import type { LanguageModelV3ToolChoice } from '@ai-sdk/provider'; import type { ModelMessage, ProviderOptions, SystemModelMessage, } from '@ai-sdk/provider-utils'; import type { TimeoutConfiguration } from '../prompt/call-settings'; import type { ToolChoice } from '../types/language-model'; import type { LanguageModelUsage } from '../types/usage'; import type { Output } from './output'; import type { StepResult } from './step-result'; import type { StopCondition } from './stop-condition'; import type { TypedToolCall } from './tool-call'; import type { ToolSet } from './tool-set'; /** * Common model information used across callback events. */ export interface CallbackModelInfo { /** The provider identifier (e.g., 'openai', 'anthropic'). */ readonly provider: string; /** The specific model identifier (e.g., 'gpt-4o'). */ readonly modelId: string; } /** * Event passed to the `onStart` callback. * * Called when the generation operation begins, before any LLM calls. */ export interface OnStartEvent< TOOLS extends ToolSet = ToolSet, OUTPUT extends Output = Output, INCLUDE = { requestBody?: boolean; responseBody?: boolean }, > { /** The model being used for generation. */ readonly model: CallbackModelInfo; /** The system message(s) provided to the model. */ readonly system: | string | SystemModelMessage | Array | undefined; /** The prompt string or array of messages if using the prompt option. */ readonly prompt: string | Array | undefined; /** The messages array if using the messages option. */ readonly messages: Array | undefined; /** The tools available for this generation. */ readonly tools: TOOLS | undefined; /** The tool choice strategy for this generation. */ readonly toolChoice: ToolChoice> | undefined; /** Limits which tools are available for the model to call. */ readonly activeTools: Array | undefined; /** Maximum number of tokens to generate. */ readonly maxOutputTokens: number | undefined; /** Sampling temperature for generation. */ readonly temperature: number | undefined; /** Top-p (nucleus) sampling parameter. */ readonly topP: number | undefined; /** Top-k sampling parameter. */ readonly topK: number | undefined; /** Presence penalty for generation. */ readonly presencePenalty: number | undefined; /** Frequency penalty for generation. */ readonly frequencyPenalty: number | undefined; /** Sequences that will stop generation. */ readonly stopSequences: string[] | undefined; /** Random seed for reproducible generation. */ readonly seed: number | undefined; /** Maximum number of retries for failed requests. */ readonly maxRetries: number; /** * Timeout configuration for the generation. * Can be a number (milliseconds) or an object with totalMs, stepMs, chunkMs. */ readonly timeout: TimeoutConfiguration | undefined; /** Additional HTTP headers sent with the request. */ readonly headers: Record | undefined; /** Additional provider-specific options. */ readonly providerOptions: ProviderOptions | undefined; /** * Condition(s) for stopping the generation. * When the condition is an array, any of the conditions can be met to stop. */ readonly stopWhen: | StopCondition | Array> | undefined; /** The output specification for structured outputs, if configured. */ readonly output: OUTPUT | undefined; /** Abort signal for cancelling the operation. */ readonly abortSignal: AbortSignal | undefined; /** * Settings for controlling what data is included in step results. */ readonly include: INCLUDE | undefined; /** Identifier from telemetry settings for grouping related operations. */ readonly functionId: string | undefined; /** Additional metadata passed to the generation. */ readonly metadata: Record | undefined; /** * User-defined context object that flows through the entire generation lifecycle. * Can be accessed and modified in `prepareStep` and tool `execute` functions. */ readonly experimental_context: unknown; } /** * Event passed to the `onStepStart` callback. * * Called when a step (LLM call) begins, before the provider is called. * Each step represents a single LLM invocation. */ export interface OnStepStartEvent< TOOLS extends ToolSet = ToolSet, OUTPUT extends Output = Output, INCLUDE = { requestBody?: boolean; responseBody?: boolean }, > { /** Zero-based index of the current step. */ readonly stepNumber: number; /** The model being used for this step. */ readonly model: CallbackModelInfo; /** * The system message for this step. */ readonly system: | string | SystemModelMessage | Array | undefined; /** * The messages that will be sent to the model for this step. * Uses the user-facing `ModelMessage` format. * May be overridden by prepareStep. */ readonly messages: Array; /** The tools available for this generation. */ readonly tools: TOOLS | undefined; /** The tool choice configuration for this step. */ readonly toolChoice: LanguageModelV3ToolChoice | undefined; /** Limits which tools are available for this step. */ readonly activeTools: Array | undefined; /** Array of results from previous steps (empty for first step). */ readonly steps: ReadonlyArray>; /** Additional provider-specific options for this step. */ readonly providerOptions: ProviderOptions | undefined; /** * Timeout configuration for the generation. * Can be a number (milliseconds) or an object with totalMs, stepMs, chunkMs. */ readonly timeout: TimeoutConfiguration | undefined; /** Additional HTTP headers sent with the request. */ readonly headers: Record | undefined; /** * Condition(s) for stopping the generation. * When the condition is an array, any of the conditions can be met to stop. */ readonly stopWhen: | StopCondition | Array> | undefined; /** The output specification for structured outputs, if configured. */ readonly output: OUTPUT | undefined; /** Abort signal for cancelling the operation. */ readonly abortSignal: AbortSignal | undefined; /** * Settings for controlling what data is included in step results. */ readonly include: INCLUDE | undefined; /** Identifier from telemetry settings for grouping related operations. */ readonly functionId: string | undefined; /** Additional metadata from telemetry settings. */ readonly metadata: Record | undefined; /** * User-defined context object. May be updated from `prepareStep` between steps. */ readonly experimental_context: unknown; } /** * Event passed to the `onToolCallStart` callback. * * Called when a tool execution begins, before the tool's `execute` function is invoked. */ export interface OnToolCallStartEvent { /** Zero-based index of the current step where this tool call occurs. */ readonly stepNumber: number | undefined; /** The model being used for this step. */ readonly model: CallbackModelInfo | undefined; /** The full tool call object. */ readonly toolCall: TypedToolCall; /** The conversation messages available at tool execution time. */ readonly messages: Array; /** Signal for cancelling the operation. */ readonly abortSignal: AbortSignal | undefined; /** Identifier from telemetry settings for grouping related operations. */ readonly functionId: string | undefined; /** Additional metadata from telemetry settings. */ readonly metadata: Record | undefined; /** User-defined context object flowing through the generation. */ readonly experimental_context: unknown; } /** * Event passed to the `onToolCallFinish` callback. * * Called when a tool execution completes, either successfully or with an error. * Uses a discriminated union on the `success` field. */ export type OnToolCallFinishEvent = { /** Zero-based index of the current step where this tool call occurred. */ readonly stepNumber: number | undefined; /** The model being used for this step. */ readonly model: CallbackModelInfo | undefined; /** The full tool call object. */ readonly toolCall: TypedToolCall; /** The conversation messages available at tool execution time. */ readonly messages: Array; /** Signal for cancelling the operation. */ readonly abortSignal: AbortSignal | undefined; /** Execution time of the tool call in milliseconds. */ readonly durationMs: number; /** Identifier from telemetry settings for grouping related operations. */ readonly functionId: string | undefined; /** Additional metadata from telemetry settings. */ readonly metadata: Record | undefined; /** User-defined context object flowing through the generation. */ readonly experimental_context: unknown; } & ( | { /** Indicates the tool call succeeded. */ readonly success: true; /** The tool's return value. */ readonly output: unknown; readonly error?: never; } | { /** Indicates the tool call failed. */ readonly success: false; readonly output?: never; /** The error that occurred during tool execution. */ readonly error: unknown; } ); /** * Event passed to the `onStepFinish` callback. * * Called when a step (LLM call) completes. * This is simply the StepResult for that step. */ export type OnStepFinishEvent = StepResult; /** * Event passed to the `onFinish` callback. * * Called when the entire generation completes (all steps finished). * Includes the final step's result along with aggregated data from all steps. */ export type OnFinishEvent = StepResult & { /** Array containing results from all steps in the generation. */ readonly steps: StepResult[]; /** Aggregated token usage across all steps. */ readonly totalUsage: LanguageModelUsage; /** * The final state of the user-defined context object. * * Experimental (can break in patch releases). * * @default undefined */ experimental_context: unknown; /** Identifier from telemetry settings for grouping related operations. */ readonly functionId: string | undefined; /** Additional metadata from telemetry settings. */ readonly metadata: Record | undefined; };