How Circuit
works.
How blocks fit together and run, where a coin's money lives, how every run is proven on Solana, and what happens when you launch. A coin's program runs on Circuit's servers; its rules and receipts are fingerprinted on Solana, and its money sits in a vault that nobody owns, so holders don't have to take anyone's word for it.
How a block works.
A Circuit program is a stack of blocks. Each block does one small thing, and blocks snap together top to bottom like a recipe. There is no code underneath to edit: the blocks are the program.
What happens on a run.
A run starts when the Event at the top of a stack happens. Circuit then walks down the stack, one block at a time.
Block categories.
Every block belongs to one category. The color and the two-letter tag tell you which.
The coin's vault.
Every coin gets its own vault when it launches: a smart wallet on Solana. The coin's creator fees go straight into it. Nobody owns it, not the creator and not Circuit. Circuit's server can only run the coin's published rules inside the limits, and can never change them.
How fees are collected.
You do not claim anything by hand. Collecting is automatic.
The money blocks.
These blocks are pretend in the builder and real on a launched coin. A coin's vault can only buy, sell, burn and send its own coin and SOL.
There is no block that sends the vault's money to a new owner, and none that can pay for something outside the coin. Buy back means the Buy block pointed at the coin's own address.
Limits.
A coin never spends more than it has earned: it can only use what is in its vault. On top of that, each run, each hour and each day have a cap, and the caps scale with the fees the coin has earned, so a small coin spends small and a busy coin can spend more. Swaps accept at most 3% slippage, and one airdrop pays at most 50 holders. The limits are shown before you sign and are locked with the rules.
What Circuit charges.
Circuit's cut comes out of the coin's real fee split, which the launch screen shows under “Where creator fees go” before you sign. That split is locked on Solana at launch, so it cannot change later. Any launch fee is shown on the same screen. If a number is not on that screen before you sign, it does not apply to your coin.
If Circuit's servers are down.
The coin's rules pause. Nothing runs and nothing is spent. The money stays in the vault, where no one can take it, and fees keep arriving for it. The coin itself keeps trading on pump.fun because it never depended on Circuit to exist.
Every run leaves a receipt.
A receipt has three parts. At the top is what caused the run: the trade, the wallet, and the transaction on Solscan. In the middle are the steps the program took, in order, with the values it used. At the bottom are the program's fingerprint, the receipt's fingerprint, and the Solana transaction it was written in.
Here is one run from start to finish: a real trade arrives, the rule it matches lights up, the effects appear, and the receipt settles and is written to Solana.
@..@ (----) ( >__< )
Check a receipt yourself.
Each receipt is turned into a short fingerprint (a SHA-256 hash). Every few minutes Circuit collects the new fingerprints into a batch and writes the batch's root to Solana in a single transaction. Pressing Verify recomputes the fingerprint in your browser, fetches that transaction, and checks the receipt is part of the batch.
A receipt shows “anchoring in the next batch” until its batch is written, usually within 3 minutes.
The rules can never change.
You design your blocks once, then launch. The launch transaction creates the coin and writes the program's fingerprint to Solana from your wallet. There is no edit button after that: not for you, not for Circuit. The coin's page shows the fingerprint and the transaction it was written in.
Rules holders can read.
Circuit writes the program out as sentences, straight from the blocks. Creators can't edit the text, so it always matches what runs. Every coin page shows it at the top.
From blocks to a live coin.
The coin pays for its own AI.
AI blocks (names, personalities, posts, decisions) cost a fraction of a cent each time they run. Circuit charges the coin a markup on what the model costs; the launch window shows the exact price per call before you sign. A program with AI blocks starts with an AI starter credit paid in the launch transaction, so AI works from the first trade; a program with no AI blocks pays nothing extra. The starter sits in the coin's vault and can only be spent on AI, and no rule can ever spend AI money. After the starter, AI is paid from the coin's own fees. If a coin has neither, AI blocks are skipped and the receipt says "AI skipped: this coin has no AI credit yet" (nothing is invented). Nothing else stops. The meter below calls it fuel.
One page per coin.
Every live coin gets circuitdev.fun/p/your-coin. The identity, rules, proof and activity always sit in the same place. The page also shows its state honestly: waiting for the first trade, AI paused, or stopped by an error. Trades appear on it within seconds, and the vault's address is shown so you can look it up on Solana.
Build yours in the builder →Questions and answers.
Who owns the coin's vault?
Nobody. Not the creator and not Circuit. Its only job is to run the coin's published rules, and it can do nothing else.
Can the creator take the fees?
Only if the rules say so, for example a block that sends part of each fee to the creator's wallet. That rule is shown before launch and can never be changed.
Can the rules change after launch?
No. They are locked at launch and their fingerprint is written to Solana. Not the creator and not Circuit can edit them.
What does it cost to launch?
The launch screen shows everything before you sign: the network fee, the small amount sent to the vault for setup, and where the creator fees go. Nothing is hidden behind the signature.
What does Circuit take?
Whatever Circuit's cut is, it is part of the fee split shown on the launch screen and locked on Solana at launch. It cannot grow afterwards.
When do the rules run?
Trades show on the coin page within seconds. Timers run once a minute at the finest. Fee rules run after the fees are collected.
What if the coin has no fees yet?
Then there is nothing to spend. A money block that cannot be paid stops that run, and the receipt says why.
Can a coin spend more than it earned?
No. It can only spend what is in its vault, and the limits on each run, hour and day grow only as the coin earns.
What happens to AI when the AI credit is gone?
AI blocks are paid from the coin's own fees. A coin with no AI credit skips AI and uses simple fallbacks, such as default names. Everything else keeps running.
Is the builder using real money?
No. In the builder every money block is pretend, so you can test freely. After launch the same blocks are real.
How can a holder check what a coin really does?
Read the plain-English rules on the coin page, look at the receipts, and press Verify to check a receipt against Solana yourself.