Train the Agent Before the Sandbox Exists
TL;DR for operators A team can have stable API contracts before it has an executable sandbox, populated user state, and reliable integration infrastructure. The usual assumption is that serious multi-step agent training must wait, because later API responses need to reflect what earlier calls changed. ESAT challenges that sequencing. Lee et al. generate stateful training trajectories from API specifications without the target environment, then validate and filter the interactions before training.1 On AppWorld, training with ESAT-S52 trajectories generated from 52 synthetic applications independent of AppWorld improves Task Goal Completion by 8.4 to 47.0 percentage points across evaluated models and usually outperforms training on trajectories collected inside the real AppWorld environment. ...