AI SDK 7 implementation and migration
Apply this skill to ai@7; use ai-sdk to resolve unknown versions and
ai-sdk-6 for v6 maintenance. Match provider and UI package versions to the
project. AI SDK 7 requires Node.js 22+ and AI SDK packages are ESM-only.
Read the resolved ai/docs/, provider docs and installed source/types first;
each ai-sdk.dev/docs/... link in this skill has an offline copy under ai/docs/
(path mapping in ai-sdk). Harness, WorkflowAgent and migration guides live
in ai/docs/03-ai-sdk-harnesses/, 03-agents/07-workflow-agent.mdx and
08-migration-guides/23-migration-guide-7-0.mdx; the companion packages ship
only types. Use official docs or the matching
repository tag when local docs are unavailable. Experimental package APIs need
a fresh check before adding long-lived wrappers.
| Need | Entry point |
| --- | --- |
| In-memory agent loop | ToolLoopAgent from ai |
| Durable agent | WorkflowAgent from @ai-sdk/workflow + workflow 5 |
| Claude Code/Codex/Pi runtime | HarnessAgent from @ai-sdk/harness/agent + adapter + sandbox package |
| OpenTelemetry | registerTelemetry(new OpenTelemetry()), @ai-sdk/otel |
| Stalled calls | timeout: ms or { totalMs, stepMs, firstChunkMs, chunkMs, toolMs } |
Important boundaries
- Text functions and ToolLoopAgent use
instructions; loop limits useisStepCount. Core, agent and server UI-stream helpers useonEnd/onStepEnd(onFinishremains a deprecated alias); clientuseChat/ChatkeepsonFinish. prepareStepinstruction/message overrides carry forward. Results such asusageand tool arrays aggregate all steps;finalSteppreserves final-step access, and is awaited for streams.- Use
runtimeContextfor server loop state and schema-validatedtoolsContextfor per-tool state. Neither is model-visible merely by being context. - Approval, persistence and lifecycle differ across ToolLoopAgent, WorkflowAgent, HarnessAgent and provider-executed tools. Choose the runtime for the actual durability/permission requirements.
- Resolve model IDs and capabilities from the configured provider. Avoid
overlapping reasoning settings: provider options can override top-level
reasoning.
Core shape
Checked with ai@7.0.124, @ai-sdk/react@4.0.127, zod@4.6.5, React 19 and
TypeScript 5.9: tsc --noEmit, plus a mock-model run through one tool step and
the follow-up answer. A string model resolves through the AI Gateway.
// app/api/chat/route.ts
import { convertToModelMessages, createUIMessageStreamResponse, isStepCount, streamText, tool,
toUIMessageStream, validateUIMessages, type InferUITools, type UIDataTypes, type UIMessage } from 'ai';
import { z } from 'zod';
const tools = {
weather: tool({
inputSchema: z.object({ city: z.string() }),
execute: async ({ city }) => ({ city, celsius: 21 }),
}),
};
export type ChatMessage = UIMessage<never, UIDataTypes, InferUITools<typeof tools>>;
export async function POST(req: Request) {
const { messages } = await req.json();
const uiMessages = await validateUIMessages<ChatMessage>({ messages, tools });
const result = streamText({
model: 'provider/model-id', // configured gateway ID, or a provider instance
instructions: 'Answer briefly.',
messages: await convertToModelMessages(uiMessages),
tools,
stopWhen: isStepCount(5),
});
return createUIMessageStreamResponse({ stream: toUIMessageStream({ stream: result.stream }) });
}
// app/page.tsx
'use client';
import { useChat } from '@ai-sdk/react';
import { DefaultChatTransport } from 'ai';
import type { ChatMessage } from './api/chat/route';
const transport = new DefaultChatTransport<ChatMessage>({ api: '/api/chat' });
export default function Chat() {
const { messages, sendMessage, status } = useChat<ChatMessage>({ transport });
return (
<form action={(form) => void sendMessage({ text: String(form.get('text')) })}>
{messages.map((m) => <div key={m.id}>{m.parts.map((part, i) =>
part.type === 'text' ? <p key={i}>{part.text}</p>
: part.type === 'tool-weather' && part.state === 'output-available'
? <p key={i}>{part.output.city}: {part.output.celsius} °C</p> : null)}</div>)}
<input name="text" disabled={status === 'submitted' || status === 'streaming'} />
</form>
);
}
The v6 spellings (system, stepCountIs, result.toUIMessageStreamResponse())
still compile in 7.0.124; system and the response method are deprecated.
Read for the feature
- Agents: in-memory/durable execution and context.
- Harnesses: runtime-owned sessions and permissions.
- Core functions: output, stream and result contracts.
- Tools: approval boundaries, MCP Apps and sandbox handles.
- UI hooks: UI streams, approval and resumption.
- Migration: semantic changes and codemods.
- Telemetry: registration and data controls.
- Media/files: provider references and capability gates.
- Examples: current official implementations.
Typecheck and exercise the changed multi-turn, tool, stream or resume path. A successful compile does not prove approval policy or persistence behavior.