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Claude Opus 4 · OpenAI-compatible · one key, all models

The same Claude Opus 4, 30–50% cheaper

Same Anthropic upstream, same quality — flatkey costs half. Change one line of base_url and your existing OpenAI SDK just works. Try it below, sign in when you are ready.

Anthropic official
$15.00
/ million output tokens
flatkey · same model, same quality
$7.50
/ million output tokens
↓ Save 50% — double your token budget
Playground (edit before sign-up)
model: claude-opus-4temp 0.7 · 1024 tok
temperature 0.7max_tokens 1024top_p 1.0
▶ Sign in to runGoogle / GitHub one-click · no credit card to start
Est. this run ≈ $0.004 (flatkey · official ≈ $0.008)
Pricing vs official
Opus 4 output$7.5 $15
Sonnet 4 output$7.5 $15
Haiku output$2.0 $4
Cache reads50% off
CoverageGPT · Gemini · Claude · DeepSeek · Seedance

* Illustrative pricing — see flatkey pricing page

migrate.py — change one line
# Your existing OpenAI code:
client = OpenAI(
  base_url="https://router.flatkey.ai/v1"
  api_key="sk-flatkey-...",
)
client.chat.completions.create(model="claude-opus-4", ...)
First top-up 50% bonus
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