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Jev Pick And Place Study

A MuJoCo pick-and-place pilot that runs Jev, Claude Haiku and hand-written reactive rules through the same episodes and publishes the comparison, including the parts that did not flatter Jev.

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1
Language
Python
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Community
Author
tryaksh
Last verified
Oct 2026

A small reproducible MuJoCo pilot comparing Jev, Claude Haiku, and reactive rules for pick-and-place.

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Updated Sep 2026

Repo stats from the GitHub API, cached Oct 2026.

About this project

A small, reproducible MuJoCo pilot exploring whether Jev can choose the actions for a pick-and-place task, and how that compares with Claude Haiku and simple rules. The aim is to support an honest research discussion and build on it later. Watch the demo · Results table · Full results · Evaluation traces. Ten unseen starting seeds, each tested normally and with a target change after lifting: 20 episodes per controller. Same observations, small actions, motion controller, success test, and 100-decision limit.

Quoted from the project's README. Read the full README.

Highlights

  • Rules and Jev each cleared 10 of 10 ordinary and 10 of 10 changed-target episodes; Haiku managed 4 and 1.
  • Jev chose the same action sequence as the rules controller in all 20 episodes, with no task-performance advantage from AI.
  • Median decision time was 146 ms for Jev against 732 ms for Haiku, with API cost quoted per successful run.
  • The demo replays from a bundled trace archive with no API key: unzip evaluation_traces.zip, then run demo.py render.

Watch out

The README is direct about the limits of its own result: this is one engineered interface and prompt setting, not a general model ranking. Haiku ran with structured action-only output and thinking disabled. The shared motion controller already follows the current target, so the changed-target result is not evidence of sophisticated AI replanning. Success requires a grasped lift, transfer, release, retraction and stable placement, and there is no vision or training involved. Twenty trials are exploratory evidence, and completion estimates add measured decision time to simulated duration, so they are not hardware cycle times. The commands are PowerShell for Windows with Python 3.11 and uv. Paid runs are capped at $1 for Jev and $5 for Claude, and the per-evaluation API spend quoted is $0.0695 for Jev against $2.0870 for Claude. Copy reviewed against the repository README on 2026-10-04, not from running it.

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