Claude Opus 5 (Fast) API

Access Claude Opus 5 (Fast) through a simple, OpenAI-compatible API. Change one URL and one key — your existing code works immediately. No SDK changes needed.

65% cheaper than OpenRouter

Claude Opus 5 (Fast) Pricing

Token TypeQubaxRetailSave
Input (per 1M)$4.17$12.0065%
Output (per 1M)$16.68$60.0072%

At $4.17/1M input tokens, Claude Opus 5 (Fast) is one of the most affordable APIs in its class.

Why use Claude Opus 5 (Fast) API on Qubax?

  • Point your OpenAI SDK at https://api.qubax.ai/v1
  • Use model ID: claude-opus-5-fast
  • Generate API keys starting with qbx_live_
  • Full streaming, function calling, and vision support

About Claude Opus 5 (Fast)

Claude Opus 5 (Fast) is a speed-optimized variant of Anthropic's most capable Opus model, offering the same 1M token context window and strong performance across agentic coding, professional knowledge work, and long-horizon reasoning with lower latency. It supports a 1M-token context window and up to 128K output tokens per request. Native capabilities include reasoning, vision, tool calling, structured output, streaming, context caching. On Qubax it is served by 295 independent sellers, so pricing stays competitive and uptime stays high.

1M context window128K max output tokensBuilt-in reasoningVision / image inputFunction & tool callingJSON schema responsesPDF inputWeb search

Claude Opus 5 (Fast) API Access — code example

Python — OpenAI SDK, one-line switchpython
from openai import OpenAI

# Only two lines change vs the official API:
client = OpenAI(
    base_url="https://api.qubax.ai/v1",
    api_key="qbx_live_YOUR_KEY",
)

response = client.chat.completions.create(
    model="claude-opus-5-fast",
    messages=[{"role": "user", "content": "Hello, Claude Opus 5 (Fast)!"}],
)
print(response.choices[0].message.content)

More Anthropic models on Qubax

Get started in 60 seconds

  1. 1Create a free account at qubax.ai/register
  2. 2Add crypto credits (200+ coins, $3 minimum, credits never expire)
  3. 3Generate an API key and set your base URL to https://api.qubax.ai/v1
  4. 4Use model ID claude-opus-5-fast — done!

Claude Opus 5 (Fast) API Access FAQ

How much does Claude Opus 5 (Fast) cost API?

On Qubax, Claude Opus 5 (Fast) costs $4.17 per 1M input tokens and $16.68 per 1M output tokens. 65% cheaper than OpenRouter. Pay with 200+ cryptocurrencies.

Can I use Claude Opus 5 (Fast) with my existing tools?

Yes. Qubax is fully OpenAI-compatible. Change your base URL to api.qubax.ai/v1 and use your Qubax key. Works with Cline, Cursor, OpenCode, LangChain, and any OpenAI SDK.

Do I need a credit card?

No. Qubax accepts 200+ cryptocurrencies. No credit card, no KYC.

Start using Claude Opus 5 (Fast) API

No credit card. Crypto accepted. Credits never expire.

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Claude Opus 5 (Fast) API — 65% off · Qubax AI