RL List.com
UPDATED 2026.10.05
rl-list.com · Vendors · HUD
#9

HUD

Commercial
high confidence
www.hud.ai ↗ · Status: active confirmed · Founded 2025

HUD (Human Union Data, YC W25, formerly hud.so) calls itself the platform for building high-quality post-training datasets. It offers an MIT-licensed SDK for defining RL environments, tasks and graders across coding, browser, computer-use and robotics; a hosted training and eval platform; and DataVendor, a marketplace where independent builders sell RL environments and data to AI labs. It announced a $16M Series A led by Standard Capital in June 2026.

Key facts
Headquarters
San Francisco, USAconfirmed cite
Headcount band
11-50reported cite
Total raised
$16Mconfirmed cite
Last round
Series A, $16M (announced 2026-06-18), led by Standard Capitalconfirmed cite
SOC 2
claimedreported cite
What they sell
environments + platform (SDK, training and eval platform, DataVendor environment and data marketplace)confirmed cite
Open source
yesconfirmed cite
Deployment
managed-hosted + self-hosted (open-source SDK run locally or on owned infrastructure; hosted platform with REST API, TrainingClient and model gateway; Docker, Modal and Daytona runtimes; Fireworks RL integration documented)confirmed cite

What's new

8 sourced updates · last 6 months

Founding team

Jay Ram
Co-founder & CEO
YC bio: 'prev: consumer apps, ml research, quant research'.
Lorenss Martinsons
Lorenss Martinsons
Co-founder & Co-CEO (previously listed as CPO)
Cognitive Science background at Yale (per FounderTrace). Wrote HUD's 2025 'HUD Autonomy' post on agent evaluation.
Parth Patel
Parth Patel
Co-founder & CTO
Focuses on evals and RL environments (per FounderTrace). Co-authored the 2026-09 Browserbase x HUD browser-task post.

What practitioners should know

For researchers

  • Open research posts: Assemble Bench and CG-DAgger for VLA robotics (2026-07-31), LiveWeb browser-eval reliability with Browserbase (Browserbase 2026-09-22, HUD 2026-09-28), and 'What is a good task?' on task and grader design (2026-09-22).
  • Open releases under hud-evals on Hugging Face: AssembleBench dataset, two pi0.5 AssembleBench checkpoints, SheetBench-50, OSWorld-Verified, SpreadSheetBench, Online-Mind2Web-Tiny. On GitHub: assemble-bench, liveweb-samples, hud-ops-diagnostics (all MIT where checked).
  • The SDK's TrainingClient turns graded eval runs straight into training data (every rollout returns a trace_id and a reward), so you can bring your own GRPO or PPO. Documented RL paths exist for Daytona sandboxes and Fireworks Serverless RL.

For program managers

  • $16M Series A announced 2026-06-18, led by Standard Capital. Angels include Roon (OpenAI), Dylan Patel (SemiAnalysis) and Ivan Burazin (Daytona). Valuation is undisclosed.
  • Self-reported scale: 50+ businesses on the platform, 1.3M+ task runs, 2,500+ environments created, 15M+ inference calls, and a marketplace moving 'millions' a month. These are unaudited company claims.
  • Engagement is now a platform plus a marketplace (DataVendor), where third-party builders sell environments to labs. Check the provenance and QA of any environment sourced through the marketplace.
  • Published plan tiers on the homepage: SDK + Platform access free, Cloud at $0.10 per environment-hour, Enterprise custom, Academic $100 in free credits for .edu emails.
  • Team of 24 on the YC profile with about 30 open roles. Offices are in SF and Singapore. Lorenss Martinsons is now listed as Co-CEO next to CEO Jay Ram.
  • No frontier-lab customer is publicly confirmed by name. Public lab ties are the OSWorld-Verified feedback co-acknowledgement and an OpenAI employee (Roon) investing as an angel. Current homepage logos show only Sharpe and UiPath (UI-CUBE), both self-claimed.

For data ops

  • The SDK connects over MCP, CDP browser control, RFB/VNC computer use, SSH shell and files, and robot control over WebSocket (beta). Environments can be declared as Docker Compose projects (since v0.6.13, 2026-08-07).
  • Harbor interoperability is documented: Harbor tasks can be imported as HUD tasksets and Compose artifacts, and HUD tasks exported to Harbor folders.
  • Robotics data is published in LeRobot format. The HF org also shows a 'datavendor-test-lerobot' dataset.
  • PyPI package renamed from hud-python to `hud` in v0.6.10 (2026-07-15). Update pinned dependencies.
  • Security: the homepage claims 'SOC 2 compliant infrastructure' for the Enterprise plan, but there is no public SOC 2 report or trust center. A current YC posting for a Senior Security Engineer says the hire will 'Own SOC 2 and customer trust, including ... audits'. Ask for the attestation letter or report. The only legal document found is the DPA at hud.ai/dpa.
  • REST API reference and an LLM-readable docs index at docs.hud.ai/llms.txt.

Benchmarks & research

5 published
Four MIT-licensed live-site browser tasks open-sourced from HUD's LiveWeb set: ladybird-spot-num (Sketchfab), diamond-rose-seats (chair counting), epa-air-quality (AirNow) and costco-login.
Self-reported: on Ladybird, GPT-6 Astra averaged 93.3%, Claude Fable 56%, and Claude Sonnet 5 and Qwen 3.8 Max 0%. On AirNow, 20 of 21 runs got full marks. On Costco login, all four models scored 75%.
Assemble Benchbenchmark · 31 Jul 2026
Simulated robotics benchmark (Isaac Lab Arena, MIT licence) of 14 contact-rich assembly tasks in 4 families (round pegs, square pegs, gears, nuts), modelled on the NIST Assembly Task Board. Ships with a 1,355-episode demonstration dataset (hud-evals/AssembleBench on Hugging Face) and pi0.5 checkpoints (pi05-AssembleBench-12k, pi05-AssembleBench-cgdagger-r3).
Self-reported: after CG-DAgger rounds trained only on the 8mm round-peg task, pi0.5 improved dense reward on the 12mm and 16mm round pegs, with little transfer to 4mm. Sparse task success stayed limited at all sizes.
Hierarchical orchestrator and subagent environment (Sentry, Supabase, Kubernetes, with Railway also integrated) built on 24 real production debugging tasks. Available on the platform as 'cross-service-diagnostics'.
Self-reported: a Sentry subagent fine-tuned from o4-mini with OpenAI RFT improved from 6.3% to 13% success, about 2x.
SheetBench-50benchmark · 1 Oct 2025
50 financial-analyst spreadsheet tasks (29 data preparation, 16 derivation/extraction, 5 modelling/forecasts), built with Sepal AI and finance professionals from PwC, Cisco, Charles Schwab and Fannie Mae.
XLANG Lab's refreshed desktop computer-use benchmark (369 tasks per Cua). XLANG thanks 'Human Data' (HUD's earlier name and hud.so domain) among institutions that 'provided feedback and participated in the fixes'. HUD hosts a runnable version but did not author the benchmark.

Products

HUD SDK (`hud` package, formerly hud-python) ↗
MIT-licensed Python framework for defining environments, tasks and graders. It connects over SSH, MCP, CDP (browser), RFB/VNC (computer use) and a beta robot WebSocket, with native Claude, OpenAI and Gemini harnesses. TrainingClient turns graded rollouts into RL training data. Install with pip install hud (renamed on PyPI 2026-07-15).launched 2025
Training + Eval Platform ↗
Hosted platform for running evals at scale, viewing traces, managing tasksets and environments, and RL training from graded rollouts. It has a REST API and an OpenAI-compatible model gateway.
DataVendor ↗
Marketplace connecting independent RL-environment and data builders with model labs. HUD says it moves 'millions' a month (self-reported).launched 2026
HUD docs and cookbooks ↗
Documentation including Harbor interoperability, Compose environments, and Daytona RL, Fireworks Serverless RL, robot-benchmark and ops-diagnostics cookbooks. An LLM-readable index is at docs.hud.ai/llms.txt.

Scale & velocity

Current headcount
~24 (per YC profile, accessed 2026-10-05)reported cite
Headcount growth
growing (YC team size 15 to 24 between 2026-06-07 and 2026-10-05; ~30 open roles)reported cite
Open roles
31reported cite
Other locations
Singaporeconfirmed cite
Distributed / remote
partial (SF and Singapore offices; most roles open to remote in Asia or North America)confirmed cite

Research depth

Has researchers
yesreported cite
Researcher count
unknown
Backgrounds
Jay Ram (CEO) - consumer apps, ML/quant research (YC bio), Lorenss Martinsons (Co-CEO) - Cognitive Science, Yale (FounderTrace), Parth Patel (CTO) - evals and RL environments, Named research authors: Lukass Kellijs (robotics), Ilya Kuhta and Reinis Salaks (evals/task design), Shriya Lolabattu (browser evals), Team described as including Olympiad medalists and ICLR/NeurIPS-published researchers (carried over from the 2026-06 baseline; not re-verified)reported cite

Capital

Total raised
$16M+ (Series A $16M plus an undisclosed seed)confirmed cite
Last round
Series A, $16M (announced 2026-06-18), led by Standard Capitalconfirmed cite
Investors
Standard Capital (Series A lead), Y Combinator (W25), Exceptional Capital, Liquid 2 Ventures, Twenty Two Ventures, Dylan Patel (SemiAnalysis, angel), Roon (OpenAI, angel), Ivan Burazin (Daytona, angel), Theo Browne (angel)confirmed cite
Valuation
unknown
Revenue signals
Self-reported: 50+ businesses on platform; vendor marketplace moves 'millions' monthly; 1.3M+ task runs, 15M+ inference callsreported cite
DateRoundAmountLed by
18 Jun 2026Series A$16MStandard Capitalsource ↗

Security & compliance

SOC 2
claimed (homepage: 'SOC 2 compliant infrastructure' on Enterprise plan); no public report or trust center foundreported cite
Other certifications
unknown
Security page
https://www.hud.ai/dpa (Data Processing Addendum)reported cite

Product

What they sell
environments + platform (SDK, training and eval platform, DataVendor environment and data marketplace)confirmed cite
Open source
yesconfirmed cite
License
MITconfirmed cite
Deployment model
managed-hosted + self-hosted (open-source SDK run locally or on owned infrastructure; hosted platform with REST API, TrainingClient and model gateway; Docker, Modal and Daytona runtimes; Fireworks RL integration documented)confirmed cite
Maturity
GAestimated cite
Notable customers
UiPath self-claimed Sharpe self-claimed ⚑OpenAI self-claimed ⚑Anthropic self-claimed cite

Buyer analysis

Best fit: Teams that want to build, evaluate and RL-train agents on reproducible environments (computer-use, browser, coding, robotics), or that want to buy or sell RL environments through a marketplace.

How we verified this

2026-10-05 refresh: I opened every primary source the draft cited and nearly all of it held up. The $16M Series A (Standard Capital lead, YC, Exceptional, Liquid 2, Twenty Two, four angels) is confirmed by HUD's blog post (dated 2026-06-30). An fxtwitter mirror confirms the X announcement went out on 2026-06-18, which is now the event date. The YC profile confirms the founders, Lorenss Martinsons's new Co-CEO title, a team size of 24 and Active status. The three YC avatar photo URLs return single-person JPEGs. The homepage confirms the three-product repositioning, the self-reported metrics, the Sharpe and UiPath case studies, the 'SOC 2 compliant infrastructure' claim and the legal name Human Union Data, Inc. I made these corrections: the Assemble Bench result overstated success gains (only dense reward improved); the LiveWeb figures were imprecise; the Browserbase collaboration first appeared 2026-09-22 on Browserbase's blog, now added as third-party corroboration; the Daytona/Fireworks item had an unsupported date and 'partnership' framing, so I re-sourced it to GitHub release notes (Compose and Harbor 2026-08-07, Fireworks 2026-08-19, Daytona around early September) and recategorised it as product; the SOC 2 job-posting source was replaced with the live YC posting; DoorDash was removed from customers, since the draft's own evidence showed it is gone from the homepage. I added material the draft missed: the PyPI rename to `hud` (2026-07-15), managed Claude Code and Codex CLI agents (2026-09-25 pre-release) and the officially published plan tiers. Web search was unavailable to me because the session's search budget was exhausted, so I checked for missed funding, acquisitions or frontier-lab deals only by direct fetches of HUD's blog, research index, X profile, Hugging Face org, GitHub releases and the Browserbase blog. None of those showed an acquisition, shutdown or named frontier-lab customer, but third-party press coverage could not be swept independently. Frontier-lab customer claims remain unproven.

Related vendors

Sources

  1. www.hud.ai/blog/announcing-16m-series-a · 2026-10-05, Series A post dated 2026-06-30: $16M, Standard Capital lead, investors and angels, self-reported metrics, products, SF and Singapore
  2. api.fxtwitter.com/hud_evals/status/2067646134332567770 · 2026-10-05, Mirror of HUD's X Series A post (x.com/hud_evals/status/2067646134332567770), created 2026-06-18 16:30 UTC; mentions $16M, YC, Standard Capital and 50+ companies
  3. www.hud.ai/blog · 2026-10-05, Blog index: Series A post dated 06.30.2026
  4. www.hud.ai/ · 2026-10-05, Homepage: three products, self-reported metrics, Sharpe and UiPath case studies, SOC 2 claim, plan tiers, legal name Human Union Data, Inc.
  5. www.ycombinator.com/companies/hud · 2026-10-05, Founders, titles (CEO, Co-CEO, CTO), photos and links; team size 24; status Active
  6. www.ycombinator.com/companies/hud/jobs · 2026-10-05, 31 open roles with locations
  7. www.ycombinator.com/companies/hud/jobs/fi9ZRlo-senior-security-engineer · 2026-10-05, Senior Security Engineer posting: 'Own SOC 2 and customer trust, including ... audits'
  8. www.hud.ai/careers · 2026-10-05, SF and Singapore offices; 30 roles
  9. foundertrace.com/companies/hud_yc_w25/ · 2026-10-05, Founder backgrounds (Martinsons: Cognitive Science, Yale; Patel: evals and RL environments)
  10. github.com/hud-evals/hud-python · 2026-10-05, SDK: MIT, 306 stars, connection types, harnesses, TrainingClient, pip install hud
  11. github.com/hud-evals/hud-python/releases · 2026-10-05, v0.6.16 (2026-09-10) through v0.6.19.dev2 (2026-09-26); managed Claude Code and Codex CLI agents; Daytona runtime
  12. github.com/hud-evals/hud-python/releases?page=2 · 2026-10-05, v0.6.10 (2026-07-15, PyPI rename to hud) through v0.6.16.dev1; Compose, Harbor and robot stack (v0.6.13, 2026-08-07); Fireworks cookbook (v0.6.14, 2026-08-19)
  13. docs.hud.ai/llms.txt · 2026-10-05, Docs index: Harbor interoperability, Compose, Daytona, Fireworks, robot benchmark and ops-diagnostics cookbooks, REST API
  14. docs.hud.ai/v6/cookbooks/daytona-rl.md · 2026-10-05, Daytona RL cookbook: 256 parallel graded rollouts; no partnership terms stated
  15. www.hud.ai/research · 2026-10-05, Research index with dates and authors
  16. www.hud.ai/research/assemble-benchmark · 2026-10-05, Assemble Bench and CG-DAgger (2026-07-31)
  17. github.com/hud-evals/assemble-bench · 2026-10-05, Assemble Bench repo: MIT, Isaac Lab Arena, 14 tasks, checkpoints
  18. www.hud.ai/research/can-you-trust-your-browser-eval · 2026-10-05, HUD x Browserbase LiveWeb research (dated 2026-09-28), results by model
  19. www.browserbase.com/blog/browserbase-hud-frontier-evals · 2026-10-05, Browserbase's side of the collaboration (2026-09-22), co-authored by Parth Patel, Ilya Kuhta and Shriya Lolabattu
  20. github.com/hud-evals/liveweb-samples · 2026-10-05, Four LiveWeb sample tasks, MIT
  21. www.hud.ai/research/what-is-a-good-task · 2026-10-05, Task-design framework (2026-09-22)
  22. www.hud.ai/research/debugging-rl-environment · 2026-10-05, Ops-diagnostics RL environment (2026-01-20): 24 tasks, o4-mini RFT, 6.3% to 13%
  23. www.hud.ai/research/sheetbench-50 · 2026-10-05, SheetBench-50 (2025-10-01), Sepal AI
  24. huggingface.co/hud-evals · 2026-10-05, 19 datasets and 2 robotics models, including AssembleBench and pi0.5 checkpoints
  25. xlang.ai/blog/osworld-verified · 2026-10-05, OSWorld-Verified (2025-07-28) acknowledgement of 'Human Data' among feedback and fix contributors
  26. www.cua.ai/blog/hud-agent-evals · 2026-10-05, Cua x HUD integration (2025-08-27/28); OSWorld-Verified has 369 tasks
  27. arxiv.org/abs/2607.28367 · 2026-10-05, Checked and excluded: no HUD authors or mention
  28. pypi.org/project/hud-python/ · 2026-06-07, PyPI package for hud-python
  29. docs.hud.ai/ · 2026-06-07, Deployment model: cloud-hosted + local CLI, containerized isolated environments, OpenAI-compatible gateway at inference.hud.ai (Claude/GPT/Gemini/Grok); no SOC2/license stated in docs
  30. www.hud.ai/case-studies/sheetbench-50 · 2026-06-07, SheetBench-50 developed with Sepal AI; finance professionals from PwC/Cisco/Charles Schwab/Fannie Mae involved
  31. www.hud.ai/dpa · 2026-06-07, Data Processing Addendum page
  32. www.workatastartup.com/companies/hud · 2026-06-07, Team described with Olympiad medalists and ICLR/NeurIPS researchers (via search snippet)
  33. newsletter.semianalysis.com/p/rl-environments-and-rl-for-science · 2026-06-07, Technical description: HUD wraps software in dockerized container + MCP server exposing agent tools
  34. www.linkedin.com/company/hud-evals · 2026-06-07, Correct LinkedIn handle for HUD (YC W25) RL-environments company
  35. www.crunchbase.com/organization/hud · 2026-06-07, Crunchbase profile (HTTP 403 on fetch); funding not verified
  36. x.com/hud_evals/status/1919262852088570225 · 2026-06-07, HUD X post: hiring research engineers, works with frontier labs to evaluate CUAs
Last updated 2026-10-05 · Every quantitative field carries a source and a confidence tag. Fields we could not source publicly are marked unknown, never estimated. See the methodology.