draften pays for language models through the organisation's or the operator's API keys. Here is what the cost is made of and how to keep an eye on it.
What the cost is made of
| Task | Model (default) | Roughly |
|---|---|---|
| triage of new mail | Claude Haiku 4.5 | about 0.005 USD per check, under 1 USD a month |
| writing a draft | Claude Sonnet 5 | 0.05–0.20 USD per draft |
| writing a draft (Opus 5) | Claude Opus 5 | 0.12–0.27 USD per draft |
| learning (evaluation, lessons) | Claude Haiku 4.5 | little — a cheap model, one call per evaluated draft |
| the new-assistant wizard | Haiku + Sonnet | a few USD once, an estimate before every step |
| the trial set | as writing | per message run |
At 3–5 drafts a day, a mailbox on Sonnet 5 comes to roughly 10–20 USD a month. Prices are in USD as the provider charges them; draften does not convert them. A local model counts as free.
Prices per million tokens (checked on 6 and 15 September 2026): Haiku 4.5 1 / 5 USD (input / output), Sonnet 5 2 / 10 USD, Opus 5 5 / 25 USD; a cache read costs 0.1 times the input.
Where you see the cost
- The assistant's Overview — the What the models cost card for the period, today's spend and the cap.
- Mail and Drafts — the cost of every message and draft.
- The assistant's Settings → Activity — requests and mail checks.
- At the model provider — invoices and account limits.
The assistant's daily cap
The assistant's Settings → Behaviour and limits → Daily cost cap (USD). Once reached, the assistant that day:
- writes no drafts, does no triage, evaluation or learning,
- starts no paid wizard step, trial or on-request processing (work under way finishes),
- only keeps following earlier drafts (which costs nothing).
The day follows the organisation's time zone. The Overview then shows a warning and new mail gets the limit status.
The default is no cap — we recommend setting one for every assistant.
Draft count limits
Besides money, counts keep the assistant in check (defaults):
| Limit | Default |
|---|---|
| Drafts per day | 60 |
| Drafts per sender per day | 5 |
| Drafts per mail check | 15 |
The per-sender limit guards against a loop of two machines; the per-check limit spreads a flood of mail over further checks.
A limit at the provider
The most reliable safeguard is a monthly spend limit right at the model provider. When the account reaches it, the provider refuses further calls; messages get the failed status after three unsuccessful attempts.