Switch from Anthropic Claude API
in 60 seconds

Step 1: Get Brainiall key (15s)

Sign up at app.brainiall.com/quickstart. Get brnl-... key.

Step 2: Replace anthropic SDK with openai (30s)

Before (Anthropic SDK)

import anthropic

client = anthropic.Anthropic(api_key="sk-ant-...")

response = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello!"}]
)
print(response.content[0].text)

After (OpenAI SDK + Brainiall)

from openai import OpenAI

client = OpenAI(
    base_url="https://api.brainiall.com/v1",
    api_key="brnl-..."
)

response = client.chat.completions.create(
    model="claude-sonnet-4-6",  # also try gpt-5, gemini-3-pro
    messages=[{"role": "user", "content": "Hello!"}]
)
print(response.choices[0].message.content)

Anthropic API differences to watch

• Method name: messages.create → chat.completions.create (OpenAI standard)
• Response shape: response.content[0].text → response.choices[0].message.content
• System message: Anthropic uses separate system= param. OpenAI/Brainiall: just add {"role": "system", "content": ...} to messages array.
• Tool use: Identical JSON schema. Function calling works seamlessly.
• Streaming: SSE format identical. stream=True works.
• Models: Brainiall normalizes version strings (no -20250929 suffix). Use claude-sonnet-4-6, claude-opus-4-7, claude-haiku-4-5.

Why Anthropic users switch to Brainiall

Claude models available via Brainiall

Migrate Claude → Brainiall in 60 sec

7-day free trial. All Claude models + 100 more. $5.99/mo flat after.

vs Switch from OpenAI · 60s quickstart · Best LLM 2026