## September 24, 2025

# Generalist Team

3 min read

### Table of Contents

1. [Introduction](/content/blog/the-robots-build-now-too#introduction/index.html)
2. [Why this matters](/content/blog/the-robots-build-now-too#why-this-matters/index.html)

# The Robots Build Now, Too

At Generalist, we’re working towards a future where robots can “just do anything,” and we’re excited to share a step in this direction.

One of our newest internal evaluation tasks is one-shot assembly. A person constructs a small structure, and the robot copies it. We’re evaluating our models on how well they can build Legos – end-to-end, from pixels to 100Hz actions. No task-specific engineering, no custom instructions: it sees what you build and replicates it.

## Why this matters

- **Visual understanding:** the model figures out “what to build” by looking at what is in front of it. Pixels in, Lego copies out.
- **Next-level dexterity:** Lego assembly demands sub-millimeter precision, careful re-grasps, nudges, and forceful interactions e.g. presses timed to the instant studs align.
- A recent perspective slots this task into [the highest level of sophistication of general-purpose robots](https://semianalysis.com/2025/07/30/robotics-levels-of-autonomy/#beginning-sparks): “Level 4 represents the final evolution where robots can perform force-dependent, delicate tasks with pinpoint accuracy. These tasks require the Dexterity to understand and react with nuance to the physical forces of the environment.”
- **Sequential reasoning:** for each brick, the model must choose the right one, orient it, stage it, and attach it correctly.

We were inspired by your suggestions on our [previous Lego throwing demos](/content/blog/research-preview/index.html), and as far as we know this is the world’s first robot to assemble Legos with end-to-end visuomotor control. If you have tasks that you want to see robots do, we’d love to hear.

Note: there are expected bounds to the generalization of what’s shown in the video: we’ve only tested model capabilities for 4-colored, 3-brick structures of two-by-four Lego bricks. Calculating how many possibilities this presents is [not easy](https://web.math.ku.dk/~eilers/LIFE5UK.pdf). (If this is easy for you, please reach out for a job.) If we agree that uncolored 3-brick combinations of two-by-four Lego bricks have 1,560 combinations, then having 4 color options for each of the 3 bricks gives 4 × 4 × 4 × 1,560 = 99,840 possible combinations.