Claude Opus 5 API pricing

Call claude-opus-5 through RouterPlex's OpenAI-compatible API — vendor list price, 0% markup, billed per token from a prepaid balance. No subscription required.

On cost it sits in the premium band of the catalog: the 31st cheapest of 37 comparable text models, at about $0.75 per 100K-in / 10K-out agent turn — cheaper than 3 others on the same key. Its 1M context window ranks 9th of 37.

Input / 1M tokens
$5.00
Output / 1M tokens
$25.00
Context window
1M
Provider
Anthropic

Example request costs

These examples apply the published input and output token rates directly. Actual cost depends on the tokens your client sends and the model returns.

Short request
$0.075

10K input + 1K output tokens

Agent turn
$0.75

100K input + 10K output tokens

Cheaper and pricier on the same key.

Every model below runs through the same endpoint and the same API key, so moving between them is a one-line model ID change. Costs are for the same 100K-in / 10K-out turn.

Quality is a separate question from price — see Claude Opus 5 benchmark results before optimising on cost alone. Claude Opus 5 reads images; for generating them see GPT Image 2 pricing.

Use it in one request.

curl https://api.routerplex.com/v1/chat/completions \
  -H "Authorization: Bearer $ROUTERPLEX_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-5",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

Works with any OpenAI SDK or tool — just change the base URL. See the quickstart.

Common questions.

How much does the Claude Opus 5 API cost?

Through RouterPlex, Claude Opus 5 costs $5.00 per 1M input tokens and $25.00 per 1M output tokens — the vendor list price with 0% markup, billed per token from a prepaid balance you top up from $5.

What does one Claude Opus 5 agent turn cost?

A 100K-token input with a 10K-token reply costs about $0.75 on Claude Opus 5. That makes it the 31st cheapest of 37 comparable text models on RouterPlex, roughly 69.4× the cost of the cheapest option (DeepSeek V4 Flash).

What is a cheaper alternative to Claude Opus 5?

Kimi K3 from Moonshot is the closest cheaper model on RouterPlex — $0.45 per agent turn against $0.75 for Claude Opus 5, at $3.00/1M input and $15.00/1M output. Both run on the same key and the same endpoint, so switching is a one-line model ID change.

Is Claude Opus 5 cheaper than GPT-5.5?

Yes. Per agent turn, Claude Opus 5 costs about $0.75 against $0.80 for GPT-5.5 — 6% less.

What is the context window of Claude Opus 5?

Claude Opus 5 supports a 1M token context window on RouterPlex, the 9th largest of the 37 models that publish one.

Can I use Claude Opus 5 with the OpenAI SDK?

Yes. RouterPlex serves Claude Opus 5 through an OpenAI-compatible endpoint at https://api.routerplex.com/v1 — point any OpenAI SDK or tool at that base URL with your RouterPlex key and set model to "claude-opus-5".

More from Anthropic.

Compare current API prices and context windows before changing the model ID.

Try Claude Opus 5 in minutes.

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Claude Opus 5 API Pricing · RouterPlex