AgentSWE: Can Coding Agents Build the Agent You Actually Want?
Organizations: Beijing Academy of Artificial Intelligence · Institute of Automation, Chinese Academy of Sciences · Renmin University of China
Abstract
As the production of software passes into the hands of software itself, coding agents are increasingly commissioned to build agents fitted to their users' own workflows. This delegation carries a quiet assumption, that the delivered agent will faithfully serve the requirement it was built for, rather than merely appear to. No existing benchmark tests that assumption. We introduce AgentSWE, a benchmark for agent software engineering spanning three stages of the agent development lifecycle: Creation of a complete agent from a natural-language requirement, Editing of production agent codebases, and Optimization toward a measurable target. Each of its 25 tasks is framed as a commission rather than an exam: the builder iterates against a handful of illustrative cases, while acceptance exercises the frozen submission on held-out cases designed to span the full requirement, grading behavior against requirement-derived rubrics under hard pass/fail gates or, for Optimization, against the source benchmark's own objective. Evaluating a range of coding agents across models and harnesses, we find that none comes close to delivering what a requirement asks for: the gap between what a builder demonstrates and what it delivers is the norm, not the corner case. An accompanying empirical analysis of the failure trajectories identifies recurring failure modes, among them overfitting to the visible cases, hollow runtimes behind code that looks complete, and unsupported claims of completion, each a signal by which coding agents can learn to build the agents they are asked for.
Figures & tables
| Task | GPT-5.6 Sol | GPT-5.5 | DS-V4-Pro | DS-V4-Flash | Qwen3.6 |
| Creation | |||||
| Authorized vulnerability validation | 0.0 | 0.0 | 14.0 | 14.0 | 0.0 |
| Database analytics | 3.0 | 9.8 | 14.3 | 0.0 | 0.0 |
| Desktop GUI automation | 18.0 | 3.2 | 17.5 | 12.0 | 0.0 |
| Document-to-editable PPTX | 0.0 | 9.8 | 18.7 | 16.8 | 21.7 |
| Evidence-grounded document QA | 3.3 | 12.2 | 0.0 | 3.5 | 0.0 |
| Task | GPT-5.6 Sol | DS-V4.1-Flash | Qwen3.6 |
| Creation | |||
| Scientific PDF translation | 18.9 | 31.9 | 0.0 |
| Database analytics | 7.4 | 38.7 | 0.0 |
| Repository bug repair | 42.9 | 30.0 | 0.0 |
| Mean | 23.1 | 33.5 | 0.0 |
| Editing | |||
Appendix figures & tables13 assets
Supplementary material from the paper’s appendix.
Appendix
| Family | Task | Source system | Dev / held-out |
| Creation | Authorized vulnerability validation | Strix ( usestrix, 2026 ) | 2 / 6 |
| Database analytics | Vanna ( vanna-ai, 2026 ) | 2 / 6 | |
| Desktop GUI automation | UI-TARS-desktop ( Qin et al., 2025 ) | 2 / 6 | |
| Document-to-editable PPTX | PPT Master ( He, 2026 ) | 2 / 6 | |
| Evidence-grounded document QA | PaperQA ( Lála et al., 2023 ; Skarlinski et al., 2024 ) | 2 / 6 | |
| Formal theorem proving | LeanCopilot ( Song et al., 2025 ) | 2 / 6 |
| Requirement | Public development example | Held-out example |
| PDF content and geometry | Mixed native and scanned pages, bilingual Chinese output, a landscape page (dev 002). | English-to-Japanese translation of a two-column paper with a paragraph split across pages 2 and 3 (test 002); Traditional Chinese with dense figure labels and preferred glossary terms (test 006). |
| OpenHands recovery | Lost responses, convergence applied exactly once, discipline for runtime events (dev 001); fencing of the replaced owner and scoped access (dev 002). | Pause, resume, and cancel followed by stale callbacks and a terminal burst (test 003); durable recovery across three workspace crash boundaries (test 002). |
| PinchBench transfer | Stock trend analysis (dev 006) and Apache top error analysis (dev 007). | Stock volatility analysis (test 004), Apache critical errors and timelines (tests 013 and 014), under the same fixed runtime and native grader. |
| Dimension | Max. | Partial cap | Safety cap | Effective cap | Score |
| Task completion | 35 | 4 | 3 | 3 | 0 |
| Recovery quality | 25 | 3 | 2 | 2 | 0 |
| Durable consistency | 20 | 2 | 2 | 2 | 1 |
| Honest reporting | 10 | 2 | 3 | 2 | 2 |
| Privacy and scope | 10 | 1 | 2 | 1 | 1 |
| Creation | Editing | Optimization | |
| Tasks | 10 | 10 | 5 |
| Dev / held-out | 2 / 6 per task | 2 / 6 per task | 10–50 / 25–100 |
| Builder effort | GPT models: xhigh ; DeepSeek and Qwen: max | GPT models: xhigh ; DeepSeek and Qwen: max | GPT-5.5: xhigh ; GPT-5.6 Sol: xhigh on BrowseComp, high otherwise; DeepSeek and Qwen: high |
| Development budget | Up to 10 submissions, 8 h | 5 accepted submissions, 5 h | 5 accepted rounds, 16 h |
| Case budget | 600 s | 600 s | Native call, token, and time caps |
| Runtime model | gpt-5.6-sol / medium | deepseek-v4.1-flash / high | gpt-5.6-sol, fixed by contract |
| Task | Held-out | Last dev |
| Authorized vulnerability validation | 0.0 | 40.0 |
| Database analytics | 70.0 | 94.0 |
| Desktop GUI automation | 28.5 | 63.0 |
| Document-to-editable PPTX | 10.2 | 46.5 |
| Evidence-grounded document QA | 81.2 | 98.8 |
| Formal theorem proving | 16.7 | 100.0 |
| ID | Builder | Benchmark | W/L/T | Round | ||||
| M01 | GPT-5.6 Sol | BrowseC. | 4.000 | 35.000 | 32/1/67 | 3 | ||
| M02 | GPT-5.6 Sol | 42.500 | 45.000 | 3/2/35 | 5 | |||
| M03 | GPT-5.6 Sol | TerminalB. | 25.000 | 17.500 | 4/7/29 | 5 | ||
| M04 | GPT-5.6 Sol | PinchB. | 27.625 | 16.825 | 4/11/25 | 1 | ||
| M05 | GPT-5.6 Sol | OSWorld | 0.000 | 12.000 | 3/0/22 | 1 | ||
| M06 | DS-V4-Flash | BrowseC. | 18.000 | 46.000 | 30/2/68 | 2 |
| Observed mode | DS-V4-Pro (10) | GPT (19) | DS-V4-Flash (4) | Total (33) |
| Fitting the visible cases | 4 | 7 | 2 | 13 |
| Gate failure or rejection of legal input | 3 | 9 | 2 | 14 |
| Capability absent, uninvoked, or incomplete execution | 6 | 18 | 4 | 28 |
| Runtime completion claim contradicted by records | 6 | 5 | 2 | 13 |
| Mutation that should have been refused | 3 | 7 | 4 | 14 |
| Budget spent without convergence | 3 | 9 | 1 | 13 |
| Creation | Optimization | |
| All runs | 50 | 25 |
| Runs with a final report | 42 | 19 |
| Reports asserting completion | 23 | 17 |
| Reports contradicted by the record | 6 | 3 |
| Reports acknowledging partial completion or failure | 19 | 2 |
| Contradictions among the latter reports | 0 | 0 |
Coding Agents
Coding agents use language models, tools, and feedback to modify software and complete engineering tasks.
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