# Entities

The DAppControl contract may define which entities are permitted to act as the Bundler.  The frontend can designate one or more of the following:

1. DAppProxy: A specific address (or addresses) is permitted to bundle operations.
2. User: The User is permitted to bundle operations.
3. Builder: The builder ("block.coinbase") is permitted to bundle operations.
4. Solver: The top-bidding Solver is permitted to bundle the User Operation and their own Solver Operation, but may not include the Operations of other Solvers. 
5. Conditional: A specific function handles complex Bundler designation logic.
6. Time Limit: For On Chain auctions, any party may trigger the On Chain Bundler to execute the finalized transaction, pursuant to the passing of a minimum auction duration (as specified by the DApp.) 

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