Long Horizon

Environments deliberately designed to take hours or days of agent effort: sprawling codebases, multi-stage projects, tasks with delayed and sparse rewards. Long-horizon coherence is the axis on which current frontier models improve fastest, and these environments are how that improvement gets measured and trained.

14 companies · 8 cataloged artifacts · as of 2026-08-16

Name	Domains	Type / catalog	Location	Team	Funding	Raising
Andon Labs Long-horizon autonomy benchmarks like Vending-Bench	Long Horizon, Alignment	Pure-play commercial Catalog unknown	San Francisco	1-10	Seed (Y Combinator)	Unknown
Andromede Programmatic generation of long-horizon RL environments	Long Horizon	Pure-play commercial Catalog unknown	Lausanne	1-10	-	Unknown
Anthromind Medical and long-horizon environments and expert data	Medical, Long Horizon, Data Labeling	Data + environments Catalog unknown	San Francisco	1-10	-	Unknown
ARIMLABS Security and long-horizon environments for agentic AI	Cybersecurity, Long Horizon	Pure-play commercial Catalog unknown	Warsaw	11-25	-	Unknown
Collinear Enterprise simulation, judges, and long-horizon trajectory generation	Enterprise, Long Horizon, Machine Learning, Simulation	Pure-play commercial Catalog unknown	Mountain View, Sunnyvale	11-25	-	Unknown
Diffuse Labs ML and long-horizon RL environments	Machine Learning, Long Horizon	Pure-play commercial Catalog unknown	Palo Alto, San Francisco	1-10	-	Unknown
EdotEnv Long-horizon planning environments for frontier models	Long Horizon, Machine Learning	Pure-play commercial Catalog unknown	San Francisco	1-10	-	Unknown
General Reasoning Open reasoning data and reward models from the ex-Meta AI reasoning lead	Finance, Long Horizon, Machine Learning	Pure-play commercial Catalog unknown	London, San Francisco	1-10	~$10.9M (reported)	Unknown
Good Start Labs Game-based RL environments and benchmarks	Games, Long Horizon	Pure-play commercial Catalog unknown	Brooklyn, New York, Toronto	1-10	~$3.6M (reported)	Unknown
HUD Evals and RL environments platform for computer-use agents	Computer Use, Coding, Long Horizon, Environment Platforms, Custom Environments	Environment platform Catalog unknown	San Francisco, Singapore	11-25	$15M raised (YC W25, Exceptional Capital)	Unknown
Huzzle Labs Long-horizon code, tool-use, and enterprise workflow environments	Long Horizon, Coding, Enterprise	Pure-play commercial Catalog unknown	London, Berlin, San Francisco	26-50	~$6M (reported)	Unknown
pre.dev Software-planning platform offering coding and long-horizon RL environments	Coding, Long Horizon	Pure-play commercial Catalog unknown	Delaware	1-10	-	Unknown
Proximal Long-horizon coding RL environments built from real codebases	Coding, Long Horizon	Pure-play commercial Catalog unknown	San Francisco, Bangalore	26-50	-	Unknown
Tacit Labs Life-science and long-horizon environments for AI models	Science, Long Horizon	Pure-play commercial Catalog unknown	San Francisco	1-10	-	Unknown