Your API Key
How to get one – and what it pays for
Why do I need an API Key?
CodAs is powered by Claude, an AI model developed by Anthropic. Every time you submit a coding request, CodAs sends your question – together with the entire ICHI vocabulary and reference rules – to Anthropic's servers, where Claude processes it and returns a result.
This processing is not free. Anthropic charges a small fee per request, billed directly to whoever owns the API Key used.
Step-by-step: Getting your API Key
Go to console.anthropic.com and sign up with your email address.
Anthropic will send you a confirmation email. Click the link inside to activate your account.
Go to Settings → Billing and add a credit card. You will only be charged for what you actually use – there is no subscription or monthly fee.
Go to Settings → API Keys and click "Create Key". Give it a name (e.g. "CodAs") and copy the key immediately – Anthropic will only show it once.
Paste the key into the API Key field on the CodAs home page. It is never stored on any server – it lives only in your browser session.
What does it cost?
Anthropic charges per token – a token being roughly ¾ of a word. Every request has two parts that are billed separately:
- Input tokens: Everything sent to Claude – your question, the ICHI vocabulary, the reference guide, all the rules.
- Output tokens: Everything Claude sends back – the generated code, the justification, the explanation.
Approximate cost per request using Claude Sonnet 4 (the default model):
| What you send | Approx. cost |
|---|---|
| A single, short coding request | ~ $0.20 – $0.35 |
| A complex request with follow-up questions | ~ $0.50 – $1.00 |
| Claude Opus 4 (highest quality, optional) | ~ $1.50 – $3.00 |
These are estimates. Your actual costs depend on how much text you send and how detailed the response is.
Why do costs vary between requests?
The main cost driver is not your question – it is the ICHI data that CodAs sends with every single request.
To generate correct post-coordinated ICHI codes, Claude needs the complete picture every time: all Action elements, all Target elements, all Means elements, all Extension codes, and all the coding rules from the Reference Guide. This amounts to a very large block of text – sent fresh with each request.
Unlike a human expert who remembers what they learned, an AI model has no persistent memory between sessions. Each request starts from zero. CodAs therefore uses a long-context approach: the entire ICHI knowledge base is included in every prompt, ensuring Claude always has the full vocabulary and rules available – not just fragments.
This is why a single isolated request costs almost as much as the first request in a longer session: the large fixed "knowledge block" dominates the token count regardless of how short your actual question is.
Where costs do increase noticeably is when you ask many questions in quick succession in the same session, because each follow-up question also carries the growing conversation history alongside the ICHI data.
⚠️ Keep your API Key safe
Your API Key is like a password that authorises charges to your account.
- Never share it publicly or paste it into emails or chat messages.
- CodAs does not store or log your key anywhere.
- If you suspect your key has been compromised, go to console.anthropic.com and delete it immediately – then create a new one.
- You can set a monthly spending limit under Settings → Billing → Usage limits to protect yourself from unexpected costs.