Claude Opus 5
The previous Opus, still available for work that was built and tested on it.
About Claude Opus 5
Opus 5 was Anthropic’s top everyday model from July to September 2026, when Opus 5.5 replaced it. At launch Anthropic’s headline was agent work: on Zapier’s AutomationBench it passed about one and a half times as many tasks as the next-best model at the same cost per task.
Unlike Opus 5.5, its thinking is optional, so it can give a quick answer without reasoning first. That, and stability, are the reasons to stay on it: if a product was tuned on Opus 5, keep it there until you have tested the move.
Where it’s strong
Products already tuned and tested on Opus 5.
Agent and computer-use work where thinking needs to be switchable.
Automating business workflows.
Where to be careful
Anthropic now treats it as a legacy model and recommends Opus 5.5, which it says costs about 40% less on typical work.
Its knowledge stops a month earlier, in May 2026, than the 5.5 models’.
Price
For scale: 1,000 requests of about 3,000 tokens in and 1,000 out cost $46.00 — a long prompt and a page of answer each. Every rate is published and stays the same from one request to the next. See every model.
Specs
claude-opus-5Call it
Use the OpenAI SDK you already have — point it at Roar AI and name the model. Read the docs.
from openai import OpenAI
client = OpenAI(base_url="https://api.roar-ai.com/v1", api_key="roar_live_…")
reply = client.chat.completions.create(
model="claude-opus-5",
messages=[{"role": "user", "content": "Summarise this contract in plain English."}],
)Compare Claude Opus 5
Questions
How much does Claude Opus 5 cost?
Input is $5.75 per 1M tokens; output is $28.75 per 1M tokens. For scale, 1,000 requests of about 3,000 tokens in and 1,000 out cost $46.00. The rate is published and does not change from one request to the next.
Can I use Claude Opus 5 alongside other models?
Yes. Every model on Roar AI is on the same API key and the same monthly invoice, so switching from Claude Opus 5 to another model is a change to one word in your code.
Is Claude Opus 5 open source?
No. Anthropic does not publish the weights, so it is only available through an API like this one.