Next.js Integration

This guide shows how to integrate Doclo into a Next.js application, covering file uploads, API routes, and different execution patterns for production deployments.

Prerequisites

Node.js 18+
Next.js 14+ (App Router)
A Doclo API key

Installation

pnpm add @doclo/client

Project Structure

app/
├── api/
│   ├── process-document/
│   │   └── route.ts        # Sync processing endpoint
│   ├── process-async/
│   │   └── route.ts        # Async processing endpoint
│   └── doclo-webhook/
│       └── route.ts        # Webhook handler
├── components/
│   └── document-uploader.tsx
└── page.tsx

Environment Setup

Create a .env.local file:

DOCLO_API_KEY=dc_live_org123_...
DOCLO_WEBHOOK_SECRET=whsec_...  # For webhook verification

Basic API Route: Synchronous Processing

For documents that process quickly (under 30 seconds):

// app/api/process-document/route.ts
import { NextRequest, NextResponse } from 'next/server';
import { DocloClient } from '@doclo/client';

const client = new DocloClient({
  apiKey: process.env.DOCLO_API_KEY!
});

interface InvoiceOutput {
  invoiceNumber: string;
  total: number;
  currency: string;
  vendor: string;
}

export async function POST(request: NextRequest) {
  try {
    const formData = await request.formData();
    const file = formData.get('file') as File | null;
    const flowId = formData.get('flowId') as string | null;

    if (!file) {
      return NextResponse.json(
        { error: 'No file provided' },
        { status: 400 }
      );
    }

    if (!flowId) {
      return NextResponse.json(
        { error: 'No flowId provided' },
        { status: 400 }
      );
    }

    // Convert file to base64
    const buffer = await file.arrayBuffer();
    const base64 = Buffer.from(buffer).toString('base64');

    // Process synchronously
    const result = await client.flows.run<InvoiceOutput>(flowId, {
      input: {
        document: {
          base64,
          filename: file.name,
          mimeType: file.type || 'application/pdf'
        }
      },
      wait: true,
      timeout: 30000  // 30 second timeout
    });

    return NextResponse.json({
      success: true,
      data: result.output,
      metrics: {
        duration: result.duration,
        cost: result.metrics?.cost
      }
    });

  } catch (error) {
    console.error('Processing error:', error);

    if (error instanceof Error) {
      return NextResponse.json(
        { error: error.message },
        { status: 500 }
      );
    }

    return NextResponse.json(
      { error: 'Processing failed' },
      { status: 500 }
    );
  }
}

Frontend: File Upload Component

// app/components/document-uploader.tsx
'use client';

import { useState } from 'react';

interface ExtractedData {
  invoiceNumber: string;
  total: number;
  currency: string;
  vendor: string;
}

interface ProcessingResult {
  success: boolean;
  data?: ExtractedData;
  error?: string;
  metrics?: {
    duration: number;
    cost: number;
  };
}

export function DocumentUploader({ flowId }: { flowId: string }) {
  const [file, setFile] = useState<File | null>(null);
  const [loading, setLoading] = useState(false);
  const [result, setResult] = useState<ProcessingResult | null>(null);

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!file) return;

    setLoading(true);
    setResult(null);

    try {
      const formData = new FormData();
      formData.append('file', file);
      formData.append('flowId', flowId);

      const response = await fetch('/api/process-document', {
        method: 'POST',
        body: formData
      });

      const data = await response.json();

      if (!response.ok) {
        throw new Error(data.error || 'Processing failed');
      }

      setResult(data);
    } catch (error) {
      setResult({
        success: false,
        error: error instanceof Error ? error.message : 'Unknown error'
      });
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="max-w-md mx-auto p-6">
      <form onSubmit={handleSubmit} className="space-y-4">
        <div>
          <label className="block text-sm font-medium mb-2">
            Upload Document
          </label>
          <input
            type="file"
            accept=".pdf,image/*"
            onChange={(e) => setFile(e.target.files?.[0] || null)}
            className="w-full border rounded p-2"
          />
        </div>

        <button
          type="submit"
          disabled={!file || loading}
          className="w-full bg-blue-600 text-white py-2 rounded disabled:opacity-50"
        >
          {loading ? 'Processing...' : 'Extract Data'}
        </button>
      </form>

      {result && (
        <div className="mt-6 p-4 rounded bg-gray-100">
          {result.success ? (
            <div>
              <h3 className="font-semibold mb-2">Extracted Data</h3>
              <pre className="text-sm overflow-auto">
                {JSON.stringify(result.data, null, 2)}
              </pre>
              {result.metrics && (
                <p className="text-sm text-gray-600 mt-2">
                  Processed in {result.metrics.duration}ms
                </p>
              )}
            </div>
          ) : (
            <p className="text-red-600">{result.error}</p>
          )}
        </div>
      )}
    </div>
  );
}

Async Processing with Webhooks

For longer-running extractions, use async processing:

// app/api/process-async/route.ts
import { NextRequest, NextResponse } from 'next/server';
import { DocloClient } from '@doclo/client';

const client = new DocloClient({
  apiKey: process.env.DOCLO_API_KEY!
});

export async function POST(request: NextRequest) {
  try {
    const formData = await request.formData();
    const file = formData.get('file') as File | null;
    const flowId = formData.get('flowId') as string | null;
    const callbackUrl = formData.get('callbackUrl') as string | null;

    if (!file || !flowId) {
      return NextResponse.json(
        { error: 'Missing required fields' },
        { status: 400 }
      );
    }

    const buffer = await file.arrayBuffer();
    const base64 = Buffer.from(buffer).toString('base64');

    // Start async execution
    const execution = await client.flows.run(flowId, {
      input: {
        document: {
          base64,
          filename: file.name,
          mimeType: file.type || 'application/pdf'
        }
      },
      // Webhook URL for completion notification
      webhookUrl: callbackUrl || `${process.env.NEXT_PUBLIC_URL}/api/doclo-webhook`,
      // Optional metadata to identify this request
      metadata: {
        source: 'nextjs-app',
        uploadedAt: new Date().toISOString()
      }
    });

    return NextResponse.json({
      success: true,
      executionId: execution.id,
      status: execution.status,
      message: 'Processing started. You will be notified when complete.'
    });

  } catch (error) {
    console.error('Processing error:', error);
    return NextResponse.json(
      { error: 'Failed to start processing' },
      { status: 500 }
    );
  }
}

Webhook Handler

Receive completion notifications:

// app/api/doclo-webhook/route.ts
import { NextRequest, NextResponse } from 'next/server';
import { verifyWebhookSignature, parseWebhookEvent } from '@doclo/client';

export async function POST(request: NextRequest) {
  try {
    // Get raw body for signature verification
    const rawBody = await request.text();
    const signature = request.headers.get('x-doclo-signature');

    if (!signature) {
      return NextResponse.json(
        { error: 'Missing signature' },
        { status: 401 }
      );
    }

    // Verify webhook signature
    const isValid = await verifyWebhookSignature(
      rawBody,
      signature,
      process.env.DOCLO_WEBHOOK_SECRET!
    );

    if (!isValid) {
      return NextResponse.json(
        { error: 'Invalid signature' },
        { status: 401 }
      );
    }

    // Parse the event
    const body = JSON.parse(rawBody);
    const event = parseWebhookEvent(body);

    // Handle different event types
    if (event.event === 'execution.completed') {
      console.log('Extraction completed:', event.data.id);
      console.log('Output:', event.data.output);

      // Process the result (e.g., save to database, notify user)
      await handleCompletedExtraction(event.data);

    } else if (event.event === 'execution.failed') {
      console.error('Extraction failed:', event.data.id);
      console.error('Error:', event.data.error);

      // Handle the failure
      await handleFailedExtraction(event.data);
    }

    // Return 200 quickly to acknowledge receipt
    return NextResponse.json({ received: true });

  } catch (error) {
    console.error('Webhook error:', error);
    return NextResponse.json(
      { error: 'Webhook processing failed' },
      { status: 500 }
    );
  }
}

async function handleCompletedExtraction(execution: any) {
  // Save to database
  // await prisma.extraction.update({
  //   where: { executionId: execution.id },
  //   data: {
  //     status: 'completed',
  //     output: execution.output,
  //     completedAt: new Date()
  //   }
  // });

  // Notify user via websocket, email, etc.
  console.log('Processed extraction:', execution.id);
}

async function handleFailedExtraction(execution: any) {
  // Log failure, notify team, retry if appropriate
  console.error('Failed extraction:', execution.id, execution.error);
}

Polling for Results

Alternative to webhooks - poll for completion:

// app/api/check-status/route.ts
import { NextRequest, NextResponse } from 'next/server';
import { DocloClient } from '@doclo/client';

const client = new DocloClient({
  apiKey: process.env.DOCLO_API_KEY!
});

export async function GET(request: NextRequest) {
  const executionId = request.nextUrl.searchParams.get('id');

  if (!executionId) {
    return NextResponse.json(
      { error: 'Missing execution ID' },
      { status: 400 }
    );
  }

  try {
    const execution = await client.runs.get(executionId);

    return NextResponse.json({
      id: execution.id,
      status: execution.status,
      output: execution.status === 'success' ? execution.output : null,
      error: execution.status === 'failed' ? execution.error : null,
      duration: execution.duration
    });

  } catch (error) {
    return NextResponse.json(
      { error: 'Failed to get status' },
      { status: 500 }
    );
  }
}

Frontend polling implementation:

// In your component
async function pollForResult(executionId: string): Promise<any> {
  const maxAttempts = 60;  // 5 minutes at 5-second intervals
  const interval = 5000;

  for (let attempt = 0; attempt < maxAttempts; attempt++) {
    const response = await fetch(`/api/check-status?id=${executionId}`);
    const data = await response.json();

    if (data.status === 'success') {
      return data.output;
    }

    if (data.status === 'failed') {
      throw new Error(data.error?.message || 'Processing failed');
    }

    // Still processing, wait and try again
    await new Promise(resolve => setTimeout(resolve, interval));
  }

  throw new Error('Processing timed out');
}

Error Handling

Handle different error types appropriately:

// app/api/process-document/route.ts
import { NextRequest, NextResponse } from 'next/server';
import {
  DocloClient,
  AuthenticationError,
  ValidationError,
  RateLimitError,
  TimeoutError,
  NotFoundError
} from '@doclo/client';

const client = new DocloClient({
  apiKey: process.env.DOCLO_API_KEY!
});

export async function POST(request: NextRequest) {
  try {
    // ... processing logic

  } catch (error) {
    console.error('Processing error:', error);

    if (error instanceof AuthenticationError) {
      return NextResponse.json(
        { error: 'Invalid API key' },
        { status: 401 }
      );
    }

    if (error instanceof ValidationError) {
      return NextResponse.json(
        { error: `Invalid input: ${error.message}` },
        { status: 400 }
      );
    }

    if (error instanceof RateLimitError) {
      const retryAfter = error.rateLimitInfo?.retryAfter || 60;
      return NextResponse.json(
        { error: 'Rate limit exceeded', retryAfter },
        {
          status: 429,
          headers: { 'Retry-After': String(retryAfter) }
        }
      );
    }

    if (error instanceof TimeoutError) {
      return NextResponse.json(
        { error: 'Processing timed out. Try async processing.' },
        { status: 504 }
      );
    }

    if (error instanceof NotFoundError) {
      return NextResponse.json(
        { error: 'Flow not found' },
        { status: 404 }
      );
    }

    return NextResponse.json(
      { error: 'Processing failed' },
      { status: 500 }
    );
  }
}

Type-Safe Flow Results

Use TypeScript generics for type-safe extraction:

// types/extraction.ts
export interface InvoiceExtraction {
  invoiceNumber: string;
  invoiceDate: string;
  vendor: {
    name: string;
    address: string;
  };
  lineItems: Array<{
    description: string;
    quantity: number;
    amount: number;
  }>;
  total: number;
  currency: string;
}

// In your API route
const result = await client.flows.run<InvoiceExtraction>(flowId, {
  input: { document: { base64, filename, mimeType } },
  wait: true
});

// result.output is typed as InvoiceExtraction
const { invoiceNumber, total, currency } = result.output!;

Server Actions (Next.js 14+)

Use Server Actions for a streamlined approach:

// app/actions/process-document.ts
'use server';

import { DocloClient } from '@doclo/client';

const client = new DocloClient({
  apiKey: process.env.DOCLO_API_KEY!
});

interface ProcessResult {
  success: boolean;
  data?: any;
  error?: string;
}

export async function processDocument(formData: FormData): Promise<ProcessResult> {
  const file = formData.get('file') as File | null;
  const flowId = formData.get('flowId') as string;

  if (!file) {
    return { success: false, error: 'No file provided' };
  }

  try {
    const buffer = await file.arrayBuffer();
    const base64 = Buffer.from(buffer).toString('base64');

    const result = await client.flows.run(flowId, {
      input: {
        document: {
          base64,
          filename: file.name,
          mimeType: file.type
        }
      },
      wait: true,
      timeout: 30000
    });

    return {
      success: true,
      data: result.output
    };

  } catch (error) {
    return {
      success: false,
      error: error instanceof Error ? error.message : 'Processing failed'
    };
  }
}

Use in a component:

// app/components/server-action-uploader.tsx
'use client';

import { processDocument } from '@/app/actions/process-document';
import { useFormStatus } from 'react-dom';

function SubmitButton() {
  const { pending } = useFormStatus();
  return (
    <button
      type="submit"
      disabled={pending}
      className="bg-blue-600 text-white py-2 px-4 rounded"
    >
      {pending ? 'Processing...' : 'Extract'}
    </button>
  );
}

export function ServerActionUploader({ flowId }: { flowId: string }) {
  async function handleAction(formData: FormData) {
    formData.append('flowId', flowId);
    const result = await processDocument(formData);
    console.log('Result:', result);
  }

  return (
    <form action={handleAction}>
      <input type="file" name="file" accept=".pdf,image/*" />
      <SubmitButton />
    </form>
  );
}

Production Considerations

Rate Limiting

Protect your endpoints from abuse:

import { Ratelimit } from '@upstash/ratelimit';
import { Redis } from '@upstash/redis';

const ratelimit = new Ratelimit({
  redis: Redis.fromEnv(),
  limiter: Ratelimit.slidingWindow(10, '1 m'),  // 10 requests per minute
});

export async function POST(request: NextRequest) {
  const ip = request.ip ?? '127.0.0.1';
  const { success, limit, remaining } = await ratelimit.limit(ip);

  if (!success) {
    return NextResponse.json(
      { error: 'Rate limit exceeded' },
      {
        status: 429,
        headers: {
          'X-RateLimit-Limit': String(limit),
          'X-RateLimit-Remaining': String(remaining)
        }
      }
    );
  }

  // Continue with processing...
}

File Size Limits

Configure Next.js body size limits:

// next.config.js
module.exports = {
  experimental: {
    serverActions: {
      bodySizeLimit: '10mb'
    }
  }
};

Caching

Cache flow information:

import { unstable_cache } from 'next/cache';

const getFlowInfo = unstable_cache(
  async (flowId: string) => {
    return await client.flows.get(flowId);
  },
  ['flow-info'],
  { revalidate: 3600 }  // Cache for 1 hour
);

Next Steps

Webhook Handler

Detailed webhook implementation

Error Recovery

Handle failures gracefully

DocloClient

Full client reference

Webhooks

Webhook configuration

Getting Started

Concepts

SDK

Doclo Cloud

Guides

Resources

Next.js Integration

Prerequisites

Installation

Project Structure

Environment Setup

Basic API Route: Synchronous Processing

Frontend: File Upload Component

Async Processing with Webhooks

Webhook Handler

Polling for Results

Error Handling

Type-Safe Flow Results

Server Actions (Next.js 14+)

Production Considerations

Rate Limiting

File Size Limits

Caching

Next Steps

Webhook Handler

Error Recovery

DocloClient

Webhooks

Getting Started

Concepts

SDK

Doclo Cloud

Guides

Resources

​Prerequisites

​Installation

​Project Structure

​Environment Setup

​Basic API Route: Synchronous Processing

​Frontend: File Upload Component

​Async Processing with Webhooks

​Webhook Handler

​Polling for Results

​Error Handling

​Type-Safe Flow Results

​Server Actions (Next.js 14+)

​Production Considerations

​Rate Limiting

​File Size Limits

​Caching

​Next Steps

Webhook Handler

Error Recovery

DocloClient

Webhooks

Prerequisites

Installation

Project Structure

Environment Setup

Basic API Route: Synchronous Processing

Frontend: File Upload Component

Async Processing with Webhooks

Webhook Handler

Polling for Results

Error Handling

Type-Safe Flow Results

Server Actions (Next.js 14+)

Production Considerations

Rate Limiting

File Size Limits

Caching

Next Steps