Home › API keys › Anthropic (Claude)
✓ Checked against Anthropic's official pages on 23 September 2026. Screens and prices change: if something looks different, trust what Anthropic shows you.
An Anthropic API key is a secret code that lets TranslateRocket send your site’s text to Claude, Anthropic’s AI model, and get the translation back; you pay Anthropic directly with credit you load in advance.
📖 Words you will meet
- API key: a long secret code that starts with
sk-ant-. Whoever has it can spend your credit, so treat it like a password. - Claude Console: Anthropic’s website for developers, where keys and billing live. It is at platform.claude.com (the old address console.anthropic.com now redirects there).
- Credit: money you load in advance. Each translation takes a small amount from it.
- Token: the unit Anthropic charges by. Roughly, 1 token is about 4 characters of English text.
What you need before you start
- An email address to create a Claude Console account.
- A payment card. API use is paid with prepaid credit: you buy credit before you can use the API.
- A few details about your business: before your first purchase, Anthropic asks for some information about your organisation and how you will use the API.
- About 10 minutes.
Important: a Claude Pro, Max or Team subscription (the chat app at claude.ai) is a separate product. It does not include API access or credit.
Step by step
TranslateRocket – mysite.com.sk-ant-) only once. If you lose it, you cannot see it again: you simply create a new one.Keep the key somewhere safe until you paste it into WordPress (a password manager is ideal). Do not send it by email or chat.
How much it costs
Official price (Anthropic pricing page, checked 23 Sep 2026), per 1 million tokens:
| Model | Text you send (input) | Text you get back (output) |
|---|---|---|
| Claude Haiku 4.5 (TranslateRocket’s default) | $1 | $5 |
| Claude Sonnet 4.6 | $3 | $15 |
| Claude Opus 4.8 | $5 | $25 |
What that means for a small site. Our example: a site of 20 pages with about 600 words each (12,000 words, about 75,000 characters), translated into one language.
- 75,000 characters is about 19,000 tokens (Anthropic’s own rule of thumb: 1 token ≈ 4 characters of English).
- TranslateRocket also sends short instructions with each batch, and translated text is often longer than English. To be safe we count 30,000 tokens in and 30,000 tokens out.
- With Claude Haiku 4.5: 30,000 × $1 / 1,000,000 + 30,000 × $5 / 1,000,000 ≈ $0.18.
- With Claude Sonnet 4.6: about $0.54. With Claude Opus 4.8: about $0.90.
This is an estimate: your real cost depends on how much text your pages have. Text that TranslateRocket has already translated is reused and not sent again.
Is there a free allowance? Anthropic’s help pages describe prepaid credit only; we found no free allowance for the API. Credit expires one year after purchase and is non-refundable. You are charged only for requests that succeed.
Safety (please read)
1. Set a spending limit at Anthropic.
- Go to Settings → Billing: https://platform.claude.com/settings/billing
- In the Spend limits section, click Set limit (or Adjust limit if one is already set).
- Enter a monthly amount, for example $5, and save.
When the limit is reached, requests stop with a message saying you have reached your specified usage limit. Every account also has a monthly cap set by Anthropic (for example $500 on the “Start” tier), but your own lower limit is the one that protects you.
2. Set a limit inside TranslateRocket too. In TranslateRocket → AI Translation, section Usage & limits, fill in Daily character limit (for example 200000). When the limit is reached, AI translation stops until the next day. 0 means no limit.
3. Never share the key. Do not put it in emails, chats, screenshots or support tickets.
4. If you think the key has leaked, disable or delete it.
- Go to https://platform.claude.com/settings/keys
- Find the key. Disable stops it and can be undone (Re-enable); Delete is permanent.
- Create a new key and paste it into TranslateRocket.
- Check your usage on the Billing page for spending you do not recognise.
Where to paste it in TranslateRocket
- In your WordPress dashboard, open TranslateRocket → AI Translation.
- In the Provider & keys box, find the card called Anthropic (Claude).
- Paste your key into the API key field.
- At the top of the box, set Active provider to Anthropic (Claude).
- Optional: the Model field can stay empty (TranslateRocket then uses claude-haiku-4-5). The Load available models button lists the models your key can use.
- Click Save AI settings at the bottom of the page.
The card now shows the Active badge. You can translate from the Translations screen, or page by page in the visual editor.
If something does not work
| What you see | What it usually means | What to do |
|---|---|---|
authentication_error (401) |
The key was copied wrongly, or it was disabled, deleted or has expired. | Paste it again carefully. If it expired or you no longer have it, create a new key. Expired keys cannot be reactivated. |
billing_error (402), or translations stop after working for a while |
A problem with your payment details, or your credit ran out (with no credit left the API stops working). | Go to Settings → Billing, click Buy credits, or update your card with the pencil icon next to it. |
| “You have reached your specified API usage limits” | Your own spend limit did its job. | Raise the limit in Settings → Billing → Spend limits, or wait until the date shown in the message. |
One more tip: Anthropic retires older models from time to time (Claude Haiku 4.5 is listed as “not sooner than October 15, 2026”). If TranslateRocket says a model is not found, click Load available models and pick a current one.
Questions people ask
Is the Claude API free?
We found no free allowance: the Claude API is paid with prepaid credit that you buy in the Claude Console. Credit expires one year after purchase.
Does Claude Pro include API access?
No. Claude Pro, Max and Team (the chat app at claude.ai) are separate products and do not include API access or credit.
Where do I create a Claude API key?
In the Claude Console, Settings → API keys, at platform.claude.com/settings/keys. The old address console.anthropic.com redirects there.
Which Claude model should I use to translate a website?
Claude Haiku 4.5 is TranslateRocket's default and the cheapest: about $0.18 for a 20-page site in one language. Claude Sonnet 4.6 costs about $0.54 for the same site.
Which one should I choose?
See our comparison page for a simple comparison of all five services, and for the free option that needs no key at all.
Other guides: OpenAI · Google Gemini · DeepL · Google Cloud Translation · Which one should I choose?
