Wayfinder: An Agentic Ensemble-and-Postcheck System for WMT26 GenMT

Liangying Shao, Xinwei Wu, Yichong Huang, Jifang Wang, Ruoxi Xu, Ling Shi, Baosong Yang, Linlong Xu


Abstract
This paper presents Wayfinder, our submission system for the WMT26 General Machine Translation (GenMT) shared task. GenMT evaluates document-level translation under natural-language instructions, where structural preservation, formatting constraints, and output cleanliness are part of translation quality. Rather than training a new translation model, Wayfinder treats four API-based system outputs as a document-level candidate pool and produces one final hypothesis through a four-stage agentic pipeline. It aggregates source, instruction, metadata, candidates, and a DeepSeek-V4-Pro ranking-then-scoring signal; applies an anonymized pick-or-rewrite agent; and runs a conservative postcheck for severe objective defects. During development, a judge-guided loop compares outputs with a GPT-5.5 baseline, analyzes loss cases, updates prompts and repair constraints, and selectively reprocesses difficult documents. In automatic pairwise evaluation against GPT-5.5, Wayfinder obtains a pooled document-level weighted win rate of 0.6537 and remains above parity in every evaluated direction. The results suggest that candidate-pool translation, constrained agentic selection, conservative repair, and selective judge-guided iteration are practical components for instruction-conditioned shared-task MT.
Anthology ID:
2026.wmt-main.78
Volume:
Proceedings of the Eleventh Conference on Machine Translation
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Barry Haddow, Tom Kocmi, Philipp Koehn, Christof Monz
Venues:
WMT | WS
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1405–1413
Language:
URL:
https://aclanthology.org/2026.wmt-main.78/
DOI:
Bibkey:
Cite (ACL):
Liangying Shao, Xinwei Wu, Yichong Huang, Jifang Wang, Ruoxi Xu, Ling Shi, Baosong Yang, and Linlong Xu. 2026. Wayfinder: An Agentic Ensemble-and-Postcheck System for WMT26 GenMT. In Proceedings of the Eleventh Conference on Machine Translation, pages 1405–1413, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Wayfinder: An Agentic Ensemble-and-Postcheck System for WMT26 GenMT (Shao et al., WMT 2026)
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PDF:
https://aclanthology.org/2026.wmt-main.78.pdf