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Prompt

Defines prompts sent to AI language models.

A prompt is an ordered list of messages. Messages can use roles such as system, user, assistant, and tool, and their content can be split into typed parts such as text, files, reasoning, tool calls, tool results, and approval messages. This module helps build prompts, combine them, and convert raw input or response parts into the shared prompt shape.

96 exports Added in v4.0.0 Source

Combinators

appendSystem

Added in v4.0.0 Source

Creates a new prompt with a leading system message. If the prompt already has a system message, the new message uses the provided content appended to the first existing system message's content; the original messages remain after it.

Signature

declare const appendSystem: {
(content: string): (self: Prompt) => Prompt;
(self: Prompt, content: string): Prompt;
}

Example

(Appending system instructions)

import { Prompt } from "effect/unstable/ai"
const systemPrompt = Prompt.make([{
role: "system",
content: "You are an expert in programming."
}])
const userPrompt = Prompt.make("Hello, world!")
const prompt = Prompt.concat(systemPrompt, userPrompt)
const replaced = Prompt.appendSystem(
prompt,
" You are a helpful assistant."
)
// result content: "You are an expert in programming. You are a helpful assistant."
replaced.content[0].content // => "You are an expert in programming. You are a helpful assistant."

concat

Added in v4.0.0 Source

Concatenates a prompt with additional raw input by concatenating messages.

Details

The returned prompt contains all messages from the original prompt followed by the provided raw input, preserving message order.

Signature

declare const concat: {
(input: RawInput): (self: Prompt) => Prompt;
(self: Prompt, input: RawInput): Prompt;
}

Example

(Concatenating prompts)

import { Prompt } from "effect/unstable/ai"
const systemPrompt = Prompt.make([{
role: "system",
content: "You are a helpful assistant."
}])
const merged = Prompt.concat(systemPrompt, "Hello, world!")
merged.content.map((message) => message.role) // => ["system", "user"]

Creates a new prompt with a leading system message. If the prompt already has a system message, the new message uses the provided content prepended to the first existing system message's content; the original messages remain after it.

Signature

declare const prependSystem: {
(content: string): (self: Prompt) => Prompt;
(self: Prompt, content: string): Prompt;
}

Example

(Prepending system instructions)

import { Prompt } from "effect/unstable/ai"
const systemPrompt = Prompt.make([{
role: "system",
content: "You are an expert in programming."
}])
const userPrompt = Prompt.make("Hello, world!")
const prompt = Prompt.concat(systemPrompt, userPrompt)
const replaced = Prompt.prependSystem(
prompt,
"You are a helpful assistant. "
)
// result content: "You are a helpful assistant. You are an expert in programming."
replaced.content[0].content // => "You are a helpful assistant. You are an expert in programming."

setSystem

Added in v4.0.0 Source

Creates a new prompt from the specified prompt with the system message set to the specified text content.

Gotchas

This method removes and replaces any previous system message from the prompt.

Signature

declare const setSystem: {
(content: string): (self: Prompt) => Prompt;
(self: Prompt, content: string): Prompt;
}

Example

(Replacing system instructions)

import { Prompt } from "effect/unstable/ai"
const systemPrompt = Prompt.make([{
role: "system",
content: "You are a helpful assistant."
}])
const userPrompt = Prompt.make("Hello, world!")
const prompt = Prompt.concat(systemPrompt, userPrompt)
const replaced = Prompt.setSystem(
prompt,
"You are an expert in programming"
)
replaced.content[0].content // => "You are an expert in programming"

Constructors

Constructs a new assistant message.

When to use

Use to add assistant-role prompt history or model responses.

Details

This is the role-specific wrapper around makeMessage("assistant", params).

Signature

declare function assistantMessage(params: MessageConstructorParams<AssistantMessage>): AssistantMessage

empty

Added in v4.0.0 Source

An empty prompt with no messages.

Signature

declare const empty: Prompt

Example

(Creating an empty prompt)

import { Prompt } from "effect/unstable/ai"
const emptyPrompt = Prompt.empty
emptyPrompt.content // => []

filePart

Added in v4.0.0 Source

Constructs a FilePart for prompt file attachments.

When to use

Use to create the file-attachment part of a prompt from typed file part parameters.

See

  • makePart for the generic part constructor

Signature

declare function filePart(params: PartConstructorParams<FilePart>): FilePart

fromMessages

Added in v4.0.0 Source

Creates a Prompt from an array of messages.

Signature

declare function fromMessages(messages: readonly Array<Message>): Prompt

Example

(Creating prompts from messages)

import { Prompt } from "effect/unstable/ai"
const messages: ReadonlyArray<Prompt.Message> = [
Prompt.makeMessage("system", {
content: "You are a coding assistant."
}),
Prompt.makeMessage("user", {
content: [Prompt.makePart("text", { text: "Help me with TypeScript" })]
})
]
const prompt = Prompt.fromMessages(messages)
prompt.content.length // => 2

Creates a Prompt from response parts by folding completed text and reasoning streams into assistant parts, preserving provider metadata as prompt options, placing tool calls and approval requests in an assistant message, and placing non-preliminary tool results in a tool message using their encoded results.

Signature

declare function fromResponseParts(parts: readonly Array<AnyPart>): Prompt

Example

(Creating prompts from response parts)

import { Prompt, Response } from "effect/unstable/ai"
const responseParts: ReadonlyArray<Response.AnyPart> = [
Response.makePart("text", {
text: "Hello there!"
}),
Response.makePart("tool-call", {
id: "call_1",
name: "get_time",
params: {},
providerExecuted: false
}),
Response.makePart("tool-result", {
id: "call_1",
name: "get_time",
isFailure: false,
result: "10:30 AM",
encodedResult: "10:30 AM",
providerExecuted: false,
preliminary: false
})
]
const prompt = Prompt.fromResponseParts(responseParts)
// Creates an assistant message with the response content
prompt.content.map((message) => message.role) // => ["assistant", "tool"]

make

Added in v4.0.0 Source

Creates a Prompt from an input.

Details

This is the primary constructor for creating prompts, supporting multiple input formats for convenience and flexibility.

Signature

declare function make(input: RawInput): Prompt

Example

(Creating prompts from inputs)

import { Prompt } from "effect/unstable/ai"
// From string - creates a user message
const textPrompt = Prompt.make("Hello, how are you?")
// From messages array
const structuredPrompt = Prompt.make([
{ role: "system", content: "You are a helpful assistant." },
{ role: "user", content: [{ type: "text", text: "Hi!" }] }
])
const copiedPrompt = Prompt.make(Prompt.empty)
const result = [textPrompt.content[0].role, structuredPrompt.content.length, copiedPrompt.content.length] // => ["user", 2, 0]

makeMessage

Added in v4.0.0 Source

Creates a new message with the specified role.

Signature

declare function makeMessage<Role extends "tool" | "user" | "assistant" | "system">(role: Role, params: Omit<Extract<SystemMessage, {
role: Role;
}> | Extract<UserMessage, {
role: Role;
}> | Extract<AssistantMessage, {
role: Role;
}> | Extract<ToolMessage, {
role: Role;
}>, "role" | "options" | "~effect/ai/Prompt/Message"> & {
readonly options?: Extract<SystemMessage, {
role: Role;
}> | Extract<UserMessage, {
role: Role;
}> | Extract<AssistantMessage, {
role: Role;
}> | Extract<ToolMessage, {
role: Role;
}>["options"];
}): Extract<SystemMessage, {
role: Role;
}> | Extract<UserMessage, {
role: Role;
}> | Extract<AssistantMessage, {
role: Role;
}> | Extract<ToolMessage, {
role: Role;
}>

Example

(Creating messages)

import { Prompt } from "effect/unstable/ai"
const textPart = Prompt.makePart("text", {
text: "Hello, world!"
})
const userMessage = Prompt.makeMessage("user", {
content: [textPart]
})
const result = [userMessage.role, userMessage.content.length] // => ["user", 1]

makePart

Added in v4.0.0 Source

Creates a new content part of the specified type.

Signature

declare function makePart<Type extends "tool-approval-request" | "file" | "text" | "reasoning" | "tool-call" | "tool-result" | "tool-approval-response">(type: Type, params: Omit<Extract<TextPart, {
type: Type;
}> | Extract<ReasoningPart, {
type: Type;
}> | Extract<FilePart, {
type: Type;
}> | Extract<ToolCallPart, {
type: Type;
}> | Extract<ToolResultPart, {
type: Type;
}> | Extract<ToolApprovalResponsePart, {
type: Type;
}> | Extract<ToolApprovalRequestPart, {
type: Type;
}>, "type" | "~effect/ai/Prompt/Part" | "options"> & {
readonly options?: Extract<TextPart, {
type: Type;
}> | Extract<ReasoningPart, {
type: Type;
}> | Extract<FilePart, {
type: Type;
}> | Extract<ToolCallPart, {
type: Type;
}> | Extract<ToolResultPart, {
type: Type;
}> | Extract<ToolApprovalResponsePart, {
type: Type;
}> | Extract<ToolApprovalRequestPart, {
type: Type;
}>["options"];
}): Extract<TextPart, {
type: Type;
}> | Extract<ReasoningPart, {
type: Type;
}> | Extract<FilePart, {
type: Type;
}> | Extract<ToolCallPart, {
type: Type;
}> | Extract<ToolResultPart, {
type: Type;
}> | Extract<ToolApprovalResponsePart, {
type: Type;
}> | Extract<ToolApprovalRequestPart, {
type: Type;
}>

Example

(Creating content parts)

import { Prompt } from "effect/unstable/ai"
const textPart = Prompt.makePart("text", {
text: "Hello, world!"
})
const filePart = Prompt.makePart("file", {
mediaType: "image/png",
fileName: "screenshot.png",
data: new Uint8Array([1, 2, 3])
})
const result = [textPart.type, filePart.type] // => ["text", "file"]

Constructs a new reasoning part.

Signature

declare function reasoningPart(params: PartConstructorParams<ReasoningPart>): ReasoningPart

Constructs a new system message.

Signature

declare function systemMessage(params: MessageConstructorParams<SystemMessage>): SystemMessage

textPart

Added in v4.0.0 Source

Constructs a new text part.

Signature

declare function textPart(params: PartConstructorParams<TextPart>): TextPart

Constructs a new tool approval request part.

Signature

declare function toolApprovalRequestPart(params: PartConstructorParams<ToolApprovalRequestPart>): ToolApprovalRequestPart

Constructs a new tool approval response part.

Signature

declare function toolApprovalResponsePart(params: PartConstructorParams<ToolApprovalResponsePart>): ToolApprovalResponsePart

toolCallPart

Added in v4.0.0 Source

Constructs a new tool call part.

Signature

declare function toolCallPart(params: PartConstructorParams<ToolCallPart>): ToolCallPart

toolMessage

Added in v4.0.0 Source

Constructs a new tool message.

Signature

declare function toolMessage(params: MessageConstructorParams<ToolMessage>): ToolMessage

Constructs a new tool result part.

Signature

declare function toolResultPart(params: PartConstructorParams<ToolResultPart>): ToolResultPart

userMessage

Added in v4.0.0 Source

Constructs a new user message.

Signature

declare function userMessage(params: MessageConstructorParams<UserMessage>): UserMessage

Guards

isMessage

Added in v4.0.0 Source

Type guard to check if a value is a Message.

Signature

declare function isMessage(u: unknown): u is Message

isPart

Added in v4.0.0 Source

Type guard to check if a value is a Part.

Signature

declare function isPart(u: unknown): u is Part

isPrompt

Added in v4.0.0 Source

Type guard to check if a value is a Prompt.

Signature

declare function isPrompt(u: unknown): u is Prompt

Models

AssistantMessage interface

Added in v4.0.0 Source

Message representing large language model assistant responses.

Signature

interface AssistantMessage extends BaseMessage<"assistant", AssistantMessageOptions> {
readonly content: readonly Array<AssistantMessagePart>;
}

Example

(Creating assistant messages)

import { Prompt } from "effect/unstable/ai"
const assistantMessage: Prompt.AssistantMessage = Prompt.makeMessage(
"assistant",
{
content: [
Prompt.makePart("text", {
text:
"I can check the current weather for San Francisco."
}),
Prompt.makePart("tool-call", {
id: "call_123",
name: "get_weather",
params: { city: "San Francisco" },
providerExecuted: false
}),
Prompt.makePart("tool-result", {
id: "call_123",
name: "get_weather",
isFailure: false,
result: {
temperature: 72,
condition: "sunny"
},
providerExecuted: true
}),
Prompt.makePart("text", {
text: "The weather in San Francisco is currently 72°F and sunny."
})
]
}
)
assistantMessage.content.map((part) => part.type) // => ["text", "tool-call", "tool-result", "text"]

AssistantMessageEncoded interface

Added in v4.0.0 Source

Encoded representation of assistant messages for serialization.

Signature

interface AssistantMessageEncoded extends BaseMessageEncoded<"assistant", AssistantMessageOptions> {
readonly content: string | readonly Array<AssistantMessagePartEncoded>;
}

AssistantMessagePart type

Added in v4.0.0 Source

Union type of content parts allowed in assistant messages.

Signature

type AssistantMessagePart = TextPart | FilePart | ReasoningPart | ToolCallPart | ToolResultPart | ToolApprovalRequestPart

Union type of encoded content parts for assistant messages.

Signature

type AssistantMessagePartEncoded = TextPartEncoded | FilePartEncoded | ReasoningPartEncoded | ToolCallPartEncoded | ToolResultPartEncoded | ToolApprovalRequestPartEncoded

BaseMessage interface

Added in v4.0.0 Source

Base interface for all message types.

Details

It provides the common structure shared by all messages, including the role and provider options.

Signature

interface BaseMessage<Role extends string, Options extends ProviderOptions> {
readonly "~effect/ai/Prompt/Message": "~effect/ai/Prompt/Message";
readonly options: Options;
readonly role: Role;
}

BaseMessageEncoded interface

Added in v4.0.0 Source

Base interface for encoded message types.

Signature

interface BaseMessageEncoded<Role extends string, Options extends ProviderOptions> {
readonly options?: Options;
readonly role: Role;
}

BasePart interface

Added in v4.0.0 Source

Base interface for all content parts.

Details

It provides the common structure shared by all content parts, including the part type and provider options.

Signature

interface BasePart<Type extends string, Options extends ProviderOptions> {
readonly "~effect/ai/Prompt/Part": "~effect/ai/Prompt/Part";
readonly options: Options;
readonly type: Type;
}

BasePartEncoded interface

Added in v4.0.0 Source

Base interface for encoded content parts.

Signature

interface BasePartEncoded<Type extends string, Options extends ProviderOptions> {
readonly options?: Options;
readonly type: Type;
}

FilePart interface

Added in v4.0.0 Source

Content part representing a file attachment.

Details

Files can be provided as base64 data strings, byte arrays, or URLs, and can represent images, documents, or other binary data.

Signature

interface FilePart extends BasePart<"file", FilePartOptions> {
readonly data: string | Uint8Array<ArrayBufferLike> | URL;
readonly fileName?: string;
readonly mediaType: string;
}

Example

(Creating file parts)

import { Prompt } from "effect/unstable/ai"
const imagePart: Prompt.FilePart = Prompt.makePart("file", {
mediaType: "image/jpeg",
fileName: "photo.jpg",
data: "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQ..."
})
const documentPart: Prompt.FilePart = Prompt.makePart("file", {
mediaType: "application/pdf",
fileName: "report.pdf",
data: new Uint8Array([1, 2, 3])
})
const result = [imagePart.mediaType, documentPart.fileName] // => ["image/jpeg", "report.pdf"]

FilePartEncoded interface

Added in v4.0.0 Source

Encoded representation of file parts for serialization.

Signature

interface FilePartEncoded extends BasePartEncoded<"file", FilePartOptions> {
readonly data: string | Uint8Array<ArrayBufferLike> | URL;
readonly fileName?: string;
readonly mediaType: string;
}

Message type

Added in v4.0.0 Source

A type representing all possible message types in a conversation.

Signature

type Message = SystemMessage | UserMessage | AssistantMessage | ToolMessage

MessageEncoded type

Added in v4.0.0 Source

A type representing all possible encoded message types for serialization.

Signature

type MessageEncoded = SystemMessageEncoded | UserMessageEncoded | AssistantMessageEncoded | ToolMessageEncoded

Part type

Added in v4.0.0 Source

Union type representing all possible content parts within messages.

Details

Parts are the building blocks of message content, supporting text, files, reasoning, tool calls, tool results, tool approval responses, and tool approval requests.

Signature

type Part = TextPart | ReasoningPart | FilePart | ToolCallPart | ToolResultPart | ToolApprovalResponsePart | ToolApprovalRequestPart

PartEncoded type

Added in v4.0.0 Source

Encoded representation of a Part.

Signature

type PartEncoded = TextPartEncoded | ReasoningPartEncoded | FilePartEncoded | ToolCallPartEncoded | ToolResultPartEncoded | ToolApprovalResponsePartEncoded | ToolApprovalRequestPartEncoded

Prompt interface

Added in v4.0.0 Source

A Prompt contains a sequence of messages that form the context of a conversation with a large language model.

Signature

interface Prompt extends Pipeable {
readonly "~effect/unstable/ai/Prompt": "~effect/unstable/ai/Prompt";
readonly content: readonly Array<Message>;
}

PromptEncoded interface

Added in v4.0.0 Source

Encoded representation of prompts for serialization.

Signature

interface PromptEncoded {
readonly content: readonly Array<MessageEncoded>;
}

RawInput type

Added in v4.0.0 Source

Raw input accepted by make: a string, an iterable of encoded messages, or an existing Prompt.

Signature

type RawInput = string | Iterable<MessageEncoded> | Prompt

Example

(Accepting raw prompt input)

import { Prompt } from "effect/unstable/ai"
// String input - creates a user message
const stringInput: Prompt.RawInput = "Hello, world!"
// Message array input
const messagesInput: Prompt.RawInput = [
{ role: "system", content: "You are helpful." },
{ role: "user", content: [{ type: "text", text: "Hi!" }] }
]
const promptInput: Prompt.RawInput = Prompt.empty
const result = [typeof stringInput, Array.isArray(messagesInput), promptInput.content.length] // => ["string", true, 0]

ReasoningPart interface

Added in v4.0.0 Source

Content part carrying reasoning text in an assistant message, such as a provider-supplied reasoning summary or explanation.

Signature

interface ReasoningPart extends BasePart<"reasoning", ReasoningPartOptions> {
readonly text: string;
}

Example

(Creating reasoning parts)

import { Prompt } from "effect/unstable/ai"
const reasoningPart: Prompt.ReasoningPart = Prompt.makePart("reasoning", {
text:
"Summary: the response compares the requested options by price and availability."
})
reasoningPart.type // => "reasoning"

ReasoningPartEncoded interface

Added in v4.0.0 Source

Encoded representation of reasoning parts for serialization.

Signature

interface ReasoningPartEncoded extends BasePartEncoded<"reasoning", ReasoningPartOptions> {
readonly text: string;
}

SystemMessage interface

Added in v4.0.0 Source

Message representing system instructions or context.

Signature

interface SystemMessage extends BaseMessage<"system", SystemMessageOptions> {
readonly content: string;
}

Example

(Creating system messages)

import { Prompt } from "effect/unstable/ai"
const systemMessage: Prompt.SystemMessage = Prompt.makeMessage("system", {
content: "You are a helpful assistant specialized in mathematics. " +
"Always show your work step by step."
})
systemMessage.role // => "system"

SystemMessageEncoded interface

Added in v4.0.0 Source

Encoded representation of system messages for serialization.

Signature

interface SystemMessageEncoded extends BaseMessageEncoded<"system", SystemMessageOptions> {
readonly content: string;
}

TextPart interface

Added in v4.0.0 Source

Content part representing plain text.

Details

Text parts are the basic content type used for textual information in messages.

Signature

interface TextPart extends BasePart<"text", TextPartOptions> {
readonly text: string;
}

Example

(Creating text parts)

import { Prompt } from "effect/unstable/ai"
const textPart: Prompt.TextPart = Prompt.makePart("text", {
text: "Hello, how can I help you today?"
})
textPart.text // => "Hello, how can I help you today?"

TextPartEncoded interface

Added in v4.0.0 Source

Encoded representation of text parts for serialization.

Signature

interface TextPartEncoded extends BasePartEncoded<"text", TextPartOptions> {
readonly text: string;
}

ToolApprovalRequestPart interface

Added in v4.0.0 Source

Content part representing a tool approval request from the framework.

Details

Tool approval request parts are stored in assistant messages when a tool requires user approval before execution. The user responds with a ToolApprovalResponsePart in a tool message.

Signature

interface ToolApprovalRequestPart extends BasePart<"tool-approval-request", ToolApprovalRequestPartOptions> {
readonly approvalId: string;
readonly toolCallId: string;
}

Example

(Creating tool approval requests)

import { Prompt } from "effect/unstable/ai"
const approvalRequest: Prompt.ToolApprovalRequestPart = Prompt.makePart(
"tool-approval-request",
{
approvalId: "approval_123",
toolCallId: "call_456"
}
)
const result = [approvalRequest.approvalId, approvalRequest.toolCallId] // => ["approval_123", "call_456"]

Encoded representation of tool approval request parts for serialization.

Signature

interface ToolApprovalRequestPartEncoded extends BasePartEncoded<"tool-approval-request", ToolApprovalRequestPartOptions> {
readonly approvalId: string;
readonly toolCallId: string;
}

ToolApprovalResponsePart interface

Added in v4.0.0 Source

Content part representing a user's response to a tool approval request.

When to use

Use when tool messages must approve or deny tool execution for tools with the needsApproval property set.

Signature

interface ToolApprovalResponsePart extends BasePart<"tool-approval-response", ToolApprovalResponsePartOptions> {
readonly approvalId: string;
readonly approved: boolean;
readonly reason?: string;
}

Example

(Creating tool approval responses)

import { Prompt } from "effect/unstable/ai"
const approvalResponse: Prompt.ToolApprovalResponsePart = Prompt.makePart(
"tool-approval-response",
{
approvalId: "approval_123",
approved: true
}
)
const denialResponse: Prompt.ToolApprovalResponsePart = Prompt.makePart(
"tool-approval-response",
{
approvalId: "approval_456",
approved: false,
reason: "Operation not allowed"
}
)
const result = [approvalResponse.approved, denialResponse.approved] // => [true, false]

Encoded representation of tool approval response parts for serialization.

Signature

interface ToolApprovalResponsePartEncoded extends BasePartEncoded<"tool-approval-response", ToolApprovalResponsePartOptions> {
readonly approvalId: string;
readonly approved: boolean;
readonly reason?: string;
}

ToolCallPart interface

Added in v4.0.0 Source

Content part representing a tool call request.

Signature

interface ToolCallPart extends BasePart<"tool-call", ToolCallPartOptions> {
readonly id: string;
readonly name: string;
readonly params: unknown;
readonly providerExecuted: boolean;
}

Example

(Creating tool call parts)

import { Prompt } from "effect/unstable/ai"
const toolCallPart: Prompt.ToolCallPart = Prompt.makePart("tool-call", {
id: "call_123",
name: "get_weather",
params: { city: "San Francisco", units: "celsius" },
providerExecuted: false
})
toolCallPart.name // => "get_weather"

ToolCallPartEncoded interface

Added in v4.0.0 Source

Encoded representation of tool call parts for serialization.

Signature

interface ToolCallPartEncoded extends BasePartEncoded<"tool-call", ToolCallPartOptions> {
readonly id: string;
readonly name: string;
readonly params: unknown;
readonly providerExecuted?: boolean;
}

ToolMessage interface

Added in v4.0.0 Source

Message carrying tool-side content, including tool execution results and responses to tool approval requests.

Signature

interface ToolMessage extends BaseMessage<"tool", ToolMessageOptions> {
readonly content: readonly Array<ToolMessagePart>;
}

Example

(Creating tool messages)

import { Prompt } from "effect/unstable/ai"
const toolMessage: Prompt.ToolMessage = Prompt.makeMessage("tool", {
content: [
Prompt.makePart("tool-result", {
id: "call_123",
name: "search_web",
isFailure: false,
result: {
query: "TypeScript best practices",
results: [
{ title: "TypeScript Handbook", url: "https://..." },
{ title: "Effective TypeScript", url: "https://..." }
]
},
providerExecuted: false
})
]
})
const result = [toolMessage.role, toolMessage.content[0].type] // => ["tool", "tool-result"]

ToolMessageEncoded interface

Added in v4.0.0 Source

Encoded representation of tool messages for serialization.

Signature

interface ToolMessageEncoded extends BaseMessageEncoded<"tool", ToolMessageOptions> {
readonly content: readonly Array<ToolMessagePartEncoded>;
}

ToolMessagePart type

Added in v4.0.0 Source

Union type of content parts allowed in tool messages.

Signature

type ToolMessagePart = ToolResultPart | ToolApprovalResponsePart

Union type of encoded content parts for tool messages.

Signature

type ToolMessagePartEncoded = ToolResultPartEncoded | ToolApprovalResponsePartEncoded

ToolResultPart interface

Added in v4.0.0 Source

Content part representing the result of a tool call.

Signature

interface ToolResultPart extends BasePart<"tool-result", ToolResultPartOptions> {
readonly id: string;
readonly isFailure: boolean;
readonly name: string;
readonly providerExecuted: boolean;
readonly result: unknown;
}

Example

(Creating tool result parts)

import { Prompt } from "effect/unstable/ai"
const toolResultPart: Prompt.ToolResultPart = Prompt.makePart("tool-result", {
id: "call_123",
name: "get_weather",
isFailure: false,
result: {
temperature: 22,
condition: "sunny",
humidity: 65
},
providerExecuted: false
})
const result = [toolResultPart.name, toolResultPart.isFailure] // => ["get_weather", false]

ToolResultPartEncoded interface

Added in v4.0.0 Source

Encoded representation of tool result parts for serialization.

Signature

interface ToolResultPartEncoded extends BasePartEncoded<"tool-result", ToolResultPartOptions> {
readonly id: string;
readonly isFailure: boolean;
readonly name: string;
readonly providerExecuted?: boolean;
readonly result: unknown;
}

UserMessage interface

Added in v4.0.0 Source

Message representing user input or questions.

Signature

interface UserMessage extends BaseMessage<"user", UserMessageOptions> {
readonly content: readonly Array<UserMessagePart>;
}

Example

(Creating user messages)

import { Prompt } from "effect/unstable/ai"
const textUserMessage: Prompt.UserMessage = Prompt.makeMessage("user", {
content: [
Prompt.makePart("text", {
text: "Can you analyze this image for me?"
})
]
})
const multimodalUserMessage: Prompt.UserMessage = Prompt.makeMessage("user", {
content: [
Prompt.makePart("text", {
text: "What do you see in this image?"
}),
Prompt.makePart("file", {
mediaType: "image/jpeg",
fileName: "vacation.jpg",
data: "data:image/jpeg;base64,..."
})
]
})
const result = [textUserMessage.content.length, multimodalUserMessage.content.length] // => [1, 2]

UserMessageEncoded interface

Added in v4.0.0 Source

Encoded representation of user messages for serialization.

Signature

interface UserMessageEncoded extends BaseMessageEncoded<"user", UserMessageOptions> {
readonly content: string | readonly Array<UserMessagePartEncoded>;
}

UserMessagePart type

Added in v4.0.0 Source

Union type of content parts allowed in user messages.

Signature

type UserMessagePart = TextPart | FilePart

Union type of encoded content parts for user messages.

Signature

type UserMessagePartEncoded = TextPartEncoded | FilePartEncoded

Options

AssistantMessageOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a AssistantMessage through module augmentation.

Signature

interface AssistantMessageOptions extends ProviderOptions {
[key: string]: Json;
}

FilePartOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a FilePart through module augmentation.

Signature

interface FilePartOptions extends ProviderOptions {
[key: string]: Json;
}

Schema for provider-specific options that can be attached to content parts and messages.

Details

Provider-specific options are keyed by provider-specific names, and each value is JSON or null.

Signature

declare const ProviderOptions: Schema.$Record<Schema.String, Schema.NullOr<Schema.Codec<Schema.Json>>>

ProviderOptions type

Added in v4.0.0 Source

Type of provider-specific options that can be attached to prompt messages and content parts.

Signature

type ProviderOptions = typeof ProviderOptions.Type

ReasoningPartOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a ReasoningPart through module augmentation.

Signature

interface ReasoningPartOptions extends ProviderOptions {
[key: string]: Json;
}

SystemMessageOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a SystemMessage through module augmentation.

Signature

interface SystemMessageOptions extends ProviderOptions {
[key: string]: Json;
}

TextPartOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a TextPart through module augmentation.

Signature

interface TextPartOptions extends ProviderOptions {
[key: string]: Json;
}

Represents provider-specific options that can be associated with a ToolApprovalRequestPart through module augmentation.

Signature

interface ToolApprovalRequestPartOptions extends ProviderOptions {
[key: string]: Json;
}

Represents provider-specific options that can be associated with a ToolApprovalResponsePart through module augmentation.

Signature

interface ToolApprovalResponsePartOptions extends ProviderOptions {
[key: string]: Json;
}

ToolCallPartOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a ToolCallPart through module augmentation.

Signature

interface ToolCallPartOptions extends ProviderOptions {
[key: string]: Json;
}

ToolMessageOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a ToolMessage through module augmentation.

Signature

interface ToolMessageOptions extends ProviderOptions {
[key: string]: Json;
}

ToolResultPartOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a ToolResultPart through module augmentation.

Signature

interface ToolResultPartOptions extends ProviderOptions {
[key: string]: Json;
}

UserMessageOptions interface

Added in v4.0.0 Source

Represents provider-specific options that can be associated with a UserMessage through module augmentation.

Signature

interface UserMessageOptions extends ProviderOptions {
[key: string]: Json;
}

Schemas

Schema for validation and encoding of assistant messages.

Details

Assistant content can be a string decoded through ContentFromString or an array of text, file, reasoning, tool-call, tool-result, and tool-approval-request parts.

Signature

declare const AssistantMessage: Struct<{
readonly "~effect/ai/Prompt/Message": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Message">>;
readonly content: Union<readonly [decodeTo<NonEmptyArray<toType<Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly text: String;
readonly type: Literal<"text">;
}>>>, String, never, never>, $Array<Union<readonly [Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly text: String;
readonly type: Literal<"text">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly data: Union<readonly [..., ..., ...]>;
readonly fileName: optional<String>;
readonly mediaType: String;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly type: Literal<"file">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly text: String;
readonly type: Literal<"reasoning">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly id: String;
readonly name: String;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly params: Unknown;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly type: Literal<"tool-call">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly id: String;
readonly isFailure: Boolean;
readonly name: String;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly result: Unknown;
readonly type: Literal<"tool-result">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly approvalId: String;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly toolCallId: String;
readonly type: Literal<"tool-approval-request">;
}>]>>]>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly role: Literal<"assistant">;
}>

Schema for validation and encoding of assistant message content parts.

Signature

declare const AssistantMessagePart: Union<readonly [Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly text: String;
readonly type: Literal<"text">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly data: Union<readonly [String, Uint8Array, URL]>;
readonly fileName: optional<String>;
readonly mediaType: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly type: Literal<"file">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly text: String;
readonly type: Literal<"reasoning">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly params: Unknown;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly type: Literal<"tool-call">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly isFailure: Boolean;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly result: Unknown;
readonly type: Literal<"tool-result">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly approvalId: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly toolCallId: String;
readonly type: Literal<"tool-approval-request">;
}>]>

Schema that decodes a string into content containing a single TextPart and, when encoding, emits the text value of the first part.

Signature

declare const ContentFromString: Schema.decodeTo<Schema.NonEmptyArray<Schema.toType<Schema.Struct<{
readonly "~effect/ai/Prompt/Part": Schema.withDecodingDefaultKey<Schema.Literal<"~effect/ai/Prompt/Part">>;
readonly options: Schema.withDecodingDefault<Schema.$Record<Schema.String, Schema.NullOr<Schema.Codec<Schema.Json>>>>;
readonly text: Schema.String;
readonly type: Schema.Literal<"text">;
}>>>, Schema.String>

FilePart

Added in v4.0.0 Source

Schema for validation and encoding of file parts.

Signature

declare const FilePart: Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly data: Union<readonly [String, Uint8Array, URL]>;
readonly fileName: optional<String>;
readonly mediaType: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly type: Literal<"file">;
}>

Message

Added in v4.0.0 Source

Schema for validation and encoding of messages.

Signature

declare const Message: Codec<Message, MessageEncoded, never, never>

Part

Added in v4.0.0 Source

Schema for validation and encoding of content parts.

Signature

declare const Part: Union<readonly [Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly text: String;
readonly type: Literal<"text">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly text: String;
readonly type: Literal<"reasoning">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly data: Union<readonly [String, Uint8Array, URL]>;
readonly fileName: optional<String>;
readonly mediaType: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly type: Literal<"file">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly params: Unknown;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly type: Literal<"tool-call">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly isFailure: Boolean;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly result: Unknown;
readonly type: Literal<"tool-result">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly approvalId: String;
readonly approved: Boolean;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly reason: optional<String>;
readonly type: Literal<"tool-approval-response">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly approvalId: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly toolCallId: String;
readonly type: Literal<"tool-approval-request">;
}>]>

Prompt

Added in v4.0.0 Source

Schema for AI prompt instances.

Signature

declare const Prompt: Codec<Prompt, PromptEncoded, never, never>

Schema for validation and encoding of reasoning parts.

Signature

declare const ReasoningPart: Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly text: String;
readonly type: Literal<"reasoning">;
}>

Schema for validation and encoding of system messages.

Signature

declare const SystemMessage: Struct<{
readonly "~effect/ai/Prompt/Message": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Message">>;
readonly content: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly role: Literal<"system">;
}>

TextPart

Added in v4.0.0 Source

Schema for validation and encoding of text parts.

Signature

declare const TextPart: Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly text: String;
readonly type: Literal<"text">;
}>

Schema for validation and encoding of tool approval request parts.

Signature

declare const ToolApprovalRequestPart: Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly approvalId: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly toolCallId: String;
readonly type: Literal<"tool-approval-request">;
}>

Schema for validation and encoding of tool approval response parts.

Signature

declare const ToolApprovalResponsePart: Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly approvalId: String;
readonly approved: Boolean;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly reason: optional<String>;
readonly type: Literal<"tool-approval-response">;
}>

ToolCallPart

Added in v4.0.0 Source

Schema for validation and encoding of tool call parts.

Signature

declare const ToolCallPart: Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly params: Unknown;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly type: Literal<"tool-call">;
}>

ToolMessage

Added in v4.0.0 Source

Schema for validation and encoding of tool messages.

Signature

declare const ToolMessage: Struct<{
readonly "~effect/ai/Prompt/Message": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Message">>;
readonly content: $Array<Union<readonly [Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly isFailure: Boolean;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<..., ..., ..., ...>>>>;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly result: Unknown;
readonly type: Literal<"tool-result">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly approvalId: String;
readonly approved: Boolean;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<..., ..., ..., ...>>>>;
readonly reason: optional<String>;
readonly type: Literal<"tool-approval-response">;
}>]>>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly role: Literal<"tool">;
}>

Schema for validation and encoding of tool message content parts.

Signature

declare const ToolMessagePart: Union<readonly [Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly isFailure: Boolean;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly result: Unknown;
readonly type: Literal<"tool-result">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly approvalId: String;
readonly approved: Boolean;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly reason: optional<String>;
readonly type: Literal<"tool-approval-response">;
}>]>

Schema for validation and encoding of tool result parts.

Signature

declare const ToolResultPart: Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly id: String;
readonly isFailure: Boolean;
readonly name: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly providerExecuted: withDecodingDefault<Boolean>;
readonly result: Unknown;
readonly type: Literal<"tool-result">;
}>

UserMessage

Added in v4.0.0 Source

Schema for validation and encoding of user messages.

Signature

declare const UserMessage: Struct<{
readonly "~effect/ai/Prompt/Message": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Message">>;
readonly content: Union<readonly [decodeTo<NonEmptyArray<toType<Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly text: String;
readonly type: Literal<"text">;
}>>>, String, never, never>, $Array<Union<readonly [Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly text: String;
readonly type: Literal<"text">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<...>>;
readonly data: Union<readonly [..., ..., ...]>;
readonly fileName: optional<String>;
readonly mediaType: String;
readonly options: withDecodingDefault<$Record<..., ...>>;
readonly type: Literal<"file">;
}>]>>]>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly role: Literal<"user">;
}>

Schema for validation and encoding of user message content parts.

Signature

declare const UserMessagePart: Union<readonly [Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly text: String;
readonly type: Literal<"text">;
}>, Struct<{
readonly "~effect/ai/Prompt/Part": withDecodingDefaultKey<Literal<"~effect/ai/Prompt/Part">>;
readonly data: Union<readonly [String, Uint8Array, URL]>;
readonly fileName: optional<String>;
readonly mediaType: String;
readonly options: withDecodingDefault<$Record<String, NullOr<Codec<Json, Json, never, never>>>>;
readonly type: Literal<"file">;
}>]>

Utility Types

A utility type for specifying the parameters required to construct a specific message for a prompt.

Signature

type MessageConstructorParams<M extends Message> = Omit<M, typeof MessageTypeId | "role" | "options"> & {
readonly options?: M["options"];
}

A utility type for specifying the parameters required to construct a specific part of a prompt.

Signature

type PartConstructorParams<P extends Part> = Omit<P, typeof PartTypeId | "type" | "options"> & {
readonly options?: Part["options"];
}