Source note

CodeRescue: Budget-Calibrated Recovery Routing for Coding Agents

Coding AgentsCost Aware RoutingTest Time RecoveryConformal CalibrationSoftware Engineering

CodeRescue routes a failed coding-agent attempt to reflect, replan, or escalate, balancing solve rate against recovery cost. A supervised router plus conformal calibration supports multiple deployment budgets without retraining.

  • After a cheap coding model fails, systems often escalate immediately, although execution feedback may enable a cheaper repair or fresh attempt.
  • The problem matters because coding-agent recovery actions have different costs and non-monotone success patterns, so a fixed action or binary cascade cannot reliably optimize quality under changing budgets.
  • A cheap model first attempts each programming task. For failures, a router observes the problem, execution verdict, and stderr trace, then selects reflect (repair with feedback), replan (generate a fresh cheap solution), or escalate (use a stronger model).
  • The router is a fine-tuned Qwen3.5-4B model trained on execution rollouts, with each example labeled by its cheapest successful recovery action.
  • It scores actions with normalized label probabilities and chooses the action maximizing router score minus a cost penalty: s(a|x) - λc(a,x).
  • A Conformal Risk Control layer selects λ for a user-specified mean-cost budget from a calibration split, allowing budget changes through table lookup rather than router retraining. Its guarantee is marginal expected-cost control under exchangeability, not solve-rate control.
  • Across APPS, TACO, BigCodeBench, LiveCodeBench, and CodeContests, the study attempted approximately 27,300 problems; the training split contained 4,656 examples, with 360 calibration and 360 test problems.
  • The fine-tuned router achieved 0.817 solve rate at 5.51 m**meanrecoverycost,comparedwith**0.686/7.22m** mean recovery cost, compared with **0.686 / 7.22 m for always-escalate, 0.453 / 1.59 m**foralwaysreplan,and**0.275/1.24m** for always-replan, and **0.275 / 1.24 m for always-reflect.
  • The abstract reports that, in the main GPT-5.4-nano/GPT-5.4 setting, one CRC-calibrated frontier point exceeded always-escalate's solve rate while using 35% of its mean recovery cost.
  • The experiments show complementary success patterns for cheap recovery and escalation, supporting a discrete cost-quality frontier rather than a uniformly ordered recovery ladder.
  • The formal CRC result guarantees expected recovery cost at or below the requested budget under its exchangeability, bounded-cost, and feasibility assumptions; empirical solve-rate changes remain dataset- and router-dependent.