallId:

toolName:

input:

role:

content:

type:

toolCallId:

toolName:

result:

isError?:

allowSystemInMessages?:

tools:

description?:

inputSchema:

execute?:

toolCallId:

messages:

abortSignal:

toolChoice?:

maxOutputTokens?:

temperature?:

topP?:

topK?:

presencePenalty?:

frequencyPenalty?:

stopSequences?:

seed?:

reasoning?:

maxRetries?:

abortSignal?:

timeout?:

headers?:

telemetry?:

isEnabled?:

recordInputs?:

recordOutputs?:

functionId?:

includeRuntimeContext?:

includeToolsContext?:

integrations?:

experimental_transform?:

transform:

stopStream:

tools:

includeRawChunks?:

providerOptions?:

`streamText()`