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UPDATED 2026.10.05
rl-list.com · Vendors · BenchFlow
#15

BenchFlow

Commercial
medium confidence
www.benchflow.ai ↗ · Status: active confirmed · Founded 2024

BenchFlow is a small, open-source-first 'frontier environment lab' in the Bay Area. It publishes agent benchmarks and environments: SkillsBench and ClawsBench, the env0 simulated workspaces, Robo Use and GenesisBench for embodied agents, and FrontierPhysics. It runs the PostTrain Arena for community-contributed post-training environments and maintains an Apache-2.0 runtime for RL environments, post-training and evals. It has event-level ties to Google DeepMind, Kaggle, Anthropic, Hugging Face and Prime Intellect.

Key facts
Headquarters
San Francisco Bay Area, CA, USAconfirmed cite
Headcount band
1-10reported cite
Total raised
– cite
Last round
Unconfirmed. An aggregator reports a $1M seed (Jan 2025), but the founder stated on X on 2026-06-25 'We didn't even raise a seed'. No priced round has been announced.reported cite
SOC 2
unknown
What they sell
environmentsconfirmed cite
Open source
yesconfirmed cite
Deployment
Self-hosted open-source runtime (CLI + Python SDK; sandboxes via Docker, Daytona, Modal, AWS AgentCore, Vertex); hosted public benchmark sites and leaderboardsconfirmed cite

What's new

10 sourced updates · last 6 months

Founding team

Xiangyi Li
Founder & CEO
Previously worked on coding-model inference and inference at Tesla. First author of SkillsBench and ClawsBench; co-organizer of Agent Skills '26.
Kirk Xu
Co-founder (reported; listed by Founders, Inc.)
Named as a founder only on the Founders, Inc. portfolio page. Not shown on BenchFlow's own About page. A GitHub account 'kirk-xuhj' has 17 commits to the runtime. Background unknown.
Moritz Wallawitsch
Former early co-founder (reported departure Feb 2025)
Listed as an early co-founder who left in February 2025, per the startupintros aggregator only. No longer with the company.

What practitioners should know

For researchers

  • Two arXiv papers, both first-authored by founder Xiangyi Li: SkillsBench (2602.12670, Feb 2026, v4 Jun 2026; +16.6 pp from curated skills) and ClawsBench (2604.05172, Apr 2026).
  • SkillsBench and ClawsBench datasets are on Hugging Face (benchflow/SkillsBench, benchflow/ClawsBench). The SkillsBench repo has about 1.8k stars.
  • BenchFlow says SkillsBench is cited in the Qwen 3.6 Max model card. skillsbench.ai also points to citations in Tencent Hunyuan and Huawei openPangu model cards. These are self-reported; we did not check the model cards.
  • July 2026 env0 study: teacher-student SFT on simulated-workspace trajectories gave +69.4% relative on SkillsBench for Qwen3.5-9B, for $10.67 of H100 compute. The model is public at huggingface.co/benchflow/benchflow-qwen35-9b.
  • Moving into embodied and science evals: Robo Use (PyPI, Sep 2026), GenesisBench (Jul 2026), FrontierPhysics v0.1, and partner of the re:AGENT agentic-science build weekend (Aug 2026).

For program managers

  • Very small team. The About page lists 3 people: the founder plus two Members of Technical Staff (a Berkeley quantum-physics PhD and a Cornell CS student). Founders, Inc. also lists a team size of 3. Paper author lists and GitHub contributors show a wider academic collaborator network.
  • Frontier-lab ties are event-level only. Google DeepMind presented the SkillsBench launch party (with Kaggle), and Anthropic was a presenter of the re:AGENT event where BenchFlow was a partner. BenchFlow self-claims internal SkillsBench use at Google DeepMind, Meta, Microsoft, Tencent, GLM and MiniMax; this is unverified, and no commercial contracts are disclosed.
  • BenchFlow names Prime Intellect, Fireworks and Hugging Face (OpenEnv) as compute and ecosystem partners.
  • Funding is unclear. Aggregators report a $1M seed in Jan 2025 (YC, Pear, Construct, FAST/GETTYLAB, Ankit Jain), but the founder posted on X on 2026-06-25: 'We didn't even raise a seed.' Founders, Inc. is the only investor confirmed on the investor's own page. BenchFlow has no YC directory page. No priced round has been announced.
  • Mainly community and open-source driven: hackathons with 600+ participants and more than $100K in prize pools (Mar 2026), plus workshops and build weekends. The commercial engagement model is not publicly described.

For data ops

  • The runtime is Apache-2.0 with a CLI and Python SDK. Sandboxes run on Docker, Daytona, Modal, AWS AgentCore (with VPC support) and Vertex. The README lists Claude Code, Codex, Gemini, Goose, Qwen-Code and Prime-Agent as agents; release notes also mention OpenCode.
  • Native task package is task.md with environment and verifier sidecars. PostTrain Arena tasks are Docker env + verifier + oracle packages, submitted as public Hugging Face datasets.
  • Recent releases (Aug-Sep 2026) add URL-denylist egress enforcement, weighted rubric reviews, hf:// dataset sources, and trajectory upload with redaction and rate limiting.
  • Note the mixed licenses: the runtime is Apache-2.0, but the posttrainarena, env0 and artifacts repos are AGPL-3.0 and GenesisBench is GPL-3.0.
  • No SOC 2, certifications or trust page found.

Benchmarks & research

8 published
Robo Useenvironment · Sep 2026
Robot benchmarks recast as tasks that a coding agent solves by driving a simulated robot from its shell. BenchFlow's research page cites 341 tasks across 14 suites. On PyPI as robouse (first release 2026-09-21).
Blog research note on supervised fine-tuning of Qwen3.5-9B on trajectories from the env0 simulated workspace, with a Qwen3.5-397B-A17B teacher.
SkillsBench v1.1 rose from 7.01% to 11.88% (+69.4% relative). ClawsBench rose from 10.56% to 13.89% (+31.6% relative).
GenesisBenchbenchmark · Jul 2026
Benchmark of LLM agents building and improving robot policies, across MuJoCo, Genesis, Isaac Sim and RoboCasa environments. The GitHub repo (benchflow-ai/GenesisBench) was created 2026-07-07.
awesome-evalsdataset · 24 Jun 2026
Curated list of resources for building and evaluating AI agents (about 955 GitHub stars; repo created 2026-06-24).
PostTrain Arenaleaderboard · Jun 2026
Community arena that ranks contributed environment collections by the held-out pass-rate change after a fixed SFT-then-GRPO post-training run. Training runs are currently paused while the organizers fix the evaluation.
ClawsBenchbenchmark · 6 Apr 2026
Five high-fidelity, wire-compatible mock workplace services (Gmail, Slack, Calendar, Docs, Drive) with full state and snapshot/restore. Capability and safety are scored separately. Dataset on Hugging Face (benchflow/ClawsBench).
With full scaffolding, agents reach 39-64% task success but take unsafe actions 7-33% of the time (6 models, 4 harnesses). Without scaffolding, all six models score 0-8%.
SkillsBenchbenchmark · 13 Feb 2026
The first benchmark of whether procedural skills (instructions, scripts and references loaded on demand) make agents better at real tasks. The arXiv paper (v4, 2026-06-14) has 77 authors led by Xiangyi Li. The leaderboard is now at v1.1. Also on Hugging Face (benchflow/SkillsBench) and GitHub (about 1.8k stars).
Paper v4: curated skills raise the average pass rate from 33.9% to 50.5% (+16.6 pp). v1.1 leaderboard: GPT-5.5 + OpenHands leads at 67.3% with skills vs 51.5% without (skillsbench.ai).
FrontierPhysicsbenchmark · 2026
Open benchmark for end-to-end physics research by AI agents. v0.1 has 56 tasks across 9 domains, with contributions from 42 researchers at 38 institutions. No launch date is stated; it was not on the BenchFlow site at the 2026-06-07 baseline.
Claude Opus 5.5 leads at 22.0% overall pass rate, ahead of GPT-6 Astra at 14.9% (BenchFlow-run leaderboard).

Products

BenchFlow Runtime (open source) ↗
Apache-2.0 'Research infra for creating RL environments, post-training, and evals'. Supports single-agent, multi-agent (for example coder plus reviewer, or a simulated user) and multi-round runs. Sandboxes run on Docker, Daytona, Modal, AWS AgentCore and Vertex. Tasks use the native task.md package format. Includes a CLI and Python SDK, sandbox hardening to protect verifiers and hidden task data, and LLM rubric scoring. Latest release v0.7.8 (2026-09-15); about 353 stars.
SkillsBench ↗
Agent-skills benchmark and leaderboard (v1.1).launched Feb 2026
ClawsBench ↗
Simulated-workspace capability and safety benchmark.launched Apr 2026
env0 ↗
High-fidelity simulated Google Workspace and Slack services, used to generate post-training trajectories.launched Jul 2026
PostTrain Arena ↗
Community environment-contribution and post-training arena, supported by Hugging Face OpenEnv. Runs are currently paused.launched Jun 2026
Robo Use ↗
Embodied-agent environments ('agent as a policy for embodied agents'); pip install robouse.launched Sep 2026
GenesisBench ↗
Benchmark of language agents improving robot policies across simulators.launched Jul 2026
FrontierPhysics ↗
End-to-end physics-research agent benchmark and leaderboard (v0.1).

Scale & velocity

Current headcount
3 named team members (founder + 2 Members of Technical Staff) on the company About pageconfirmed cite
Headcount growth
unknown
Open roles
unknown
Other locations
unknown
Distributed / remote
unknown

Research depth

Has researchers
yesconfirmed cite
Researcher count
unknown
Backgrounds
Xiangyi Li (founder/CEO): previously coding-model inference at Tesla; first author of SkillsBench and ClawsBench, Bingran You (MTS): PhD in quantum physics, UC Berkeley; author of the env0 study, Carrie Chen (MTS): CS, Cornell; host of the Cornell RL research seminarconfirmed cite

Capital

Total raised
unknown (aggregator reports $1.0M; founder stated in Jun 2026 that no seed round was raised) cite
Last round
Unconfirmed. An aggregator reports a $1M seed (Jan 2025), but the founder stated on X on 2026-06-25 'We didn't even raise a seed'. No priced round has been announced.reported cite
Investors
Founders, Inc. (confirmed via its portfolio page), Y Combinator (reported by aggregator only; no YC directory page found), Pear VC (reported), Construct Capital (reported), FAST by GETTYLAB (reported), Ankit Jain (angel, reported)reported cite
Valuation
unknown
Revenue signals
unknown

Security & compliance

SOC 2
unknown
Other certifications
unknown
Security page
unknown cite

Product

What they sell
environmentsconfirmed cite
Open source
yesconfirmed cite
License
Apache-2.0confirmed cite
Deployment model
Self-hosted open-source runtime (CLI + Python SDK; sandboxes via Docker, Daytona, Modal, AWS AgentCore, Vertex); hosted public benchmark sites and leaderboardsconfirmed cite
Maturity
research preview / early-stage (multiple open benchmarks and an OSS runtime released frequently at v0.7.x; PostTrain Arena runs paused; very small team; funding status unclear)estimated cite
Notable customers
⚑Google DeepMind self-claimed (internal SkillsBench use); separately, GDM presented the SkillsBench launch event (verified on Luma) ⚑Meta self-claimed ⚑Microsoft self-claimed Tencent self-claimed Zhipu (GLM) self-claimed MiniMax self-claimed cite

Buyer analysis

Best fit: Teams needing open-source, reproducible agent evaluation environments and a runtime to benchmark coding/computer-use/workplace agents at low setup cost.

How we verified this

2026-10-05 refresh: I opened every source in the draft. Identity is confirmed: benchflow.ai and the benchflow-ai GitHub org, founder Xiangyi Li. Most product and research items held up against primary sources: arXiv abstracts, BenchFlow news posts, the Luma event pages, the workshop site, posttrain.com and the GitHub API. Corrections: - SkillsBench gain is +16.6 pp in paper v4 (draft said +16.4). - Release dates are now confirmed as 2026 through the GitHub API instead of inferred. - Undated news items were dated from PyPI and repo-creation records, or moved out of news (FrontierPhysics). - The Google DeepMind Build Day is now labelled self-reported. - An unverified agent (Cursor) was removed from the data-ops notes. Funding is the weak area. The founder's June 2026 'We didn't even raise a seed' post is now verified through X's embed endpoint, and BenchFlow has no YC directory page. The $1M seed and the YC/Pear/Construct investor list therefore stay aggregator-only and are flagged as contradicted. Founders, Inc. is the only investor confirmed on its own page. I added two items the researcher missed: GenesisBench (Jul 2026) and BenchFlow's partner role in the re:AGENT agentic-science weekend, which Anthropic and Arc Institute presented (Aug 2026). The founder headshot comes from the company's own About page and loads as a single-person image. Kirk Xu stays a reported co-founder with no photo. Customer claims (Google DeepMind, Meta, Microsoft, Tencent, GLM, MiniMax) are self-claimed benchmark users, not verified customers. Web search quota was exhausted during verification, so a broad sweep for press coverage was not possible. Missed-item checks relied on BenchFlow's own pages, the GitHub org and PyPI.

Related vendors

Sources

  1. www.benchflow.ai/ · 2026-10-05, Homepage: product list and events (Skillathon, CAIS workshop, SkillsBench launch party, GDM Enterprise Build Day, re:AGENT)
  2. www.benchflow.ai/about · 2026-10-05, Team (Xiangyi Li, Bingran You, Carrie Chen), headshots, Bay Area location, partners
  3. www.benchflow.ai/assets/team/xiangyi-li.webp · 2026-10-05, Founder photo: HTTP 200 image/webp; single-person photo of Xiangyi Li speaking
  4. www.benchflow.ai/news · 2026-10-05, Dated news list
  5. www.benchflow.ai/news/improving-skillsbench-with-env0 · 2026-10-05, env0 SFT study, 2026-07-02
  6. www.benchflow.ai/news/skillsbench-paper · 2026-10-05, Self-claimed internal users; Qwen 3.6 Max model card citation
  7. www.benchflow.ai/news/clawsbench-paper · 2026-10-05, ClawsBench announcement, 2026-04-07
  8. www.benchflow.ai/news/agent-skills-26-workshop · 2026-10-05, Workshop accepted at ACM CAIS 2026
  9. www.benchflow.ai/news/agent-skills-hackathon-ii · 2026-10-05, Hackathon II (Mar 2026), 600+ participants across both events, more than $100K in prizes
  10. www.benchflow.ai/research · 2026-10-05, Research index: SkillsBench, ClawsBench, Robo Use (341 tasks, 14 suites), PostTrain, FrontierPhysics
  11. www.benchflow.ai/frontierphysics · 2026-10-05, FrontierPhysics v0.1 and leaderboard
  12. www.benchflow.ai/docs/benchflow · 2026-10-05, Runtime docs: task.md format, CLI/SDK, sandbox hardening
  13. arxiv.org/abs/2604.05172 · 2026-10-05, ClawsBench paper abstract (v1 2026-04-06)
  14. arxiv.org/abs/2602.12670 · 2026-10-05, SkillsBench paper (v1 2026-02-13, v4 2026-06-14; +16.6 pp)
  15. skillsbench.ai/ · 2026-10-05, SkillsBench v1.1 leaderboard; model-card citation claims
  16. luma.com/deepmind-634c · 2026-10-05, SkillsBench 1.1 launch party presented by Google DeepMind, with Kaggle; 264 attendees
  17. luma.com/g6org075 · 2026-10-05, re:AGENT (Aug 15-16): presenters GXL, Anthropic, Arc Institute; BenchFlow listed as partner; Xiangyi Li listed as host
  18. www.agentskills-workshop.org/ · 2026-10-05, Agent Skills '26 workshop organizers and stats
  19. posttrain.com · 2026-10-05, PostTrain Arena: 'Brought to you by BenchFlow'; runs paused
  20. github.com/benchflow-ai/posttrainarena · 2026-10-05, PostTrain Arena repo (created 2026-06-08 per GitHub API; AGPL-3.0)
  21. robouse.ai · 2026-10-05, Robo Use, run by BenchFlow
  22. pypi.org/project/robouse/ · 2026-10-05, robouse 0.0.1 on 2026-09-21, 0.4.0 on 2026-10-04 (PyPI JSON API)
  23. genesisbench.benchflow.ai · 2026-10-05, GenesisBench site; NVIDIA GEAR papers appear only as cited related work
  24. github.com/benchflow-ai/GenesisBench · 2026-10-05, Repo created 2026-07-07 (GitHub API)
  25. github.com/benchflow-ai · 2026-10-05, Org repos, creation dates and star counts (GitHub API)
  26. github.com/benchflow-ai/benchflow · 2026-10-05, Runtime README: backends, agents, run modes; Apache-2.0; 353 stars; last pushed 2026-10-03
  27. github.com/benchflow-ai/benchflow/releases · 2026-10-05, Release notes v0.6.9 to v0.7.8; 2026 dates confirmed via the GitHub API
  28. f.inc/portfolio/benchflow/ · 2026-10-05, Founders, Inc. portfolio page: founders Kirk Xu and Xiangyi Li; team of 3
  29. x.com/xdotli/status/2070256643930255519 · 2026-10-05, Founder X post, 2026-06-25: 'Some of BenchFlow's early team ... We didn't even raise a seed'. x.com returned 402; text and date read via the public embed endpoint (cdn.syndication.twimg.com)
  30. www.ycombinator.com/companies/benchflow · 2026-10-05, Returns 404: no YC directory page
  31. startupintros.com/orgs/benchflow · 2026-10-05, Aggregator: $1M seed Jan 2025, investors, Moritz Wallawitsch departure (single source)
  32. tracxn.com/d/companies/benchflow/__n6eEhuEioOF6iyeia5-JulQQPuB9g_ddBiUaB · 2026-10-05, Tracxn lists Founders (Inc.) as the only institutional investor; round details paywalled
  33. docs.benchflow.ai/introduction · 2026-06-07, Official docs, Benchmark Hub + eval infra; RFT framework in development
  34. github.com/benchflow-ai/skillsbench · 2026-06-07, SkillsBench repo
  35. www.linkedin.com/company/benchflow-ai · 2026-06-07, Public snippet, 2-10 employees, founded 2024, Software Development; specialties 'Data and environments for agents to learn'
  36. www.linkedin.com/in/l1xiangyi/ · 2026-06-07, Founder Xiangyi Li, creator of SkillsBench
  37. www.inverse.com/tech/building-ais-testing-ground-benchflows-mission-as-e · 2026-06-07, Founder interview, founding story, background, no funding/customers named
  38. news.ycombinator.com/item?id=43440893 · 2026-06-07, Show HN: BenchFlow – run AI benchmarks as an API
  39. www.crunchbase.com/organization/benchflow · 2026-06-07, Crunchbase profile, returned HTTP 403 (not directly accessible)
  40. pitchbook.com/profiles/company/711737-02 · 2026-06-07, PitchBook profile (not fetched)
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.