Tanstack AI Solid API | TanStack AI Docs

SolidJS primitives for TanStack AI, providing convenient SolidJS bindings for the headless client.

Installation

bash

npm install @tanstack/ai-solid

npm install @tanstack/ai-solid

useChat(options?)

Main primitive for managing chat state in SolidJS with full type safety.

typescript

import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";
import { 
  clientTools, 
  createChatClientOptions, 
  type InferChatMessages 
} from "@tanstack/ai-client";

function ChatComponent() {
  // Create client tool implementations
  const updateUI = updateUIDef.client((input) => {
    setNotification(input.message);
    return { success: true };
  });

  // Create typed tools array (no 'as const' needed!)
  const tools = clientTools(updateUI);

  const chatOptions = createChatClientOptions({
    connection: fetchServerSentEvents("/api/chat"),
    tools,
  });

  // Fully typed messages!
  type ChatMessages = InferChatMessages<typeof chatOptions>;

  const { messages, sendMessage, isLoading, error, addToolApprovalResponse } =
    useChat(chatOptions);

  return <div>{/* Chat UI with typed messages */}</div>;
}

import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";
import { 
  clientTools, 
  createChatClientOptions, 
  type InferChatMessages 
} from "@tanstack/ai-client";

function ChatComponent() {
  // Create client tool implementations
  const updateUI = updateUIDef.client((input) => {
    setNotification(input.message);
    return { success: true };
  });

  // Create typed tools array (no 'as const' needed!)
  const tools = clientTools(updateUI);

  const chatOptions = createChatClientOptions({
    connection: fetchServerSentEvents("/api/chat"),
    tools,
  });

  // Fully typed messages!
  type ChatMessages = InferChatMessages<typeof chatOptions>;

  const { messages, sendMessage, isLoading, error, addToolApprovalResponse } =
    useChat(chatOptions);

  return <div>{/* Chat UI with typed messages */}</div>;
}

Options

Extends ChatClientOptions from @tanstack/ai-client:

connection - Connection adapter (required)
tools? - Array of client tool implementations (with .client() method)
initialMessages? - Initial messages array
id? - Unique identifier for this chat instance
body? - Additional body parameters to send
onResponse? - Callback when response is received
onChunk? - Callback when stream chunk is received
onFinish? - Callback when response finishes
onError? - Callback when error occurs
streamProcessor? - Stream processing configuration

Note: Client tools are now automatically executed - no onToolCall callback needed!

Returns

typescript

interface UseChatReturn {
  messages: Accessor<UIMessage[]>;
  sendMessage: (content: string) => Promise<void>;
  append: (message: ModelMessage | UIMessage) => Promise<void>;
  addToolResult: (result: {
    toolCallId: string;
    tool: string;
    output: any;
    state?: "output-available" | "output-error";
    errorText?: string;
  }) => Promise<void>;
  addToolApprovalResponse: (response: {
    id: string;
    approved: boolean;
  }) => Promise<void>;
  reload: () => Promise<void>;
  stop: () => void;
  isLoading: Accessor<boolean>;
  error: Accessor<Error | undefined>;
  setMessages: (messages: UIMessage[]) => void;
  clear: () => void;
}

interface UseChatReturn {
  messages: Accessor<UIMessage[]>;
  sendMessage: (content: string) => Promise<void>;
  append: (message: ModelMessage | UIMessage) => Promise<void>;
  addToolResult: (result: {
    toolCallId: string;
    tool: string;
    output: any;
    state?: "output-available" | "output-error";
    errorText?: string;
  }) => Promise<void>;
  addToolApprovalResponse: (response: {
    id: string;
    approved: boolean;
  }) => Promise<void>;
  reload: () => Promise<void>;
  stop: () => void;
  isLoading: Accessor<boolean>;
  error: Accessor<Error | undefined>;
  setMessages: (messages: UIMessage[]) => void;
  clear: () => void;
}

Note: Unlike React, messages, isLoading, and error are SolidJS Accessor functions, so you need to call them to get their values (e.g., messages() instead of just messages).

Connection Adapters

Re-exported from @tanstack/ai-client for convenience:

typescript

import {
  fetchServerSentEvents,
  fetchHttpStream,
  stream,
  type ConnectionAdapter,
} from "@tanstack/ai-solid";

import {
  fetchServerSentEvents,
  fetchHttpStream,
  stream,
  type ConnectionAdapter,
} from "@tanstack/ai-solid";

Example: Basic Chat

typescript

import { createSignal, For } from "solid-js";
import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";

export function Chat() {
  const [input, setInput] = createSignal("");

  const { messages, sendMessage, isLoading } = useChat({
    connection: fetchServerSentEvents("/api/chat"),
  });

  const handleSubmit = (e: Event) => {
    e.preventDefault();
    if (input().trim() && !isLoading()) {
      sendMessage(input());
      setInput("");
    }
  };

  return (
    <div>
      <div>
        <For each={messages()}>
          {(message) => (
            <div>
              <strong>{message.role}:</strong>
              <For each={message.parts}>
                {(part) => {
                  if (part.type === "thinking") {
                    return (
                      <div class="text-sm text-gray-500 italic">
                        💭 Thinking: {part.content}
                      </div>
                    );
                  }
                  if (part.type === "text") {
                    return <span>{part.content}</span>;
                  }
                  return null;
                }}
              </For>
            </div>
          )}
        </For>
      </div>
      <form onSubmit={handleSubmit}>
        <input
          value={input()}
          onInput={(e) => setInput(e.currentTarget.value)}
          disabled={isLoading()}
        />
        <button type="submit" disabled={isLoading()}>
          Send
        </button>
      </form>
    </div>
  );
}

import { createSignal, For } from "solid-js";
import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";

export function Chat() {
  const [input, setInput] = createSignal("");

  const { messages, sendMessage, isLoading } = useChat({
    connection: fetchServerSentEvents("/api/chat"),
  });

  const handleSubmit = (e: Event) => {
    e.preventDefault();
    if (input().trim() && !isLoading()) {
      sendMessage(input());
      setInput("");
    }
  };

  return (
    <div>
      <div>
        <For each={messages()}>
          {(message) => (
            <div>
              <strong>{message.role}:</strong>
              <For each={message.parts}>
                {(part) => {
                  if (part.type === "thinking") {
                    return (
                      <div class="text-sm text-gray-500 italic">
                        💭 Thinking: {part.content}
                      </div>
                    );
                  }
                  if (part.type === "text") {
                    return <span>{part.content}</span>;
                  }
                  return null;
                }}
              </For>
            </div>
          )}
        </For>
      </div>
      <form onSubmit={handleSubmit}>
        <input
          value={input()}
          onInput={(e) => setInput(e.currentTarget.value)}
          disabled={isLoading()}
        />
        <button type="submit" disabled={isLoading()}>
          Send
        </button>
      </form>
    </div>
  );
}

Example: Tool Approval

typescript

import { For, Show } from "solid-js";
import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";

export function ChatWithApproval() {
  const { messages, sendMessage, addToolApprovalResponse } = useChat({
    connection: fetchServerSentEvents("/api/chat"),
  });

  return (
    <div>
      <For each={messages()}>
        {(message) => (
          <For each={message.parts}>
            {(part) => (
              <Show
                when={
                  part.type === "tool-call" &&
                  part.state === "approval-requested" &&
                  part.approval
                }
              >
                <div>
                  <p>Approve: {part.name}</p>
                  <button
                    onClick={() =>
                      addToolApprovalResponse({
                        id: part.approval!.id,
                        approved: true,
                      })
                    }
                  >
                    Approve
                  </button>
                  <button
                    onClick={() =>
                      addToolApprovalResponse({
                        id: part.approval!.id,
                        approved: false,
                      })
                    }
                  >
                    Deny
                  </button>
                </div>
              </Show>
            )}
          </For>
        )}
      </For>
    </div>
  );
}

import { For, Show } from "solid-js";
import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";

export function ChatWithApproval() {
  const { messages, sendMessage, addToolApprovalResponse } = useChat({
    connection: fetchServerSentEvents("/api/chat"),
  });

  return (
    <div>
      <For each={messages()}>
        {(message) => (
          <For each={message.parts}>
            {(part) => (
              <Show
                when={
                  part.type === "tool-call" &&
                  part.state === "approval-requested" &&
                  part.approval
                }
              >
                <div>
                  <p>Approve: {part.name}</p>
                  <button
                    onClick={() =>
                      addToolApprovalResponse({
                        id: part.approval!.id,
                        approved: true,
                      })
                    }
                  >
                    Approve
                  </button>
                  <button
                    onClick={() =>
                      addToolApprovalResponse({
                        id: part.approval!.id,
                        approved: false,
                      })
                    }
                  >
                    Deny
                  </button>
                </div>
              </Show>
            )}
          </For>
        )}
      </For>
    </div>
  );
}

Example: Client Tools with Type Safety

typescript

import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";
import { 
  clientTools, 
  createChatClientOptions, 
  type InferChatMessages 
} from "@tanstack/ai-client";
import { updateUIDef, saveToStorageDef } from "./tool-definitions";
import { createSignal, For } from "solid-js";

export function ChatWithClientTools() {
  const [notification, setNotification] = createSignal(null);

  // Create client implementations
  const updateUI = updateUIDef.client((input) => {
    // ✅ input is fully typed!
    setNotification({ message: input.message, type: input.type });
    return { success: true };
  });

  const saveToStorage = saveToStorageDef.client((input) => {
    localStorage.setItem(input.key, input.value);
    return { saved: true };
  });

  // Create typed tools array (no 'as const' needed!)
  const tools = clientTools(updateUI, saveToStorage);

  const { messages, sendMessage } = useChat({
    connection: fetchServerSentEvents("/api/chat"),
    tools, // ✅ Automatic execution, full type safety
  });

  return (
    <div>
      <For each={messages()}>
        {(message) => (
          <For each={message.parts}>
            {(part) => {
              if (part.type === "tool-call" && part.name === "updateUI") {
                // ✅ part.input and part.output are fully typed!
                return <div>Tool executed: {part.name}</div>;
              }
            }}
          </For>
        )}
      </For>
    </div>
  );
}

import { useChat, fetchServerSentEvents } from "@tanstack/ai-solid";
import { 
  clientTools, 
  createChatClientOptions, 
  type InferChatMessages 
} from "@tanstack/ai-client";
import { updateUIDef, saveToStorageDef } from "./tool-definitions";
import { createSignal, For } from "solid-js";

export function ChatWithClientTools() {
  const [notification, setNotification] = createSignal(null);

  // Create client implementations
  const updateUI = updateUIDef.client((input) => {
    // ✅ input is fully typed!
    setNotification({ message: input.message, type: input.type });
    return { success: true };
  });

  const saveToStorage = saveToStorageDef.client((input) => {
    localStorage.setItem(input.key, input.value);
    return { saved: true };
  });

  // Create typed tools array (no 'as const' needed!)
  const tools = clientTools(updateUI, saveToStorage);

  const { messages, sendMessage } = useChat({
    connection: fetchServerSentEvents("/api/chat"),
    tools, // ✅ Automatic execution, full type safety
  });

  return (
    <div>
      <For each={messages()}>
        {(message) => (
          <For each={message.parts}>
            {(part) => {
              if (part.type === "tool-call" && part.name === "updateUI") {
                // ✅ part.input and part.output are fully typed!
                return <div>Tool executed: {part.name}</div>;
              }
            }}
          </For>
        )}
      </For>
    </div>
  );
}

createChatClientOptions(options)

Helper to create typed chat options (re-exported from @tanstack/ai-client).

typescript

import { 
  clientTools, 
  createChatClientOptions, 
  type InferChatMessages 
} from "@tanstack/ai-client";

// Create typed tools array (no 'as const' needed!)
const tools = clientTools(tool1, tool2);

const chatOptions = createChatClientOptions({
  connection: fetchServerSentEvents("/api/chat"),
  tools,
});

type Messages = InferChatMessages<typeof chatOptions>;

import { 
  clientTools, 
  createChatClientOptions, 
  type InferChatMessages 
} from "@tanstack/ai-client";

// Create typed tools array (no 'as const' needed!)
const tools = clientTools(tool1, tool2);

const chatOptions = createChatClientOptions({
  connection: fetchServerSentEvents("/api/chat"),
  tools,
});

type Messages = InferChatMessages<typeof chatOptions>;

Types

Re-exported from @tanstack/ai-client:

UIMessage<TTools> - Message type with tool type parameter
MessagePart<TTools> - Message part with tool type parameter
TextPart - Text content part
ThinkingPart - Thinking content part
ToolCallPart<TTools> - Tool call part (discriminated union)
ToolResultPart - Tool result part
ChatClientOptions<TTools> - Chat client options
ConnectionAdapter - Connection adapter interface
InferChatMessages<T> - Extract message type from options
ChatRequestBody - Request body type

Re-exported from @tanstack/ai:

toolDefinition() - Create isomorphic tool definition
ToolDefinitionInstance - Tool definition type
ClientTool - Client tool type
ServerTool - Server tool type

Next Steps

Getting Started - Learn the basics
Tools Guide - Learn about the isomorphic tool system
Client Tools - Learn about client-side tools