Fleet AI builds high-fidelity reinforcement-learning training environments ('gyms') that replicate enterprise software such as Salesforce and Excel, plus browser/desktop workflows, so frontier AI labs and large enterprises can train and evaluate computer-use agents. It ships a Python SDK, a platform API, and the open-source 'Harbor' agent-evaluation/RL-environment tooling, pairing simulated environments with human supervision.
Raised
$15M
Headcount
11-50
Founded
2024
SOC 2
unknown
Researchers
yes
Open src
yes
Backers: Sequoia Capital, Menlo Ventures, SV Angel
AfterQuery is a San Francisco applied-research lab and data platform (YC W25) that supplies frontier AI labs with expert-generated human data (SFT, RL rubrics), agent/RL environments, and computer-use trajectories, drawn from a large network of verified practitioners. It publishes real-task benchmarks such as Terminal-Bench, VADER, FinanceQA, and IDE-Bench, positioning around capturing how domain experts (engineers, financial analysts, lawyers) reason.
Raised
$30.5M ↑ $30M
Headcount
51-200
Founded
2025
SOC 2
unknown
Researchers
yes
Open src
yes
Backers: Altos Ventures (lead, Series A), The Raine Group, Y Combinator
Veris AI sells a high-fidelity simulation platform plus a production runtime that let enterprises train, evaluate, and govern AI agents against mocked enterprise tools before and during production, with support for reinforcement learning / fine-tuning pipelines. It positions itself as the enterprise 'environment layer' that agent builders lack.
Raised
$8.5M
Headcount
1-10
Founded
2025
SOC 2
claimed
Researchers
yes
Open src
no
Backers: Decibel Ventures (lead), Acrew Capital (lead), The House Fund
HUD (YC W25, formerly hud.so) is a platform for building reinforcement-learning environments and evaluations for computer-use and browser agents. It lets teams wrap real software/code as agent-callable tools in isolated containers, define tasks and rewards, and run evals/RL at scale via an open-source SDK plus a cloud-hosted gateway. It maintains public benchmarks (OSWorld-Verified contributions, SheetBench-50) and positions frontier AI labs and agent-first startups as its target customers.
Raised
–
Headcount
11-50
Founded
2025
SOC 2
unknown
Researchers
yes
Open src
yes
Backers: Y Combinator (W25 batch), Exceptional Capital
Halluminate (YC S25, founded 2024, San Francisco) builds managed reinforcement-learning sandbox environments, simulated applications, and human/annotation data plus evaluation benchmarks (WebBench, BrowserBench, Westworld) to train and test computer-use and browser AI agents. Its 2026 site positioning has narrowed toward 'RL environments for financial services' (investment banking, private equity, consulting).
Raised
$160K
Headcount
1-10
Founded
2024
SOC 2
unknown
Researchers
yes
Open src
yes
Backers: Y Combinator (S25), Orange Collective, Antigravity Capital
Huzzle Labs is the AI division of London-based talent platform Huzzle (founded ~2020 by Ingmar Klein, Parham Rakhshanfar, and Amit Choudhary). It positions itself as a human-intelligence data foundry that builds RL environments (code, tool-use, computer-use, long-horizon enterprise workflows), expert trajectory data, and contextual evaluations for frontier AI labs and regulated European enterprises, leveraging Huzzle's vetted PhD/expert network. It bundles environments, human data, and evals in one stack.
Raised
$6M
Headcount
11-50
Founded
2020
SOC 2
Type II
Researchers
yes
Open src
partial
Backers: 10x Founders, Angel Invest, Emerge
BenchFlow is an early-stage, YC-backed open-source 'environment lab' building evaluation infrastructure and a community Benchmark Hub for AI agents, with products including SkillsBench, ClawsBench (mock workplace environments) and a sandboxed agent runtime. It positions environments as 'the new data' for training and evaluating agents across domains like enterprise workflows, coding, computer use and browser tasks.
Raised
$1.0M
Headcount
1-10
Founded
2024
SOC 2
unknown
Researchers
yes
Open src
yes
Backers: Y Combinator, Pear VC, Construct Capital
Collinear AI operates a 'Simulation Lab' (SimLab) that builds sandboxed, stateful RL environments simulating enterprise users, tools (Jira, ServiceNow, Shopify, EMR, airline/hotel systems) and multi-step workflows, producing training-ready trajectories, reward signals and evals for agentic models. It also offers synthetic post-training data and LLM-judge evaluation, positioning itself around 'environment-as-a-service' for enterprise long-horizon agents.
Raised
–
Headcount
11-50
Founded
2023
SOC 2
unknown
Researchers
yes
Open src
no
Backers: Engineering Capital, Firestreak Ventures, 112 Capital (11.2 Capital)
Plato (plato.so, Plato Technologies, Inc.) builds simulated worlds for training and evaluating browser and computer-use agents, recreating real websites/software (e.g. Amazon/Airbnb/Gmail-style replicas) as reinforcement-learning environments with structured APIs for interaction, state tracking and scoring. It also offers a 'Computer Use' capability driving a full Linux desktop, positioning at the intersection of browser interaction and enterprise workflow simulation.
Raised
–
Headcount
1-10
Founded
2025
SOC 2
unknown
Researchers
yes
Open src
no
Pedigree: Pranav Putta (Co-founder/CTO), prior MultiOn, Georgia Institute of Te
AIChamp builds custom reinforcement-learning environments and 'Virtual Gym' simulations for training and evaluating tool-using AI agents on long-horizon, multi-step enterprise tasks, pairing engineered environments (agents operating in software like Slack, Notion, Linear) with domain experts who design and grade tasks (SFT/RLHF/process supervision). The company emphasizes deep industry authority and expert-sourced data, having pivoted from a remote-talent/hiring marketplace background.
Raised
$0
Headcount
1-10
Founded
?
SOC 2
unknown
Researchers
?
Open src
no
Pedigree: Self-claimed 'alumni of OpenAI and xAI team' (vendor site, unverified)
Habitat Inc is an early-stage commercial vendor (2-10 employees, New York HQ) building reinforcement-learning environments for white-collar / work automation, with stated focus on code and desktop-style (computer use) interaction tasks for training agentic AI models. It appears in third-party listings of RL-environment suppliers serving AI labs. No funding, customer, or certification information is publicly available.
Raised
–
Headcount
1-10
Founded
?
SOC 2
unknown
Researchers
?
Open src
no
Pedigree: Maxim Enis (co-founder), Williams College '24; prior Ramp association
Scale AI is the data-labeling and AI-data incumbent that has extended into RL environments, offering simulated web apps, macOS/Windows-like desktop VMs, and MCP-tool environments (Slack, HubSpot, Linear) with expert-designed objectives, rubrics, and automated verifiers to train and evaluate agents on long-horizon professional workflows. Following Meta's ~$14.3B June 2025 investment (~49% non-voting stake) and founder Alexandr Wang's departure to Meta, several frontier-lab customers (OpenAI, Google, xAI) reportedly scaled back or paused engagement over conflict-of-interest concerns.
Raised
$1.6B
Headcount
200+
Founded
2016
SOC 2
Type II
Researchers
yes
Open src
no
Backers: Meta Platforms, Accel, Amazon
Mercor is a venture-backed expert-marketplace and AI-training-data company that organizes a network of ~30,000+ domain experts (doctors, lawyers, bankers, engineers) to produce RLHF data, evaluations, and reinforcement-learning environments for frontier AI labs and enterprises. Originally an AI-recruiting platform, it pivoted to human-data/RL services and expanded its RL-environment capability through acquisitions, including the February 2026 acquisition of Sepal AI and the July 2026 acquisition of Deeptune, whose computer-use/enterprise environment platform and NYC team joined Mercor.
Raised
$492M
Headcount
51-200
Founded
2023
SOC 2
unknown
Researchers
yes
Open src
no
Backers: Felicis Ventures (led Series C and Series B), Benchmark, General Catalyst
Surge AI is a bootstrapped, high-revenue human-data and RLHF labeling leader serving frontier AI labs, which has expanded into agentic RL environments via its EnterpriseBench suite (notably the CoreCraft enterprise customer-support simulation) and accompanying published benchmarks. As of June 2026 a reported ~$1B first external raise at a ~$25B valuation was in talks but not confirmed closed.
Raised
$1B
Headcount
51-200
Founded
2020
SOC 2
unknown
Researchers
yes
Open src
no
Pedigree: Founder/CEO Edwin Chen: ex-Google, ex-Facebook, ex-Twitter ML teams; M
Prime Intellect operates an open-source RL stack - the Environments Hub (2,500+ community RL environments), the Verifiers library and prime-rl training framework, plus hosted RL post-training (Lab), evals, inference and on-demand GPU compute. It positions itself as the open alternative to closed big-lab RL tooling and also trains open models (INTELLECT series).
Raised
$180M ↑ $130M
Headcount
11-50
Founded
2023
SOC 2
unknown
Researchers
yes
Open src
yes
Backers: Founders Fund (led $15M round), Menlo Ventures, Distributed Global (co-led seed)
Deeptune was a New York-based startup building managed reinforcement-learning environments ('training gyms') for computer-use and code, where AI agents practice and are evaluated on realistic digital knowledge-work tasks (simulating tools like Slack and Salesforce). It sold these pre-built environments primarily to frontier AI labs and raised a $43M Series A led by a16z (March 2026). In July 2026 it was acquired by Mercor; the team joined Mercor and Deeptune's environment platform now sits under Mercor. It is therefore no longer ranked as an independent vendor.
Raised
$43M
Headcount
11-50
Founded
2025
SOC 2
unknown
Researchers
yes
Open src
no
Backers: Andreessen Horowitz (a16z, lead), 776, Abstract Ventures
Sepal AI was a YC-backed (S24) San Francisco data-research company that built high-quality training data, expert-graded evaluation benchmarks, and reinforcement-learning environments for frontier LLMs, drawing on a network of 20k+ domain experts (PhDs, finance, medical, STEM). It was acquired by Mercor in February 2026; the team joined Mercor and its RL-environment and human-data work now sits under Mercor. It is therefore no longer ranked as an independent vendor.
Raised
$500K
Headcount
?
Founded
2024
SOC 2
unknown
Researchers
yes
Open src
no
Backers: Y Combinator, Metaplanet Holdings, SID Venture Partners
Turing is a large AGI-infrastructure and engineering-services company that supplies frontier AI labs with coding data, human expertise, and RL/evaluation data at scale, drawing on a global vetted developer and domain-expert network. Originally a remote-engineering talent marketplace, it now positions itself around 'AGI advancement' through code and reasoning data, including work over private/real codebases.
Raised
–
Headcount
200+
Founded
2018
SOC 2
unknown
Researchers
yes
Open src
no
HQ: Palo Alto, USA