Reason Machines
Reason is the AI teammate for work and code.
Reason Machines at a glance
- Y Combinator batch
- Spring 2026
- Status
- Active
- Industry
- B2B
- Team size
- 2 people
- Location
- Not recorded
- Website
- Not recorded
Every field above comes from the Y Combinator company record. Nothing is estimated.
About Reason Machines
Reason is an AI teammate for work and code that runs autonomous cloud agents with a frontier harness on cost per task. It delivers the same performance with 22% lower costs than Codex. By operating with a harness outside the sandbox, it acts seamlessly across cloud computers and local devices. Reason runs work from start to finish: from an issue to a finished pull request, on a schedule, or from a Slack alert. It is available as a Mac app, on the web, from the CLI, in Slack, and through a REST API, with about 100 integrations and shareable skills. Bring your own keys and subscriptions, and work rolls over to the next one when limits are hit.