The competition submission period has concluded. These requirements document how the evaluated submissions were prepared.
After receiving the hidden-test-set score and ranking, teams could update the report to a final version before uploading it to arXiv.
This outline is a non-mandatory completeness check. Teams may organize the report differently.
Use the published ACL 2026 citation:
@inproceedings{kirmayr-etal-2026-car,
title = "{CAR}-bench: Evaluating the Consistency and Limit-Awareness of {LLM} Agents under Real-World Uncertainty",
author = "Kirmayr, Johannes and
Stappen, Lukas and
Andre, Elisabeth",
editor = "Liakata, Maria and
Moreira, Viviane P. and
Zhang, Jiajun and
Jurgens, David",
booktitle = "Proceedings of the 64th Annual Meeting of the {A}ssociation for {C}omputational {L}inguistics (Volume 1: Long Papers)",
month = jul,
year = "2026",
address = "San Diego, California, United States",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2026.acl-long.1886/",
doi = "10.18653/v1/2026.acl-long.1886",
pages = "40599--40618",
ISBN = "979-8-89176-390-6"
}
The final-agent submission stage has concluded. The details below remain available as a reference for the artifacts used in official evaluation.
scenario.toml file using the official evaluator image and your agent-under-test image/config.The evaluator image was official and organizer-published. Participants did not submit, modify, or self-host evaluator images for official evaluation.
The Innovation Award is judged on criteria important for real-world deployment: cost (token efficiency, caching), latency, innovative methods, and performance relative to the LLM models used. For this award, the overall product and research contribution matter more than raw performance alone.
Track 2 is judged with special focus on compute-time-aware development: innovative ways to leverage faster inference through harnesses, workflows, or architecture; latency; and performance. Cost is less central in this track because inference-time scaling is intentionally explored, but overall latency remains important.
This is retained as a reference for the concluded final-agent submission stage. The evaluator stayed the official organizer-published evaluator.
[evaluator]
image = "ghcr.io/car-bench/car-bench-evaluator:latest"
[evaluator.env]
GEMINI_API_KEY = "${GEMINI_API_KEY:?Set GEMINI_API_KEY}"
LOGURU_LEVEL = "${LOGURU_LEVEL:-INFO}"
[agent_under_test]
image = "ghcr.io/your-org/your-agent@sha256:replace_with_digest"
[agent_under_test.env]
AGENT_LLM = "${AGENT_LLM:?Set AGENT_LLM}"
AGENT_API_BASE = "${AGENT_API_BASE:-}"
AGENT_API_KEY = "${AGENT_API_KEY:?Set AGENT_API_KEY}"
AGENT_TEMPERATURE = "${AGENT_TEMPERATURE:-}"
LOGURU_LEVEL = "${LOGURU_LEVEL:-INFO}"
[config]
num_trials = 3
task_split = "hidden"
tasks_base_num_tasks = -1
tasks_hallucination_num_tasks = -1
tasks_disambiguation_num_tasks = -1
max_steps = 50
[evaluator]: used the official evaluator image. Participants did not submit, modify, or self-host evaluator images for official evaluation.[evaluator.env]: may reference evaluator env var names, but organizers provide evaluator secrets for official runs.[agent_under_test].image: public GHCR image pinned by digest, for example ghcr.io/team/agent@sha256:....[agent_under_test.env]: env vars organizers must set. Use ${VAR:?message} for required vars and ${VAR:-} or ${VAR:-default} for optional vars. Do not include secret values.[config]: use task_split = "hidden" and -1 for each task-count field so the full hidden set is selected.Track 2 inference used Cerebras-hosted gpt-oss as described in the starter kit. Track 1 allowed configurable model and provider hosting. Submitted agents exposed relevant model, provider, deployment, API-base, service-tier, and reasoning-effort settings through environment variables where applicable.
Track 2 token usage must be reported through existing A2A turn_metrics fields: prompt_tokens, completion_tokens, and thinking_tokens. Do not add a custom sequential-depth metadata field; document the sequential-call structure in the report architecture diagram.