AI Coding Live News

Terminal-RSI: Recursive Self-Improving Terminal Agents via Trajectory Self-Rewrite and Critic-Inheriting Policy Refinement Hit 86.52% on Terminal-Bench 2.1

Terminal agents frequently struggle to convert partial command-line progress into complete end-to-end task resolution. Researchers from Tencent AI Lab and NUS introduce Terminal-RSI, alternating Recursive Self-Rewrite (RSR) of verified trajectories with critic-inheriting Recursive Policy-Refine (RPR) alongside Turn-Boundary Skip-Observation GAE (TB-GAE). Evolving Qwen3.8-27B across five stages yields Terminal-RSI-27B, achieving 86.52% on Terminal-Bench 2.1 and 79.00% on Terminal-Bench Hard.

Terminal-RSI: Recursive Self-Improving Terminal Agents via Trajectory Self-Rewrite and Critic-Inheriting Policy Refinement Hit 86.52% on Terminal-Bench 2.1

Key Takeaways

  • Five-stage recursive self-improvement: alternates verified trajectory Recursive Self-Rewrite (RSR) with critic-inheriting Recursive Policy-Refine (RPR) on Qwen3.8-27B
  • Turn-Boundary Skip-Observation GAE (TB-GAE): retains token-specific baselines while decaying strictly across interaction turns rather than verbose shell output logs
  • State-of-the-art terminal performance: reaches 86.52% on Terminal-Bench 2.1, 79.00% on Terminal-Bench Hard, and lifts LHTB strict completion from 0/46 to 5/46
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AutoEnvScaling: Microsoft and Stanford Automate RL Environment Design via Terminal Agents, Unlocking 25x Data Flywheel

Microsoft Research and Stanford University have unveiled AutoEnvScaling, an automated data flywheel that frames RL environment creation itself as a terminal execution task. A proposer agent builds diverse environments directly from solver rollouts, slashing cost per valid environment by 75% while achieving a 25x higher valid environment yield over prompt-only baselines. Crucially, unifying environment design and solving within a single model enables Recursive Self-Improvement (RSI), yielding +12.2 points on Terminal-Bench 2.1 and doubling scores on Terminal-Bench 4.0.

AutoEnvScaling: Microsoft and Stanford Automate RL Environment Design via Terminal Agents, Unlocking 25x Data Flywheel

Key Takeaways

  • Environment design as a terminal task: shifts RL environment synthesis from manual curation to automated terminal execution, boosting valid yield by 25x
  • Unlocks Recursive Self-Improvement (RSI): enables a single backbone to co-evolve as both environment architect and task solver without human bottlenecks
  • Broad cross-domain generalization: yields a 12.2-point surge on Terminal-Bench 2.1 and doubles Terminal-Bench 4.0 for Qwen3.6-35B-A3B across kernel coding and OS tasks
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TerminalHorizon Released: Automated Data Synthesis Engine for Long-Horizon Terminal Agents Powers 27B Model to 55.8% on Terminal-Bench 2.0

As autonomous software engineering agents and command-line assistants evolve from single-turn tool invocation toward complex, multi-stage delivery, the scarcity of high-quality, long-horizon terminal interaction data has emerged as a fundamental bottleneck. Researchers from USTC, Alibaba Group (AMAP), and SUSTech introduce TerminalHorizon (arXiv:2610.13166), a fully automated data synthesis engine for training long-horizon terminal agents. Addressing standard pitfalls where synthetic environments oversimplify core challenges and eliminate the need for exploration, TerminalHorizon extracts workflows from real-world tasks, pinpoints omitted steps through independent execution loops, dynamically reconstructs environments based on observed evidence, and organically scales task complexity across multiple stages under unified objectives. Synthesizing 1.5K environments and 2,852 trajectories averaging 52.8 turns, the authors train TerminalHorizon-27B (fine-tuned on Qwen3.5-27B). The model achieves 55.8% on Terminal-Bench 2.0 (+14.2 points over base Qwen3.5-27B), sweeping 12 benchmarks across coding agents, production environments, and reasoning with project datasets open-sourced.

TerminalHorizon Released: Automated Data Synthesis Engine for Long-Horizon Terminal Agents Powers 27B Model to 55.8% on Terminal-Bench 2.0

Key Takeaways

  • TerminalHorizon automated synthesis engine releases 1.5K environments and 2,852 trajectories averaging 52.8 interaction turns
  • TerminalHorizon-27B attains 55.8% on Terminal-Bench 2.0, delivering a 14.2-point leap over base Qwen3.5-27B
  • Outperforms massive synthetic datasets on 12 benchmarks covering coding agents, terminal operations, and multi-step reasoning
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SWR: Self-Supervised Scaling of Scientific Terminal Environments for Coding Agents Surges Terminal-Bench 2 to 53.56%

Terminal coding agents are expanding from standard software engineering into scientific domains like bioinformatics, materials science, and physics. However, building training sandboxes requires executable reference behavior and rigorous verifiers capable of distinguishing true semantic correctness from superficial syntactic mimicry—a process that currently requires tedious manual engineering per task. Researchers from Tsinghua University and Tencent introduce Software-in-the-Loop Reconstruction (SWR, arXiv:2610.02710), a self-supervised environment scaling framework. SWR extracts ground-truth outputs and verifiers from existing executable scientific software workflows by perturbing input configurations into public observations and hidden evaluations. Agents synthesize complete, editable programs from input-output schemas without viewing source code, evaluated by hierarchical verifiers testing semantic fidelity, structural integrity, and anti-shortcut compliance. Implemented across 500 workflows and 46 software suites spanning six scientific domains, SWR generates 1,422 verified trajectories. Supervised fine-tuning of Qwen3.8-27B elevates Terminal-Bench 2 average success from 47.94% to 53.56%, establishing a scalable paradigm for scientific terminal agent training.

SWR: Self-Supervised Scaling of Scientific Terminal Environments for Coding Agents Surges Terminal-Bench 2 to 53.56%

Key Takeaways

  • Introduces SWR to bootstrap self-supervised terminal agent training sandboxes from existing scientific software workflows
  • Decouples public observations from hidden evaluations, using hierarchical verifiers to block shortcuts during program reconstruction
  • Drives Qwen3.8-27B performance on Terminal-Bench 2 from 47.94% to 53.56%, eclipsing all token-matched baseline controls
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Mid-Harness Scales Action Compute at Model-Harness Boundary for Terminal Agents, Driving Pass@1 from 50% to 68%

Terminal agents execute stochastic model outputs directly in real bash environments, where an erroneous command (e.g., misconfigured dependency install, file deletion) irreversibly corrupts system state and derails downstream progress. Researchers introduce Mid-Harness, a paradigm that allocates test-time compute precisely at the boundary between model generation and the evaluation harness. By sampling and verifying candidate actions before sending them to the terminal—rather than expensively generating multiple full rollout trajectories—Mid-Harness elevates Pass@1 on TerminalBench-Lite from 50.00% to 68.03% under action scaling, achieving vastly higher reliability at substantially lower token cost.

Mid-Harness Scales Action Compute at Model-Harness Boundary for Terminal Agents, Driving Pass@1 from 50% to 68%

Key Takeaways

  • Pioneers Mid-Harness to allocate test-time compute at the model-harness boundary before terminal execution
  • Catapults Pass@1 on TerminalBench-Lite from 50.00% to 68.03% via 8-action sampling under capable verification
  • Proves action scaling achieves superior success rates at lower token budgets compared to full trajectory scaling
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Developer 'A vs B' comparison intent surges: Sonnet 5.5, Sol, Argon, Air, and Copilot Computer Use collide in one week

Over ~7 days, Claude Sonnet 5.5, GPT-6.1 Sol, Gemini 4 Argon, JetBrains Air in IDEs EAP, and GitHub Copilot Computer Use landed in the same window. Search and HN discourse shifted from single-release chase to pairwise selection on price bands, terminal agents, IDE harnesses, and computer-use. Meta industry brief for readers without X.

Key Takeaways

  • Same-week cascade: Sonnet 5.5 in Copilot (09-28) → Sol in Copilot (09-29) → Argon Fairwind preview (09-30) → Air EAP + Copilot Computer Use (10-01)
  • Hot pairs: Sonnet↔Opus, Sonnet↔Sol, Argon↔Opus/Astra, Air↔Cursor, Copilot CU↔Claude CU, Codex↔Claude Code, Sol↔Astra same-family economics
  • Selection axes: price band × terminal harness × IDE orchestration (Air ACP BYO) × computer-use for GUI-only legacy
  • Compliance caveat: Anthropic subscription auth ToS constrains third-party harnesses; Air docs allow Claude subscription via terminal full-screen tab only
  • Argon still Fairwind-gated (not GA); no public developer GA date—label comparison pages as preview-gated
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Mid-Harness Scales Actions at Model-Harness Boundary: Action Verification Lifts TerminalBench Pass@1 by 18%

Terminal agents operate through stochastic model generations, but a single errant command can irreversibly degrade sandbox environments. Mid-Harness introduces test-time compute scaling at the boundary between model and harness. By sampling and verifying candidate actions before terminal dispatch without modifying the underlying generator or harness, Mid-Harness boosts Pass@1 on TerminalBench-Lite from 50.00% to 68.03% under a GPT-5.6 Sol verifier, outperforming whole-trajectory scaling at lower token expenditure.

Mid-Harness Scales Actions at Model-Harness Boundary: Action Verification Lifts TerminalBench Pass@1 by 18%

Key Takeaways

  • Allocates test-time compute at model-harness boundary, lifting TerminalBench-Lite Pass@1 from 50.00% to 68.03%
  • Pairwise action verification and distillation enable compact local models to filter errant commands effectively
  • Reduces estimated token overhead by over 35% compared to whole-trajectory sampling while increasing task completion
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Cline: GPT-6 Astra is live — pick gpt-6-astra via /model after npm install

Cline says GPT-6 Astra is live in its terminal agent: install cline globally, run /model, and select gpt-6-astra. After earlier Terminal-Bench leadership claims, this is the product-side hookup so developers can switch to OpenAI’s newest coding model in CLI agent workflows immediately.

Key Takeaways

  • Path: npm i -g cline, then /model and select gpt-6-astra.
  • Use case: terminal-native agent loops can run Astra for multi-step coding.
  • Timing: follows earlier Terminal-Bench teaser with product availability now.
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Anthropic launches Claude Code 2.0 with native AST dependency mapping and automated CI autofix workflows

Anthropic announced Claude Code 2.0, the next iteration of its terminal agent. Featuring a re-engineered AST syntax graph and symbol indexer, it cuts long-context token consumption by 45%. The release adds automated CI failure log ingestion and autonomous autofix loops for faster multi-file debugging.

Key Takeaways

  • Integrates native AST syntax topology and symbol indexing, cutting multi-file context usage by 45%.
  • Connects directly with CI test failures to generate and apply end-to-end verified fix patches.
  • Optimized for terminal CLI workflows and IDE subshell execution with extensible hooks.
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Anthropic Claude Code terminal agent introduces isolated subagent sandboxing for non-blocking concurrent fixes

Anthropic introduced subagent sandbox isolation to its CLI tool Claude Code. When orchestrating large refactors, the master agent can spawn lightweight subagents into isolated scratch environments to write tests, update documentation, and verify patches in parallel before merging into a unified Git commit.

Key Takeaways

  • Claude Code spawns parallel isolated subagents for decoupled task execution.
  • Isolated scratch worktrees prevent unverified test artifacts from polluting repos.
  • Automatically aggregates test results into clean, standard Git commit history.
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Alibaba Qwen open-sources Qwen3-Coder-480B agentic coder and Qwen Code CLI

Alibaba's Qwen team open-sourced Qwen3-Coder-480B-A35B-Instruct, an open agentic coding model with 256k native context (extensible to 1M) and top-tier SWE-bench Verified marks. Alongside the weights, Qwen open-sourced Qwen Code, a terminal agent CLI for autonomous project refactoring.

Key Takeaways

  • 480B total / 35B active MoE architecture sets new standards on SWE-bench Verified.
  • 256k native context with 1M extrapolation ingests large monolithic codebases.
  • Open-source Qwen Code CLI delivers an out-of-the-box autonomous terminal agent.
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