Getting an API key for the HR Buzz coach
Prices checked 27 October 2026 on each service's own pricing page. They change, so check the page for your service before you add credit.
The HR Buzz coach is optional. It needs an API key from one AI service. Paste the key into HR Buzz under Coach settings: the app recognises which service it belongs to, checks it, and picks a small, inexpensive model by itself. Coach settings then shows the service and model it chose.
Why a key and not a sign-in? A ChatGPT, Claude or Gemini subscription covers that company's own app. The API is billed separately, by use, and Anthropic does not allow other apps to sign in with a Claude account. For a coach that makes a handful of requests a day, an API key usually costs far less than a subscription.
What it costs
A typical day uses a morning plan, a debrief after your session and a couple of questions. Measured from the size of the app's own requests (about 60 sessions over 12 weeks, 9,000 to 13,000 input tokens per request), that is about 42,000 input and 11,500 output tokens a day: roughly 1.3 million input and 0.35 million output tokens a month. The model's reasoning counts as output.
| Service | Model HR Buzz picks | Price per 1M tokens (in / out) | About, per month |
|---|---|---|---|
| OpenAI (ChatGPT) | newest "luna" or "mini", e.g. gpt-6-luna |
$0.10 / $0.50 | $0.30 |
| Claude (Anthropic) | newest Haiku, e.g. claude-haiku-5-5 |
$0.10 / $0.50 | $0.30 |
| Gemini (Google) | newest Flash, e.g. gemini-3.8-flash |
$0.75 / $3.75 until 31 Dec 2026, then $1.50 / $7.50 | $2.20, then $4.50 |
| DeepSeek | deepseek-flash |
$0.15 / $0.60 off-peak, double at peak hours | $0.40 to $0.80 |
- DeepSeek's peak hours are 01:00 to 04:00 and 06:00 to 10:00 UTC, Monday to Friday; all other times are off-peak.
- Older small models cost more per token:
gpt-5-mini($0.25 / $2.00) is about $1.00 a month,gpt-5.4-mini($0.75 / $4.50) about $2.50. - The larger models, such as Claude Sonnet or OpenAI's "sol" tier, would cost about $6 a month at the same use. HR Buzz does not choose them.
- These are estimates. Chatting with the coach a lot raises them; a quiet week lowers them. Most services let you set a monthly spending limit: do that.
Official pricing pages: OpenAI · Claude · Gemini · DeepSeek
How to get a key
Each service shows a key once, when you create it: copy it straight away and paste it into HR Buzz. Treat it like a password.
OpenAI (ChatGPT)
- Open platform.openai.com/api-keys and sign in.
- Add a few dollars of credit under Billing.
- Choose Create new secret key, copy it.
Claude (Anthropic)
- Open platform.claude.com/settings/keys and sign in.
- Add a few dollars of credit under Billing.
- Choose Create key, copy it.
Gemini (Google)
- Open aistudio.google.com/apikey and sign in with a Google account.
- Choose Create API key, copy it.
- Turn on billing for the key's project before you use it for coaching. Google's pricing page says content sent on the free tier may be used to improve Google's products and that paid-tier content is not. The coach sends your training and health summary, so use the paid tier.
DeepSeek
- Open platform.deepseek.com/api_keys and sign in.
- Top up your balance.
- Choose Create new API key, copy it.
Then
- In HR Buzz open Coach, paste the key and leave the screen. HR Buzz checks it and shows "Using ..." with the service and model.
- If a key is wrong, HR Buzz says so and does not keep it. If you paste a key by mistake somewhere else, delete it on the service's page and create a new one.
- To switch service, paste a key from another one.
What is sent
Only when the coach is on, and only to the service your key belongs to: session totals, zones, splits, notes, resting-test results, check-ins, and your age, sex, weight and max heart rate. Never GPS, second-by-second heart rate, or your name. Chest-pain and similar symptoms are answered on the phone and never sent. The service's own terms and privacy policy apply to what it receives; read them before you turn the coach on. Full details are in the privacy policy.