Claude Opus in Russia: how to use Opus 5.5 in chat and via API

If you are searching for how to use Claude Opus in Russia, the question is usually not the model itself but access and payment. Check the official services' terms for your country with the provider itself; here we cover the gateway option. Below are three ways to work with Claude Opus 5.5 through the Zukko gateway: in a browser chat, via the API and in Claude Code. Each comes with concrete steps and a cost estimate.

Access from Russia goes through the gateway, and you can top up the balance by SBP, with a MasterCard card or with cryptocurrency.

What Opus 5.5 is and what we know about it

In the Zukko catalogue the model is called claude-opus-5-5. Parameters as of October 18, 2026:

You can check the current list and prices with GET https://api.zukko.pro/v1/models or on the "Models" page in the dashboard. Provider prices change, so treat the figures here as an example for the stated date.

Way 1. Browser chat

The shortest path when you do not need to write code:

1. Sign up at zukko.pro↗ and open the dashboard.
2. Top up the balance (minimum $1). Payment methods are described below.
3. Open the browser chat↗, pick claude-opus-5-5 from the list and start typing.

There is no subscription: you pay for the tokens you actually used. A short question costs a fraction of a cent, while uploading a large document costs noticeably more. For one-off tasks (analysing a text, rewriting a letter, explaining a code fragment) this is enough.

Way 2. API

You need the API when a script, bot or service calls the model. First create a key on the API keys page↗: it starts with fetch_ and is shown in full only once, so save it right away.

A curl request

curl https://api.zukko.pro/v1/messages \
  -H "Authorization: Bearer fetch_your_key" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-opus-5-5",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "Draft a plan to migrate a database from MySQL to PostgreSQL"}]
  }'

The official Anthropic SDK

import anthropic

client = anthropic.Anthropic(
    base_url="https://api.zukko.pro",   # no /v1: the SDK adds the path itself
    api_key="fetch_your_key",
)

message = client.messages.create(
    model="claude-opus-5-5",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Find the bug in this function: ..."}],
)
print(message.content[0].text)
print(message.usage)  # input / output token counts

Pay attention to the address. For the Anthropic SDK and Claude Code the base URL is https://api.zukko.pro without /v1. If you use the OpenAI SDK instead, the address is different: https://api.zukko.pro/v1, and the model is called through chat.completions. Format details are in the Messages API documentation↗.

Way 3. Claude Code

Claude Code is a console agent that reads a project and edits files. To work with Zukko, three environment variables are enough:

export ANTHROPIC_BASE_URL=https://api.zukko.pro
export ANTHROPIC_AUTH_TOKEN=fetch_your_key
export ANTHROPIC_MODEL=claude-opus-5-5
claude

For a Zukko key the variable must be ANTHROPIC_AUTH_TOKEN; the variant with "API_KEY" in its name does not fit here. Step-by-step instructions are in the Claude Code section↗.

What it costs: pricing one task

The request cost formula:

fresh input × input price + cache read × read price + cache write × write price + output × output price

Example 1. A one-off request without cache. You send a 20,000-token file and get a 2,000-token answer.

• Input: 20,000 × $0.8 / 1,000,000 = $0.016
• Output: 2,000 × $4 / 1,000,000 = $0.008
• Total: $0.024

At official prices ($4 / $20) the same request costs $0.08 + $0.04 = $0.12.

Example 2. A Claude Code session with cache. Suppose the session adds up to 50,000 fresh input tokens, 600,000 read from cache, 80,000 written to cache and 20,000 output tokens.

• Fresh input: 50,000 × 0.8 / 1,000,000 = $0.04
• Cache read: 600,000 × 0.08 / 1,000,000 = $0.048
• Cache write: 80,000 × 1 / 1,000,000 = $0.08
• Output: 20,000 × 4 / 1,000,000 = $0.08
• Total: $0.248

The token counts here are illustrative; yours will differ. See real values in the "Usage" section of the dashboard. For Claude, cache is billed at its own prices only in the Anthropic format (/v1/messages, Claude Code, Anthropic SDK). In the OpenAI format all input is billed at the input price. More: prompt caching↗.

How to top up

• SBP. Payment in rubles at the market rate at the moment of payment; the payment page adds an 8.5% fee on top. The amount in dollars you requested is credited to the balance.
• Cryptocurrency. USDT and other coins.
• MasterCard cards. A fee of about 13%, amounts from $2 to $594.

When Opus 5.5 is needed and when something cheaper will do

Opus 5.5 costs $0.8 / $4 per 1M tokens, Sonnet 5.5 costs $0.4 / $2. Opus 5.5 has a higher Intelligence Index (58 versus 48), but the index cannot tell you how a model will perform on your task. A practical order: take 10–20 real examples, run them on both models and compare the result and the cost. If the cheaper one copes, keep the expensive one for hard cases. The pair is covered in detail in Sonnet 5 or Opus 5.5↗.

FAQ

Do I need a separate Anthropic account?

No. A Zukko account and key are enough. The model is called by its Zukko catalogue name (claude-opus-5-5).

Can I call Opus through the OpenAI SDK?

Yes. Any model in the catalogue can be called in either format. But the cache discount for Claude is visible to the gateway only in the Anthropic format, so choose it for long repeated contexts.

What if I get a 402 error?

It means the balance is insufficient: top it up in the dashboard. If you get 401, check the key; if 404 model_not_found, check the model name.

How do I avoid overspending?

Each key can have a daily and a monthly limit in dollars and a list of allowed models. This is good protection in case a script or agent loops.

To get started, create a key in the dashboard, top up the balance and send the first request from the example above.