> ## Documentation Index
> Fetch the complete documentation index at: https://docs.geckovision.tech/llms.txt
> Use this file to discover all available pages before exploring further.
# A real transaction
> An agent bought a bottle of water for 0.1 USDC on Solana mainnet. Gecko verified the call before it was signed — and the chain agreed.
Every other page here ends at a simulation. This one ends on chain — and the point is
simple enough to say in one line: **before the money moved, Gecko said exactly what would
happen, and that is exactly what happened.**
On 2026-08-06 an agentic wallet bought a bottle of water at a bar that takes crypto —
0.1 USDC, Solana mainnet, a real store, a real product. Before it was signed, Gecko
planned the call, simulated it against live mainnet, and bound the receipt to the exact
message. Then a wallet signed it and it landed.
## Check it yourself
[**Open this transaction on Solscan
↗**](https://solscan.io/tx/5cjBs5VE8WVVctG2EoUkYiRkW92sXkoT4YsNxszWC9CE3sK7triTJ5vnY6TrcQ2BRPYUtWsd3LtTnyieUfn8Hw2Y)
```
5cjBs5VE8WVVctG2EoUkYiRkW92sXkoT4YsNxszWC9CE3sK7triTJ5vnY6TrcQ2BRPYUtWsd3LtTnyieUfn8Hw2Y
```
| | |
| ----------- | ----------------------------------------------------------------- |
| what moved | 10 cents — buyer −0.1 USDC, bar +0.1 USDC |
| did it work | yes, no error |
| slot | 437633643 |
| compute | 36,508 units — the network's measure of work, matched to the unit |
Nothing on this page requires taking our word for it. Open the link, or ask a node
directly:
```bash theme={null}
curl -s https://api.mainnet-beta.solana.com -X POST \
-H 'content-type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"getTransaction","params":
["5cjBs5VE8WVVctG2EoUkYiRkW92sXkoT4YsNxszWC9CE3sK7triTJ5vnY6TrcQ2BRPYUtWsd3LtTnyieUfn8Hw2Y",
{"maxSupportedTransactionVersion":0}]}' | jq '.result.meta.computeUnitsConsumed'
```
## Then we did it ten more times
One exact match can be luck. On 7 August 2026 the same agent bought ten more bottles,
0.1 USDC each, each one planned and simulated against live mainnet before it was signed.
**Every receipt predicted 36,399 compute units. The chain charged 36,399. Ten times out
of ten.**
| # | transaction | slot | consumed |
| -- | --------------------------------------------------------------------------------------------------------------------------------- | --------- | -------- |
| 1 | [`4yBoPqPc…srsv`](https://solscan.io/tx/4yBoPqPc6YqPQjEeC7RGXtgCH9XG9zyx7CXYQ4WdTijbrLWDvE8Yo4eKFU4JAannDtcZJY4BdJN9J1J6mnmrsrsv) | 437721653 | 36,399 |
| 2 | [`3GvCjqxu…wi5R`](https://solscan.io/tx/3GvCjqxuy5KBuyLRL4f9SKpJrETMNhM6FP4fXBpTzzQJVDW6tXvpfAovy4zFn3j4fSMh2VeJ8VAdxWVuak5Jwi5R) | 437721889 | 36,399 |
| 3 | [`3MM7QMLz…cHwb`](https://solscan.io/tx/3MM7QMLzpoZNcN2JSnBcSxDiWeDWJgbMHe7pHNcGfw6EAKXLTz5kEuAwg6pbxCnVgTzjBFfcEFFo1BQs2RVGcHwb) | 437722129 | 36,399 |
| 4 | [`zXsDSEQt…F5C8`](https://solscan.io/tx/zXsDSEQtZt24FkT4eeNpiu4aCB1HXUKPKCeEG291CdHPj6NnfhZzu1zkvvunrCBu7ei2uhoRtmytMDMD9kXF5C8) | 437722295 | 36,399 |
| 5 | [`o6Da6NZQ…FSi9`](https://solscan.io/tx/o6Da6NZQe4DFag8VNEGHqCY3zuYocfdWT7n7Z7tqNbAJFBg69pNsCSiN51HeDuouW6T6XQeHicVZaWrpsdRFSi9) | 437722451 | 36,399 |
| 6 | [`3VrHHuzi…Di2u`](https://solscan.io/tx/3VrHHuzi2gC5QjnXBdWRAb5nhDkEPowVuZBnMNCqac8Ty2NeuykAQm7GA44qXfUt5TzCL5yQH4Ussi6nvKqpDi2u) | 437722629 | 36,399 |
| 7 | [`4QBnD6Yc…8iRj`](https://solscan.io/tx/4QBnD6Yc6sGYzeCVmbi9CpJoZdRfjBEtwMRt8XWVdjpeXwBrM2ApQmHKUACTvX2t3FNxyDqErZNDTY3ifuwE8iRj) | 437722762 | 36,399 |
| 8 | [`2NBodoD8…5a1B`](https://solscan.io/tx/2NBodoD8VNg1wqUXaxNQJUKTpZ9gkmM445d9NZFXLygaYuxtDyDQsH2MSp8Mdd3BYHci9Q6EPMaCJBGBQWaP5a1B) | 437722902 | 36,399 |
| 9 | [`33NkTQ5u…WLW1`](https://solscan.io/tx/33NkTQ5uJL85AtpsLMbWJu9L1PT9dKA4jEm5bFW9b2TpKcP7pb3br2up1KiZWmrzBzyPHvWS98rEwpKv7ac3WLW1) | 437722993 | 36,399 |
| 10 | [`3i92aBEY…AMrs`](https://solscan.io/tx/3i92aBEYsbHBotKcpaB8SxWDWEULp2SuQcqyeShY8sDCzFWQq4MLaN6URreG4QdBF3qRGR3eSYpqQR72kD2wAMrs) | 437723077 | 36,399 |
The books balance to the unit: 1.0 USDC spent, and exactly 50,000 lamports of fees —
ten transactions at Solana's 5,000-lamport base fee.
**36,399, not 36,508.** The first purchase wrote a record into the store's account, so
the program does slightly different work now. Both numbers are correct for the state they
were measured against — which is the whole point, and why a receipt is taken at the moment
you sign rather than the day before.
## Then the agent did it without us
Every transaction above was signed by a key on a laptop. On 12 August 2026 that stopped
being true.
**The key moved into a hardware enclave and never came back.** Gecko asked a Privy server
wallet to sign; the private key has never existed on the machine that planned the
transaction, and nothing in Gecko can acquire one. The whole path — comprehend, plan,
simulate, bind, check the spend policy, sign, broadcast — ran in **one call, with no human
in the loop.**
| # | transaction | slot | consumed | signed by |
| -- | --------------------------------------------------------------------------------------------------------------------------------- | --------- | ---------- | ---------- |
| 12 | [`3kcngvKS…W5wR`](https://solscan.io/tx/3kcngvKSkfRze7UPc6v1MeeZvxZAR6VG8evoyoA2VGF1eG9MKGzg41838BCGRHqqQBDwQ4FpC8R6qSa18FRTW5wR) | 438850988 | 36,399 | an enclave |
| 13 | [`zqSHUEoT…fT6p`](https://solscan.io/tx/zqSHUEoTAD9W7KdNHV6bRZfXr6qzAjdqu2LNYfMarvg1JciDgwsNHU4WH7G273Keua6beEV76aDku7JiS3sfT6p) | 438887385 | 36,399 | an enclave |
| 14 | [`5FLvBcQw…u8UQ`](https://solscan.io/tx/5FLvBcQweiGDNuXxJ3VDxsvwzkyXB6YJame2fB4C6yWCfDMsyEskvuZNxTkspK7aDk5h8y7x8GkSp7sfpHw8u8UQ) | 438888470 | **22,527** | an enclave |
| 15 | [`4zhgdny6…oLi1`](https://solscan.io/tx/4zhgdny6Wh93XJ9M8hFBsky7oEVAWyv5ddg4h68XzHX2GnDr2c8zQnL4WyUXYVJ3LnS7TyWqEfv55M62bLgDoLi1) | 438920685 | 36,399 | an enclave |
| 16 | [`Hp77fgHF…dTX`](https://solscan.io/tx/Hp77fgHF85BduE3YiSPfCMYzBFercmiz66Sjh2F9DuNKx7fy9Z9jFEo4W6D9nj7xBE5QShKy9Gs7HBXCj6dxdTX) | 438937647 | 36,399 | an enclave |
**Sixteen transactions. Sixteen exact predictions.**
**#14 is the interesting one: 22,527 CU, not 36,399 — and predicted exactly anyway.** It
bought from a *different* storefront (`geckocoffee`), one that was not on any wired list.
The agent derived the store's address from its name, read the store's own account off the
chain, decoded the merchant and the menu out of it — Espresso, 0.1 USDC — and walked the
same verify-then-sign path. Different store, different account state, different work,
different number. The receipt predicted that number to the unit, which is the property
this page exists to demonstrate: the prediction tracks the *state*, not a memorised
constant.
**The first attempt was refused, and by the right party.** The enclave's own policy engine
rejected it: `policy_violation`. Wallet policies there are deny-by-default *per method*,
and the policy attached to that wallet only described a method we deliberately do not
use — the one that signs **and broadcasts** in a single step. Gecko asks for a signature
and submits the bytes itself, so that the signed message can be re-checked against the
receipt *before* anything reaches the chain. A vendor that broadcasts for you turns that
check into a post-mortem.
Fixing it meant adding a rule for the method we do use, restricted to the exact programs
this purchase touches. Which means the program allowlist now exists **on both sides**: in
Gecko, and inside the enclave, where we cannot switch it off either.
**What this shows:** one instruction, predicted exactly, sixteen times across three days,
two storefronts and several account states — the last five with no key on the planning
machine.
**What it does not show:** breadth. This is one program. [The program
surface](/program-surface) is where that claim is made and measured separately.
**And one thing it does not show that we would rather say out loud:** three of the four
spending caps in that run are real controls, but the rolling velocity counter is a file
the same process can write. A compromised agent could reset its own budget. Moving those
caps into the enclave — where the program allowlist already lives — is the next piece of
work, not a finished one.
## Three things had to agree
Gecko answered **will this work** — simulated, bound, PASS. The wallet answered **who
signs it**. The wallet's policy answered **are you allowed to spend this** — a single-
transaction limit, enforced independently.
Those are different guarantees, and none substitutes for another. A policy that approves
your spending limit cannot tell you the transaction reverts; a simulation that says it
lands cannot tell you whether you were allowed to make it.
**Gecko held no key and broadcast nothing.** It never does.
## The part that didn't go to plan
The video re-runs the pre-flight live, and the numbers don't match:
```
the chain charged 36,508 CU
a pre-flight NOW 36,399 CU
```
109 units apart — because *this very purchase* wrote a record into the store's receipts
account, so the program does slightly different work now.
That's not a defect, and hiding it would have cost the more useful lesson:
**A receipt is true for the state it was taken against.** Take it at the moment you sign
— not the day before. It's the same reason a receipt's strongest binding expires with its
blockhash, about a minute.
For the record, the pre-flight run immediately *before* the send did predict 36,508
exactly. We don't show that on camera, because it can't be re-derived now that the state
has moved — and a demo that can't reproduce its own claim shouldn't make it.
## Do it yourself
The same pre-flight runs against any wired program:
```bash theme={null}
npx @geckovision/gecko prove "route a swap out of hyUSD" \
--bind input_mint=… --bind output_mint=… --bind amount=… --bind user=…
```
You get the call it chose, what it rejected, every account with where it came from, and a
receipt — before anything is signed or spent.
Status, compute units, categorical failure class — and what it does not claim.
Seed recovery, provenance per account, and the gaps we flag instead of guessing.