Buy on the marketplace
Reserve, prepare, sign, and broadcast, with the checks that stop you paying for something that already moved.
Universe implementation Verified 2026-08-31
Describes what a Bitcoin Universe service actually does today. It is not a statement about the protocol in general.
- Page ID
-
guides/buy-on-marketplace - Normative authority
- Universe implementation documentation
- Networks
- mainnet
- Documentation version
- 2026.08
- Audience
- everyone, holder, integrator
- Owner
- bitcoin-universe-docs
- Sources
-
- Universe ARC-20 index and Marketplace v1 authority
at
670030e50071private repository - Ordex marketplace contract
at
2f7d8d3ec59f
- Universe ARC-20 index and Marketplace v1 authority
at
- Known limitations
-
- Action gates default to off. Buy execution additionally requires an exact fee script to be configured on the deployment.
Before you start
Section titled “Before you start”- Supported networks: mainnet.
- Status: Universe implementation.
- Your funding inputs must be confirmed and uncoloured. Spending a coloured output to fund a purchase loses those units.
The lifecycle
Section titled “The lifecycle”- Read the listing. Record the Atomical ID, the price, and the exact payment script.
- Reserve. A reservation holds the listing while you prepare. Read the reservation back.
- Prepare the purchase. The service builds the settlement transaction and returns what you must sign.
- Sign. With the exact scope the prepare step specifies.
- Validate signed. The service checks your signed material against the blueprint before anything is broadcast.
- Broadcast. Only after validation passes.
- Verify settlement. See verify settlement.
What is validated before broadcast
Section titled “What is validated before broadcast”- The seller still controls the asset, at a stable checkpoint.
- Your funding inputs are confirmed, uncoloured in both the script hash view and location history, and of a supported type.
- The Atomicals blueprint assigns the selected asset cleanly to the buyer output, with no operation, no mixed Atomical ID, and no burn.
- Heights and hashes on both sides are unchanged across the bracket.
Anything else fails closed.
Check before signing
Section titled “Check before signing”| Check | Why |
|---|---|
| The Atomical ID matches the listing | A ticker or name is not identity |
| The price is exactly what you agreed | Including any disclosed marketplace fee |
| Your funding inputs are cardinal | Or you spend an asset to buy one |
| Every output is visible with script and value | You cannot verify what you cannot see |
| The signature scope | It must not let outputs change after you sign |
If it fails
Section titled “If it fails”| Failure | Meaning |
|---|---|
| Reservation expired | Reserve again. The listing may be gone |
| Stale ownership | The seller moved the asset. Nothing was spent |
| Mixed collateral | The seller’s output carries more than the asset |
| Checkpoint drift | The chain moved mid-check. Retry |
| Validation failed | Do not broadcast. Start again |
A failure before broadcast costs nothing.
The price, the settlement transaction fee, and any disclosed marketplace fee. The flow must show the breakdown before your final confirmation.