Bonsai
What we actually removed
A promise about carbon is worth what its receipts are worth. Bonsai buys removal for the carbon it burns, and every invoice goes here — with what we emitted, what we owed, and what we bought.
The three numbers
Each entry below carries the same three, and they are not the same thing:
- EmittedWhat Bonsai's infrastructure cost the atmosphere that month, from real token usage on each model. How a token becomes a gram is set out in full at Impact & methodology.
- CommittedWhat we owed on it. 2× the emissions of free-plan usage and 10× of Pro usage, added up across everyone — so the figure moves with the mix of plans, not just with the total.
- RemovedWhat the invoice actually bought. This is the only one of the three with a receipt behind it, and the only one that has left our bank account.
September 2026
The first month with donations in it.
Two debts settled on one invoice. The first is the usual one: 1,562 prompts from 17 people, 1,559.9 g of emissions, and 14.70 kg owed on them under the plan multipliers. The second is new: 20% of every donation is promised to carbon removal, and September's share bought 70 kg. Rounding the total up to whole units leaves 5.30 kg more removed than we owed.
| Owed for | Emitted | Committed |
|---|---|---|
| Usage, September 2026 | 1,559.9129 g | 14,699.9868 g |
| Donations, 20% share | — | 70,000.0000 g |
| Both | 1,559.9129 g | 84,699.9868 g |
| The receipt | |
|---|---|
| Supplier | Climeworks AG, Zurich |
| Bought | Nature and Technology — 90 units × 1 kg |
| Paid | $22.50 USD, 1 October 2026 |
| Order confirmation | 2026-10-01-393460 |
| Invoice | 2026-10-01-climeworks.pdf (redacted) |
The same portfolio as before, bought the same way. The invoice is published with the billing name, the customer id and the card details removed; every figure on it is untouched.
July – August 2026
Our first. One purchase, covering both months.
Two months on one invoice, so here they are apart as well as together. Removal is sold by the kilogram and the debt came to 8.807 of them; buying the tenth rather than stopping at nine leaves 1.19 kg more removed than we owed.
| Month | Emitted | Committed |
|---|---|---|
| July 2026 | 151.5765 g | 4,720.0000 g |
| August 2026 | 454.7403 g | 4,086.9906 g |
| Both | 606.3168 g | 8,806.9906 g |
| The receipt | |
|---|---|
| Supplier | Climeworks AG, Zurich |
| Bought | Nature and Technology — 10 units × 1 kg |
| Paid | $2.50 USD, 1 September 2026 |
| Order confirmation | 2026-09-01-389972 |
| Invoice | 2026-07-08-climeworks.pdf (redacted) |
Bought through Climeworks' Nature and Technology portfolio — carbon taken back out of the air, rather than emissions avoided somewhere else and counted as a saving. The invoice is published with the billing name, the customer id and the card details removed; every figure on it is untouched, and the order number is enough for Climeworks to confirm it.
What this page is not
It is a record of purchases, not a certification. Nobody audits it but us, and the emitted figure it starts from is a model — a model we publish in full, uncertainty included, precisely so that it can be argued with. The removal is the part that is beyond argument: it was bought, and the invoice is here.
If a number here looks wrong, we would rather hear it than not: support@bonsaiedu.org.