# Intended User Actions

### Issuer

Issuers primarily interface with Auctioneers to create markets. If they choose to use a Callback contract, it must be deployed before creating a market. After the market is created, it will need to be whitelisted on the Callback. The same Callback can be used for multiple markets across multiple Auctioneers. 

Issuers can end markets at any time on the Auctioneer and set certain variables for a market after creation, such as `tuneInterval`, `tuneAdjustmentDelay`, and `debtDecayInterval`. 

However it is not recommended to change these unless the Issuer is experienced and knowledgeable about how it will impact the market operation. <mark style="color:red;">If in doubt, please reach out to Bond Protocol team.</mark>

<figure><img src="https://content.gitbook.com/content/RLNHGppzWLIBhbHOvrRS/blobs/bJpoSymux0oOsYyEUC2C/BP_Smart_Contracts-UserActions%20(1).svg" alt=""><figcaption></figcaption></figure>

### End user

End users primarily interact with the Aggregator to get market information and the Teller to purchase and redeem bonds.&#x20;

The following diagram shows the main actions expected from end users:

<figure><img src="https://content.gitbook.com/content/RLNHGppzWLIBhbHOvrRS/blobs/JH1JqHRXmg1chpYZ9ya7/BP_Smart_Contracts-UserActions.svg" alt=""><figcaption></figcaption></figure>