Breakpoints are handled in an asynchronous debug model by building a queue of basic operations to run a debug application program interface (API). User commands are each broken down into a simple command and placed on the queue. In response to a debug event, a new simple command is generated. If, when a first command on the queue is processed, a thread is not stopped at a location with an installed breakpoint, an operation corresponding to the first command is started, the operation is removed from the queue, and a next operation is started. If the thread is stopped at the location with the breakpoint, the thread performs a hop. When the hop terminates, the first command is removed from the queue. If the first command is a run command, and there is no cause to stop the thread, the run command is moved to the end of the queue.