Anthropic SDK Integration

Verlon AI provides an Anthropic-compatible API endpoint. You can use the official Anthropic SDK by pointing it to Verlon’s base URL instead of Anthropic’s.

Quick Start

Prerequisites

Verlon AI account (sign up)
Verlon API key from your Dashboard
A configured gate (gate UUID)

Installation

npm install @anthropic-ai/sdk

pnpm add @anthropic-ai/sdk

yarn add @anthropic-ai/sdk

Configuration

Update your Anthropic client initialization - just 2 lines:

import Anthropic from '@anthropic-ai/sdk';

const anthropic = new Anthropic({
  apiKey: process.env.ANTHROPIC_API_KEY,
});

import Anthropic from '@anthropic-ai/sdk';

const anthropic = new Anthropic({
  baseURL: 'https://api.verlon.ai',  // ✓ Add this
  apiKey: process.env.VERLON_API_KEY,   // ✓ Change this
});

Making Requests

Verlon supports three ways to specify your gate:

Using gateId (Recommended)
Using model field
Using header

// @ts-ignore - gateId is a Verlon AI extension
const response = await anthropic.messages.create({
  gateId: process.env.GATE_ID,
  max_tokens: 1024,
  messages: [
    { role: 'user', content: 'Hello!' }
  ],
});

Requires @ts-ignore comment for TypeScript, but provides the clearest intent.

const response = await anthropic.messages.create({
  model: process.env.GATE_ID,  // Gate UUID as model
  max_tokens: 1024,
  messages: [
    { role: 'user', content: 'Hello!' }
  ],
});

No TypeScript errors, works seamlessly with existing code.

const anthropic = new Anthropic({
  baseURL: 'https://api.verlon.ai',
  apiKey: process.env.VERLON_API_KEY,
  defaultHeaders: {
    'X-Verlon-Gate-Id': process.env.GATE_ID,
  },
});

// Then make requests without specifying gateId
const response = await anthropic.messages.create({
  max_tokens: 1024,
  messages: [
    { role: 'user', content: 'Hello!' }
  ],
});

Cleanest for TypeScript - set once, use everywhere.

Streaming Example

Streaming works exactly like the standard Anthropic SDK:

const stream = await anthropic.messages.create({
  gateId: process.env.GATE_ID,
  max_tokens: 1024,
  messages: [
    { role: 'user', content: 'Tell me a joke.' }
  ],
  stream: true,
});

for await (const event of stream) {
  if (event.type === 'content_block_delta' && event.delta.type === 'text_delta') {
    process.stdout.write(event.delta.text);
  }
}

What’s Supported

Streaming

Full support for stream: true with identical behavior to Anthropic

Tool Use

Works across all providers - Verlon handles format conversion

Vision

Image inputs in messages fully supported

All Message Types

System prompts, user, and assistant messages all supported

Standard Parameters

temperature, max_tokens, top_p, and other Anthropic parameters

Usage & Cost Tracking

Standard response.usage with token counts, plus Verlon’s cost field

Language Examples

import Anthropic from '@anthropic-ai/sdk';

const anthropic = new Anthropic({
  baseURL: 'https://api.verlon.ai',
  apiKey: process.env.VERLON_API_KEY,
});

const response = await anthropic.messages.create({
  gateId: process.env.GATE_ID,
  max_tokens: 1024,
  messages: [
    { role: 'user', content: 'Hello!' }
  ],
});

console.log(response.content[0].text);

from anthropic import Anthropic

client = Anthropic(
    base_url="https://api.verlon.ai",
    api_key="sk-vrln-your_api_key",
)

response = client.messages.create(
    model="your-gate-uuid",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Hello!"}
    ]
)

print(response.content[0].text)

const Anthropic = require('@anthropic-ai/sdk');

const anthropic = new Anthropic({
  baseURL: 'https://api.verlon.ai',
  apiKey: process.env.VERLON_API_KEY,
});

async function chat() {
  const response = await anthropic.messages.create({
    gateId: process.env.GATE_ID,
    max_tokens: 1024,
    messages: [
      { role: 'user', content: 'Hello!' }
    ],
  });

  console.log(response.content[0].text);
}

chat();

curl https://api.verlon.ai/v1/messages \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-vrln-your_api_key" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "gateId": "your-gate-uuid",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Hello!"}
    ]
  }'

Migration Guide

Follow these steps to migrate an existing Anthropic application:

1. Update Client Initialization

Find where you initialize the Anthropic client and update it:

// Before
const anthropic = new Anthropic({ apiKey: process.env.ANTHROPIC_API_KEY });

// After
const anthropic = new Anthropic({
  baseURL: 'https://api.verlon.ai',
  apiKey: process.env.VERLON_API_KEY,
});

2. Add Gate ID

Add gateId to your message calls:

// Before
const response = await anthropic.messages.create({
  model: 'claude-3-5-sonnet-20241022',
  max_tokens: 1024,
  messages: [...],
});

// After
const response = await anthropic.messages.create({
  gateId: process.env.GATE_ID,  // ✓ Add this
  max_tokens: 1024,
  messages: [...],               // Everything else stays the same
});

3. Update Environment Variables

.env

VERLON_API_KEY=sk-vrln-your_key
GATE_ID=your-gate-uuid

4. Test & Deploy

Test in development
Verify requests appear in Verlon dashboard
Check cost tracking is working
Deploy to production

Easy Rollback: If anything breaks, revert the 2 changes (baseURL + apiKey) - takes 30 seconds.

Advanced Usage

Multiple Gates

Use different gates based on the task:

const COMPLEX_TASK_GATE = 'uuid-for-claude-opus';
const SIMPLE_TASK_GATE = 'uuid-for-claude-haiku';

async function complexTask(prompt: string) {
  return await anthropic.messages.create({
    gateId: COMPLEX_TASK_GATE,
    max_tokens: 4096,
    messages: [{ role: 'user', content: prompt }],
  });
}

async function simpleTask(prompt: string) {
  return await anthropic.messages.create({
    gateId: SIMPLE_TASK_GATE,
    max_tokens: 1024,
    messages: [{ role: 'user', content: prompt }],
  });
}

Environment-Specific Configuration

const baseURL = process.env.NODE_ENV === 'production'
  ? 'https://api.verlon.ai'
  : 'http://localhost:3001';  // Local Verlon API for dev

const anthropic = new Anthropic({ baseURL, apiKey: process.env.VERLON_API_KEY });

Error Handling

try {
  const response = await anthropic.messages.create({
    gateId: process.env.GATE_ID,
    max_tokens: 1024,
    messages: [{ role: 'user', content: 'Hello!' }],
  });

  console.log(response.content[0].text);
} catch (error) {
  if (error.status === 404) {
    console.error('Gate not found - check your GATE_ID');
  } else if (error.status === 429) {
    console.error('Rate limit exceeded');
  } else {
    console.error('Request failed:', error.message);
  }
}

How It Works

You send → Anthropic SDK request to https://api.verlon.ai/v1/messages
Verlon receives → Validates gate, applies routing rules
Verlon routes → Sends to the model configured in your gate (Claude, GPT, Gemini, etc.)
Provider responds → Returns response in provider’s format
Verlon normalizes → Converts back to Anthropic format
You receive → Standard Anthropic response with added cost/metadata

Your code doesn’t know the difference.

FAQ

Do I need to change my code?

No. Just change baseURL and apiKey in the Anthropic client initialization.

Can I still use Anthropic directly?

Yes. Just revert baseURL and apiKey to Anthropic values.

Does streaming work?

Yes. stream: true works exactly like Anthropic.

Can I use GPT or Gemini?

Yes. Configure your gate to use any model — your code stays the same.

What about tool use?

Fully supported. Verlon handles the conversion across all providers.

Do I need the Verlon SDK?

No. This approach uses only the Anthropic SDK.

Comparison: Anthropic SDK vs Verlon SDK

Feature	Anthropic SDK + Verlon	Verlon SDK
Migration Effort	2 lines of code	Full refactor
API Format	Anthropic format	Verlon native format
Use Case	Drop-in replacement	New projects
Multi-modal	Chat only	Chat, image, video, audio
Streaming	✓	✓
Tool Use	✓	✓
Cost Tracking	✓	✓
Admin Operations	✗	✓ (via Admin SDK)

Recommendation:

Existing Anthropic apps → Use Anthropic SDK + Verlon (this guide)
New projects → Use Verlon SDK for full feature set

Next Steps

Create a Gate

Set up routing rules and configure models

View Request Logs

Monitor your API usage and costs

Configure Fallbacks

Learn about fallback strategies

Verlon SDK

Explore the full-featured Verlon SDK

Getting Started

SDK Reference

Platform

Integrations

Provider Compatibility

Anthropic SDK Integration

Quick Start

Prerequisites

Installation

Configuration

Making Requests

Streaming Example

What’s Supported

Language Examples

Migration Guide

1. Update Client Initialization

2. Add Gate ID

3. Update Environment Variables

4. Test & Deploy

Advanced Usage

Multiple Gates

Environment-Specific Configuration

Error Handling

How It Works

FAQ

Comparison: Anthropic SDK vs Verlon SDK

Next Steps

Create a Gate

View Request Logs

Configure Fallbacks

Verlon SDK

​Quick Start

​Prerequisites

​Installation

​Configuration

​Making Requests

​Streaming Example

​What’s Supported

​Language Examples

​Migration Guide

​1. Update Client Initialization

​2. Add Gate ID

​3. Update Environment Variables

​4. Test & Deploy

​Advanced Usage

​Multiple Gates

​Environment-Specific Configuration

​Error Handling

​How It Works

​FAQ

​Comparison: Anthropic SDK vs Verlon SDK

​Next Steps

Create a Gate

View Request Logs

Configure Fallbacks

Verlon SDK

Quick Start

Prerequisites

Installation

Configuration

Making Requests

Streaming Example

What’s Supported

Language Examples

Migration Guide

1. Update Client Initialization

2. Add Gate ID

3. Update Environment Variables

4. Test & Deploy

Advanced Usage

Multiple Gates

Environment-Specific Configuration

Error Handling

How It Works

FAQ

Comparison: Anthropic SDK vs Verlon SDK

Next Steps