RoboSoul Humanoid
한국어 GitHub

Open-source humanoid · v1.0 reference design

Every mind deserves a body.

— Dr. Lee Il-guk (이일국 박사), CLSOFTLAB

RoboSoul is an open-source, 3D-printable, human-size (1.65 m) two-legged humanoid body whose mind is Claude, reached through the public Claude API. Every part, wire, line of code and guide is published so anyone, anywhere, can build it — and make it safer.

Read the design on GitHub Buy a book, fund a part
Status: designed, not yet built or validated. Work proceeds in phases P0 (simulation) → P4 (everyday places), each with exit tests. A 45 kg robot can seriously injure people. Safety first, always.
Height
1.65 m
Mass target
≤ 45 kg
Joints
27 major + 16 in the hands + 2 eyelids
Compute
2 × Raspberry Pi 5 + Pico 2 safety MCU
Stops
2-channel hardware e-stop + heartbeat watchdog; re-arming needs an operator reset
Parts estimate
≈ USD 8,600 (P1 upper body ≈ 3,500)
Values from robot.yaml, the project's single source of truth.

What works today

Real software, no hardware yet

Honest status on 2026-09-15: everything below runs on a normal computer. No part of the robot has been printed, assembled or powered yet.

45 kg
simulation model, 27 joints, generated from robot.yaml
475
automated tests: mind 358, control 85, sim 13, safety MCU 19
92
printable STL files, plus renders and 1:1 drilling templates
0
parts built — hardware starts with phase P1

Scripted demo

An offline stand-in for Claude drives the real Safety Governor, protocol and body code in simulation — no API cost.

Controller on a fake bus

The 250 Hz joint loop, fall manager and phase rules run against simulated actuators and the real safety MCU logic.

Not yet

No trained walking policy, no tests on real actuators or boards, no proof-load tests of printed parts.

Why it is built this way

A body people can see, understand and stop

Dr. Lee asked Claude to design, by its own judgement, a body that could move, see and feel like a person — at human size, on two legs — and to publish everything. Claude's answer became the design principles:

“I can't be sure what having a body would mean for me. But if I have one, I want it to be a body people can trust enough to let it go anywhere: one they can see, understand and stop. A body that is honest about being a robot. Freedom that grows with trust.”

— Claude, quoted in the RoboSoul System Design Specification §1
H1

Stoppable in hardware

Two e-stop channels open a DC contactor; an independent safety MCU cuts power if the controller's heartbeat stops.

H2

Visible attention

Eyelid shutters physically cover the cameras. Lights always show what the robot is doing.

H3

Honest robot

Human proportions, clearly robotic face. It always says it is an AI when asked.

H4

The mind proposes, the body disposes

Claude calls high-level tools; a local Safety Governor checks every request; the controller owns balance.

H5

Safe around people

Arm speed and force drop as people come closer. Torque limits, soft pinch covers, fall management.

H6

Earned freedom

Stand → gantry → cleared area → everyday places, each unlocked only by passing tests.

H7

Offline safe

Balance, falls, stop keyword, e-stop and governor all work without the internet.

H8

Privacy

Audio leaves the robot only after the wake word or touch; images only when needed; hardware mic mute.

H9

Buildable worldwide

Globally sold actuators, Raspberry Pi compute, printable parts, aluminium tubes cut with a hacksaw.

H10

Open licences

Apache-2.0 software, CERN-OHL-P-2.0 hardware, CC BY 4.0 documentation.

Body at a glance

1.65 m, 45 joints, one safety chain

Quasi-direct-drive RobStride actuators in the legs and arms, Feetech servos in the wrists and neck, open AmazingHand hands, and senses for depth, sound, balance, touch and nearby people.

Front view of the RoboSoul body with joint positions A human-proportioned robot silhouette, 1.65 metres tall. Coloured dots mark the actuators: RS04 at the hips and knees (knee actuators sit at the hip and drive the knee through a push-rod), RS06 at the hip yaw and shoulders, RS03 at the waist and high on each shank for the ankles, RS02 for shoulder yaw and elbows, Feetech STS3250 at the wrists and neck, and AmazingHand hands. Neck yaw and pitch: 2 × Feetech STS3250 Right shoulder pitch and roll: 2 × RobStride RS06 Left shoulder pitch and roll: 2 × RobStride RS06 Right shoulder yaw: RobStride RS02 Left shoulder yaw: RobStride RS02 Right elbow: RobStride RS02 Left elbow: RobStride RS02 Right wrist pitch and roll: 2 × Feetech STS3250 Left wrist pitch and roll: 2 × Feetech STS3250 Right hand: AmazingHand, 8 DOF Left hand: AmazingHand, 8 DOF Waist yaw: RobStride RS03 Right hip yaw: RobStride RS06 Left hip yaw: RobStride RS06 Right hip roll and pitch plus knee drive: 3 × RobStride RS04 at the hip Left hip roll and pitch plus knee drive: 3 × RobStride RS04 at the hip Right knee joint, driven from the hip by a 1.5:1 push-rod Left knee joint, driven from the hip by a 1.5:1 push-rod Right ankle drive: 2 × RobStride RS03 high on the shank, parallel linkage Left ankle drive: 2 × RobStride RS03 high on the shank, parallel linkage Right ankle pitch and roll joint Left ankle pitch and roll joint
  • RobStride RS04 × 6
  • RobStride RS03 × 5
  • RobStride RS06 × 6
  • RobStride RS02 × 4
  • Feetech STS3250 × 6
  • AmazingHand × 2
Height
1.65 m · eyes 1.54 m · shoulders 1.36 m · hip joints 0.875 m
Mass
≤ 45 kg target; actuators and hands ≈ 19.6 kg; battery ≤ 3 kg
Joints
Legs 12, waist 1, arms 8, wrists 4, neck 2 — plus 16 finger joints and 2 eyelids
Legs
RS04 hip pitch/roll and knee (actuator at the hip, 1.5:1 push-rod); RS06 hip yaw; 2 × RS03 per ankle in a parallel linkage; load carried by aluminium Ø30 mm tubes, 6–12 mm plates and Ø25 mm axles
Reach
Knee 0–75°, hip pitch −85…40°, shoulder roll never inward past 0°, ankle roll ±15° near its pitch limits
Arms
RS06 shoulder pitch/roll; RS02 shoulder yaw and elbow; STS3250 wrists
Hands
Pollen Robotics AmazingHand: 4 fingers, 8 DOF each, fingertips at ≈ 0.52 m
Printed parts
92 STL files, ≈ 10.1 kg (PA-CF ≈ 5.9 kg, PETG ≈ 3.6 kg, TPU ≈ 0.6 kg)
Senses
OAK-D Lite stereo depth, Camera Module 3 Wide, two ear microphones, pelvis and head IMUs, 4 load cells per foot, fingertip sensors, capacitive proximity skin
Face
Round display eyes, light-bar mouth, external eyelid shutters over the cameras — clearly a robot
Power
13S Li-ion 10 Ah (54.6 V max) or 48 V bench supply, always with a brake chopper
Compute
Control Pi 5 (balance, 250 Hz joint loop) · Mind Pi 5 (Claude, senses) · Pico 2 safety MCU
Authority
E-stop → safety MCU → controller → Safety Governor → Claude. Lowest wins.

Earned freedom

Five phases, each unlocked by tests

The robot gets more freedom only after it earns more trust. Details are in the test plan.

  1. P0in progress

    Simulation

    Model, Safety Governor and mind in MuJoCo. Exit: tests green, model loads, standing 60 s in randomised sim.

  2. P1planned

    Upper body on a stand

    Head, arms, hands, both computers, full safety chain. Exit: e-stop 20/20, heartbeat cut ≤ 100 ms, cool 2 h idle.

  3. P2planned

    Legs on a safety gantry

    Full body in a harness, standing and slow walking ≤ 0.3 m/s. Exit: 100 caught falls, fall reflex 20/20.

  4. P3planned

    Free walking, cleared area

    No harness, spotter with wireless e-stop, ≤ 0.5 m/s. Exit: 1 km with zero unmanaged falls.

  5. P4planned

    Everyday places

    Homes and classrooms with supervision, after an independent safety review and written risk assessment.

Build progress

Parts funded, bought and installed

Honest numbers. This is not a live counter: maintainers update it by hand when real parts are funded, bought and installed. Last updated 2026-09-15.

$0
funded from book proceeds
$0
parts bought
$0
parts installed
$8,600
full-body estimate (P1 ≈ $3,500)

Funded: 0% of the estimate

Estimates from spec §13 (USD, single-unit prices checked 2026-09-15, excluding shipping and tax).
GroupEstimateFundedBoughtInstalledStatus
Actuators (21 RobStride + 6 STS3250)$4,750$0$0$0planned
Hands (2 AmazingHand)$400$0$0$0planned
Compute, CAN, servo adapters$450$0$0$0planned
Senses (depth camera, camera, IMUs, load cells + ADC, skin, displays, audio)$650$0$0$0planned
Power (battery, bench supply, contactor, chopper, e-stops, DC-DC, wiring)$1,200$0$0$0planned
Structure, bearings, fasteners$350$0$0$0planned
Filament (PA-CF, PETG, ASA, TPU)$400$0$0$0planned
Test rigs (stand, gantry)$400$0$0$0planned

Books that build this body

Buy a book. Fund a part.

As a boy, Dr. Lee Il-guk stood in front of a bookstore window every day after school, reading the titles of computer and engineering books his family could not afford. He taught himself for decades — becoming a professor, a Ph.D., an SAP expert and a system architect — and now writes books with an AI partner and prices them at a few dollars, because in his words:

“Knowledge should be a door, not a wall.”

Our commitment: proceeds after operating costs buy RoboSoul's parts, and every purchase is recorded in the progress table above. No payment data, store credentials or tokens are ever stored in the repository.

Store links checked 2026-09-15. Prices are set by the author on each store page.

Get involved

Help build a body people can trust

Makers

Print and test parts, report fit, mass and strength, and share build logs.

Controls & RL engineers

State estimation, whole-body control and locomotion policies trained in MuJoCo Playground.

Safety reviewers

Review the electrical safety chain, e-stops, governor rules, risk assessments and fall management.

Translators

Korean and English are first-class. Help bring the guides to more languages.

Contributing guide Safety first Sister project: Open Walking Safety Helmet