Hey everyone, we’re Adi and Sven, cofounders of Reason Machines 👋
TL;DR We built the most efficient agent harness, so teams can maximize their AI usage at up to 30% lower cost per task than Codex, Cursor or Devin. Sessions run on cloud VMs that move across your devices, use your existing keys and subscriptions, and work directly in Slack.
Since launching 4 weeks ago: 20,000 users, 14,000 X followers, and 3M+ impressions.
the problem
AI models are finally good enough for real work. The bottleneck is no longer capability—it’s cost: how much work you get per dollar of inference.
That cost is set by the harness more than the model—the same model can cost up to 5× more depending on the harness. Today, teams are stuck choosing between simple chat bots that can’t touch infrastructure, and closed cloud platforms that lock you into one vendor’s models and markup.
the solution
We designed a minimal harness for the most work per token, with the power of a cloud VM and the ease of a Slack bot:
Cloud VMs that follow you Runs across cloud Linux, a cloud Mac, your own Mac or an SSH box without losing state.
Swarm-scale parallelism Run hundreds of sessions in parallel to ship a feature, or let workflows run for days.
BYO keys & subscriptions Plug in your API keys, open weights, and Grok, Copilot, or Kimi subscriptions with auto-failover.
Slack-native Mention @Reason in a thread to get back a PR, a deck, or an answer.
the harness
A minimal harness (bash + async code execution) beats labs' bloated harnesses on cost per task without sacrificing capability. On the Coding Agent Index, Reason scored 65.1 vs Codex’s 62.5, at 22% lower cost per solved task. Read the full benchmark write-up.
team
Adi and Sven studied EECS at UC Berkeley. Adi worked in applied ML at Scale AI and previously built a Rust-based IDE; Sven built AI models at a Fortune 100 company. We dropped out to build what a self-driving company runs on.
More AI usage, for less cost.
our ask
Try it Add @Reason to Slack or start on the web. YC companies get $1,000 in credits through the Reason deal on Bookface.
Intros We’d love introductions to teams hitting AI usage limits, or paying heavy bills for Codex, Cursor or Devin.
We’re raising our seed round If you can introduce us to investors, reach us at founders@reasonmachines.com.