Open-Source Alternative to Claude API - Runcrate

Use anthropic/claude-4-sonnet on Runcrate with the same OpenAI-compatible interface you already know. One API key gives you Claude plus 170+ other models — switch between them by changing a single string. No separate Anthropic account, no separate billing.

Why use Claude through Runcrate

	Direct Anthropic API	Runcrate
API format	Anthropic-specific SDK	OpenAI-compatible (drop-in)
Models available	Claude only	Claude + DeepSeek + Llama + Qwen + 170 more
API keys	One per provider	One key for everything
Billing	Separate per provider	Single credit balance
Switching models	Rewrite integration code	Change one string

Same code, different base URL

If you already use the OpenAI SDK, switching to Claude on Runcrate is a one-line change:

curl https://api.runcrate.ai/v1/chat/completions \
  -H "Authorization: Bearer rc_live_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-4-sonnet",
    "messages": [
      {"role": "user", "content": "Compare REST and GraphQL in three sentences."}
    ],
    "max_tokens": 256
  }'

from openai import OpenAI

client = OpenAI(
    base_url="https://api.runcrate.ai/v1",
    api_key="rc_live_YOUR_API_KEY",
)

response = client.chat.completions.create(
    model="anthropic/claude-4-sonnet",
    messages=[{"role": "user", "content": "Compare REST and GraphQL in three sentences."}],
    max_tokens=256,
)
print(response.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.runcrate.ai/v1",
  apiKey: "rc_live_YOUR_API_KEY",
});

const response = await client.chat.completions.create({
  model: "anthropic/claude-4-sonnet",
  messages: [{ role: "user", content: "Compare REST and GraphQL in three sentences." }],
  max_tokens: 256,
});

console.log(response.choices[0].message.content);

Switch models without changing code

The real advantage: swap model and the rest of your code stays identical.

from openai import OpenAI

client = OpenAI(
    base_url="https://api.runcrate.ai/v1",
    api_key="rc_live_YOUR_API_KEY",
)

models = [
    "anthropic/claude-4-sonnet",
    "deepseek-ai/DeepSeek-V4-Pro",
    "meta-llama/Llama-4-Scout-17B-16E-Instruct",
]

for model in models:
    response = client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": "What is the capital of France?"}],
        max_tokens=32,
    )
    print(f"{model}: {response.choices[0].message.content}")

Next steps

Route between AI models — use different models for different tasks in the same app.
Model catalog — see all 170+ models, pricing, and context windows.
SDKs overview — Python, TypeScript, and Vercel AI SDK setup.