Cassie is a dynamic bipedal robot developed by Agility Robotics, an Oregon-based company spun out of Oregon State University. First produced in 2016–2017, Cassie is a legs-and-torso-only robot — no arms, no upper body — built to study and demonstrate robust dynamic walking and running. It descends directly from the ATRIAS research robot developed in Jonathan Hurst's Dynamic Robotics Laboratory, and it is the platform on which Agility's locomotion technology was first commercialized before the arms-equipped Digit superseded it.
Availability
Cassie was sold primarily to universities and research institutions, not to general or industrial buyers, and it is no longer Agility's active product — the company's current robot is Digit. There is no official current list price. A commonly cited third-party estimate places Cassie around $300,000, reflecting its low production volume and research-grade nature; treat that as an estimate, not a current quote.
If you want a current Agility robot, the path is Digit, not Cassie.
Full Specifications
| Spec | Value |
|---|---|
| Configuration | Bipedal legs + torso only (no arms, no upper body) |
| Weight | ~31 kg |
| Walking/running speed | ~1.39 m/s |
| Runtime | ~5 hours on a single charge |
| Power | Battery, untethered operation |
| Autonomy | Partially autonomous; research-controlled |
| First produced | 2016 (introduced 2016–2017) |
| Lineage | ATRIAS → Cassie → Digit |
Notable feats
Cassie's defining public moment came in 2021, when it completed a 5-kilometer course on the Oregon State campus untethered on a single charge, finishing in just over 53 minutes (including resets after two falls). It was the first bipedal robot to use machine learning to control a running gait on outdoor terrain, and it also became adept at climbing and descending stairs. Its development was supported in part by a DARPA grant.
Model Breakdown
Cassie was offered as a single research configuration. Agility's framing was explicit: most Cassie customers were locomotion-control researchers specifically interested in legged-gait problems. When Agility wanted to reach a broader audience interested in applications rather than locomotion itself, it built Digit instead.
Buyer's Guide: What to Know
Cassie is for locomotion research only. With no arms and no manipulation capability, Cassie is a platform for studying bipedal walking, running, balance, and reinforcement-learning controllers — nothing else.
It is effectively legacy hardware. Agility's roadmap (Cassie → Digit v1 → v2 → v3 → v4) has moved on. New buyers should evaluate Digit; Cassie is most relevant to labs continuing existing research lines or seeking a pure-locomotion testbed.
It has a strong academic pedigree. Cassie remains a well-documented platform in the bipedal-locomotion literature, which is part of its enduring research value.
Cassie vs Similar Robots
- Cassie vs Agility Digit: Digit is the direct successor — it adds a sensor-rich torso, a head, and two arms (originally ~4 DOF each) for balance, fall recovery, and manipulation. Digit is a commercial logistics humanoid; Cassie is a locomotion-only research robot.
- Cassie vs Unitree G1: Both have served as research platforms, but the G1 is a full humanoid with arms, hands, and a software SDK; Cassie is legs-only and locomotion-focused.
- Cassie vs Boston Dynamics Atlas: Both pushed dynamic bipedal capability, but Atlas is a full humanoid built for whole-body agility and (now) industrial work, while Cassie deliberately strips the problem down to the legs.
Source: Agility Robotics
