Bitsaga Signet
A private Bitcoin network we run ourselves, with blocks every thirty seconds and a faucet that always has coins. It exists for one job: to make the multisig tutorial inside our SeedSigner simulator work, with real confirmations and nothing at stake.
You cannot connect your own wallet to this network. The Electrum server a wallet would sync against listens on our own private network only, on purpose, and we are not planning to open it. This page explains what the network is. The thing you actually use is the simulator.
These are not real bitcoin. They exist only on our test network, cannot be sold or sent to anyone, and are worth nothing.
What a signet is
A signet is a Bitcoin network where a block only counts if it carries a signature matching a designated challenge script. Whoever holds the matching key decides what a block is. We generated our own challenge, so this is our own chain: our cadence, our faucet, always up, no reorgs, nothing shared with anybody else's test network.
Everything else behaves exactly like Bitcoin, because the software is Bitcoin: the same node, the same addresses, the same signatures, the same part-signed transactions moving between a wallet and a signing device. That is the point. A 2 of 3 multisig built here is the real procedure, not an animation of it.
Public test networks would have been the easier choice and a worse one. Blocks arrive when they feel like it, faucets run dry, and the chain sometimes reorganises under you. Ours produces a block every thirty seconds, so a confirmation lands while you are still looking at the screen, which is the difference between a tutorial someone finishes and one they abandon.
Not a public network
The piece a wallet actually talks to is an Electrum server, and ours listens on localhost and on our own private network, nowhere else. That is a decision, not an unfinished job. Holding a long-lived socket open to strangers on a box that also runs a mainnet node is an exposure we would be taking for a chain whose coins are worth nothing, and the simulator reaches the network from the inside, which is all it needs.
So there is nothing here to point a wallet at, and no setting we could hand you that would change it. The node's peer-to-peer port is closed to the outside for the same reason, so you cannot sync your own node against us either. What is public is exactly two things: the status readout above, and the faucet below.
Addresses here start with tb1, the same as Bitcoin's testnet. That
is not a mistake: signet deliberately shares testnet's address format and key derivation,
which is why the simulator is set to Testnet rather than to anything else, and why SeedSigner
has no signet option to look for.
The challenge above is the script every block on this network has to be signed against. It is what makes this a separate Bitcoin rather than a copy of one, and it is not a secret. The key that signs against it is, and it does not leave the box.
The faucet
This is the faucet the tutorial uses to fund the wallet you build in the simulator. It is public, so you can also drive it by hand: paste an address, get 0.01 test bitcoin, and it is in a block about thirty seconds later.
Worth being straight about what that gets you. The payment is real and it lands on the chain, but with no way to connect a wallet you have no way to watch it arrive. Inside the simulator you do, which is the whole reason the faucet exists.
Paste an address from the simulator and the faucet will send it coins.
Check it yourself
A page can claim to run a Bitcoin network by typing a number into it. This one hands you the actual bytes instead. Below, your browser takes the latest block off this chain and redoes the check Bitcoin Core does: it works out what was signed, finds the signature in the block, and confirms it was made by the key this network is named after. The arithmetic happens on your machine, in one file you can read, using no library and nothing we sent you except the block itself.
None of it makes these coins worth anything. They are worth nothing, and no amount of valid signature changes that. What it shows is that the blocks here are genuinely signed by the key this chain is named after, which is a different and much smaller claim.
The script every block here has to be signed against. Publishing it is the whole point: it is what makes this a separate Bitcoin rather than a copy of one. It does not let anyone in, because there is nothing public to connect to, and the key that satisfies it never leaves the box.
The four bytes every message between nodes on this chain begins with. Nodes throw away anything that starts with somebody else's. This page worked it out from the challenge above rather than being told it, which is why the two are tied together and not just printed next to each other.
The first block. Worth being straight about: this one is not ours. Bitcoin Core hard-codes a single genesis block for every signet, so the public signet and every custom one share it. It tells you this is a signet. It does not tell you which.
Fetching the latest block and checking its signature in your browser.
All of it comes from one read-only endpoint, which returns the block header, the coinbase transaction the signature lives in, and the merkle branch tying them together. Nothing else is needed, and nothing else is offered.
A check that cannot fail proves nothing. Change something and watch it notice:
What this does not settle. That the block is on a chain anyone else can see. We run the only node on this network and we hold the key that signs its blocks, so we could sign a block and show it to you without it being part of anything. Ruling that out needs a second, independent node, and this network deliberately has none. What the check does rule out is a made-up number: nobody without the key can produce a block that passes.
The same idea, one step further along. Paste the id of any transaction on this chain and your browser will check three things in a row: that the bytes really are that transaction, that they hash up a merkle path into a particular block header, and that the header carries this network's signature. Claim from the faucet above and the id lands in this box by itself.
Nothing to hand?
Same again: it has to be able to fail.
What this does not settle. The same thing as above, plus one more: a confirmation on this chain is a confirmation on this chain. It is not a payment, the coins are worth nothing, and nobody outside can see any of it.
The tutorial
Multisig is the thing people nod along to and then never set up, because the first attempt is the frightening one and nobody wants to make it with real coins. The SeedSigner simulator walks you through one: three seeds on three cards, a 2 of 3 wallet built from their public keys, coins from the faucet, then a spend signed twice and broadcast. This network is what makes that end in a confirmation instead of a shrug.
The walkthrough lives in the simulator, not here. It is a signing device you drive in your browser, and the tutorial runs alongside it. Use a throwaway seed there, never one that holds real money.
Honest notes
These are not real bitcoin. They exist only on our test network, cannot be sold or sent to anyone, and are worth nothing. Nobody can sell them to you, and if anyone offers to buy them from you, that is the whole scam.
It is not a network you can join. The Electrum server is private to us and the peer-to-peer port is closed, so no outside wallet and no outside node can sync against this chain. That is settled, not a gap waiting to be filled.
The network can be reset. It is a teaching tool, not a service. If we ever have to start it again, everything on it disappears. Do not put anything here you would miss.
Use throwaway seeds. Never type a seed that holds real money into anything, including this. The simulator runs in a browser tab, which is exactly the sort of place a real seed should never be, and no part of it is built to protect one.
The tutorial holds all three keys on one device. That is fine for learning and wrong for real money, where the entire point of multisig is that the keys live in different places, and often in different hands.
When you want the real thing, the same flow runs on real hardware holding real keys, and that is the setup we build with people. Talk to us.