BootstrapAgent: Turning Repository Setup into Reusable Agent Knowledge

Code agents are rapidly lowering the barrier for developers to work with unfamiliar repositories, and are increasingly adopted for tasks such as building prototypes, reproducing experiments, and adding features. Reliably executing these tasks depends on a critical prerequisite: the target repository must first be successfully set up and brought into a usable development state. This bootstrapping process requires substantial trial-and-error exploration by code agents, yet the resulting knowledge (e.g., resolved dependencies, repair strategies) remains trapped in a single conversation, unavailable to future agents or developers. We therefore formulate repository bootstrapping as a reusable startup knowledge problem and introduce BootstrapAgent, a multi-agent framework that distills bootstrap exploration into a persistent, verifiable, agent-consumable .bootstrap contract. Through CI evidence extraction, structured planning, deterministic Docker-based verification, and trace-driven repair, BootstrapAgent generates a contract covering environment setup, diagnostic checks, minimal verification, and accumulated repair knowledge. We further propose warm repair with clean replay to accelerate iterative debugging without sacrificing cold-start reproducibility, and a two-level verification strategy to prevent reward hacking. Experiments on three benchmarks show that BootstrapAgent achieves a 92.9% success rate, outperforming the baseline by over 10% while reducing downstream agent token usage by 25.9% and build time by 22.3%.