How to Integrate Fastio API with Next.js Applications

Next.js tops React frameworks for production apps. The @vercel/next package pulls over 14 million downloads monthly on npm. Server Actions work well with Fastio's REST API at https://api.fast.io/current/. All server-side. Client apps stay light. No SDK bloat. Server Actions manage uploads and creations without key exposure. A 14-day Business Trial requiring a credit card is available. Good for Next.js agent workflows. See: Fastio Workspaces, Fastio Collaboration, Fastio AI.

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More on this subject: Agent Integrations and APIs (96 guides)

Sign up at Fastio. Create an account and start a 14-day Business Trial.

Generate an API key from your Fastio account dashboard. Create one with full permissions.

Add FASTIO_API_KEY to .env.local. Next.js reads it server-side.

Base: https://api.fast.io/current/. Bearer auth on all.

No extra installs. Just fetch.

Set up Fastio calls in Next.js Server Actions with these steps.

1. Server Action file. app/actions/fastio.ts:

'use server'; const API_BASE = 'https://api.fast.io/current/';
const API_KEY = process.env.FASTIO_API_KEY!; export async function createWorkspace(formData: FormData) { const name = formData.get('name') as string; const folderName = formData.get('folderName') as string; const response = await fetch(`${API_BASE}org/me/workspaces/`, { method: 'POST', headers: { 'Authorization': `Bearer ${API_KEY}`, 'Content-Type': 'application/x-www-form-urlencoded', }, body: new URLSearchParams({ name, folder_name: folderName }), }); if (!response.ok) throw new Error('Failed to create workspace'); return response.json;
}

2. Form usage. app/page.tsx:

import { createWorkspace } from './actions/fastio'; export default function Home { return ( <form action={createWorkspace}> <input name="name" placeholder="Workspace Name" required /> <input name="folderName" placeholder="Folder Name" required /> <button type="submit">Create Workspace</button> </form> );
}

3. Auth setup. For initial auth:

export async function getAuthToken { const response = await fetch(`${API_BASE}user/auth/`, { method: 'GET', headers: { Authorization: `Basic ${btoa(`${process.env.FASTIO_EMAIL}:${process.env.FASTIO_PASSWORD}`)}` }, }); const data = await response.json; return data.auth_token;
}

Use JWT after.

4. Revalidate caches. Chunked file uploads.

export async function uploadFile(formData: FormData, workspaceId: string) { const file = formData.get('file') as File; // Chunk logic here - check Fastio docs
}

npm run dev. Form submit. Check dashboard.

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Use vercel --prod for deploy.

Env vars: FASTIO_API_KEY in Vercel Settings > Environment Variables. Fast API calls.

Caching: revalidateTag for fine control.

Logs: Vercel shows errors. Pair with Fastio activity feeds. vercel.json example:

{ "functions": { "app/**/*.ts": { "runtime": "nodejs20.x" } }
}

Server Actions keep keys server-side in env vars. Client never sees them.

Vercel env vars for deploy.

Scoped access: PKCE OAuth in actions. Skip long-lived keys.

Rotate via Fastio settings.

Track usage: GET /org/me/billing/usage/limits/credits/.

Read API route.

app/api/fastio/workspaces/route.ts:

import { NextResponse } from 'next/server';

export async function GET() {
  const res = await fetch(`${API_BASE}org/me/workspaces/`, {
    headers: { Authorization: `Bearer ${API_KEY}` },
  });
  const data = await res.json();
  return NextResponse.json(data);
}

Client fetch /api/fastio/workspaces.

AI query Server Action.

Workspace intelligence on first.

export async function queryWorkspace(workspaceId: string, question: string) {
  const res = await fetch(`${API_BASE}workspaces/${workspaceId}/ai/chat/`, {
    method: 'POST',
    headers: { Authorization: `Bearer ${API_KEY}`, 'Content-Type': 'application/x-www-form-urlencoded' },
    body: new URLSearchParams({ type: 'chat_with_files', query_text: question }),
  });
  return res.json();
}

Response has citations.

Errors: Try/catch fetches. Check result: false.

Backoff on rate limits.

Agent Dashboard: List workspaces. Upload files. Transfer ownership.

POST /org/{orgId}/transfer/token/create/. Share https://go.fast.io/claim?token={token}.

File Pipeline: Web import URL. AI query. Share output.

upload/web-import then ai/chat.

Multi-Agent: Version history and activity polling.

Builds production agent apps.

Errors: {"result": false, "error": {"code": 1650, "text": "..."}}. Refresh JWT or rotate key. Implement exponential backoff on rate limit errors. List with org/me/workspaces/.

AI empty: Intelligence off or ai_state not ready. PATCH intelligence=on.

Silent fails: Vercel/Next logs. Add try/catch, console.error. Codes: Fastio Error Reference.