RL for Agents

Reinforcement learning for agentic behaviour

22 articles

RL for Agents

Distillation Before Reinforcement Learning Improves Reasoning Model Post-Training

Li and colleagues compare ways to combine on-policy distillation (OPD), which supplies dense teacher feedback at the token level, with reinforcement learning from verifiable rewards (RLVR), which uses sparse outcome-based signals. Across logic and mathematics benchmarks, they find that completing OPD before switching to RLVR works consistently better than pure OPD, pure RLVR, or joint optimization.

5 Sept 2026
RL for Agents

Sparse verifier feedback makes broad credit assignment outperform turn targeting

Zhou et al. study how reinforcement-learning credit should be distributed across multi-turn agent trajectories when only the final outcome is verified. They find that the decisive factor is verifier information density—the share of prerequisite steps whose correctness is observable—and that broad coverage outperforms targeted credit in the low-information regime typical of terminal-state evaluation.

4 Sept 2026
RL for Agents

Privileged supervision improves action-level credit for language-model agents

Yang et al. address a credit-assignment problem in reinforcement learning for agents: a verified task outcome is typically applied uniformly to every decision in a long interaction. Their TASPO method uses privileged information from successful experiences to weight individual actions, improving performance over GRPO by 10.6% across three agentic benchmarks and transferring better to unseen tasks.

2 Sept 2026
RL for Agents

Paper-derived rubrics improve AI generation of scientific research plans

The authors turn 20,000 scientific papers into training environments for research-plan generation, deriving prompts from each paper’s goals and background while extracting evaluation criteria from its methods and experiments. Across three Qwen3 model sizes, their rubric-centered training schedule produced higher benchmark scores than supervised fine-tuning, either training stage alone, or the same stages in reverse order.

2 Sept 2026
RL for Agents

Shared-prefix training accelerates reinforcement learning for hybrid-attention agents

Meng et al. introduce HARTS, a training system that compresses shared prefixes in agentic reinforcement-learning rollout trees and schedules the remaining work across microbatches and data-parallel replicas. On rollouts generated from SWE-bench tasks, it delivered 4.81–4.87× speedups for forward, backward, and gradient computation while maintaining numerical and early-training behavior close to trajectory-wise training.

1 Sept 2026
RL for Agents

Contrastive branch training improves credit assignment for tool-using language models

Wang et al. introduce Contrastive Branch Policy Optimization (CBPO), a reinforcement-learning method that separates where to sample alternative continuations from how to assign credit to tokens. Across ten mathematical-reasoning and knowledge-search benchmarks, the authors report the highest macro-average accuracy among the evaluated policy-optimization and branch-based methods at two model scales.

27 Aug 2026
RL for Agents

New framework lets you train AI agents inside the same harness systems they use at inference

The authors present OpenForgeRL, an open-source framework that trains stateful, harness-based AI agents end-to-end using standard reinforcement learning libraries. It wraps the harness's model calls via a proxy for data recording and orchestrates rollouts in remote Kubernetes containers, yielding competitive results on tool-use, browser, and computer-use benchmarks with relatively few training tasks.

24 July 2026
RL for Agents

Dense credit assignment from gold-answer log-probabilities improves long-horizon agent RL

The authors propose TRACE, a credit-assignment method for long-horizon agentic RL that derives per-action rewards from the log-probability of the gold answer under a frozen reference model, using temporal-difference learning. On the closed-web BrowseComp-Plus benchmark, TRACE raises Qwen3-4B from 7.2 to 35.6 and Qwen3-30B-A3B from 8.4 to 42.6, and enables pure RL training without cold-start supervised fine-tuning or live-web data.

16 July 2026