LatentSift: Policy-State Filtering for Token-Efficient Verification of Software Engineering Agents
Verifying the many candidate trajectories a software engineering agent generates at test time can cost as many tokens as generating them. LatentSift replaces the LLM-based first verification stage with a token-free, execution-free filter over hidden states the policy already produced — reasoning, observation and function-call states compared against banks from successful and unsuccessful training trajectories. On SWE-bench Verified, hybrid Best@16 matches or improves on each agent's reference workflow.
