Lensemble

Research stack for reproducible federated training and evaluation of action-conditioned JEPA world models.

Lensemble implements the model, participant, coordinator, aggregation, privacy, artifact, and evaluation machinery needed to study federated JEPA world models while participant trajectories remain local.

Research status

The code can execute joint encoder-and-predictor training through the federation stack. That software capability is not an achieved useful and gauge-stable scientific result. The checked-in full-model evidence predates correction of an outer-step sign defect and must be rerun before it supports new claims. The corrected research loop remains open in #335.

The optional browser experience is narrower: it performs federated continuation of a bounded residual adapter on a frozen LeWorldModel checkpoint. It is not full-model browser training.

Install

From a clean checkout:

uv venv .venv --python 3.11
uv pip install "torch>=2.4,<3" --index-url https://download.pytorch.org/whl/cpu
uv pip install -e ".[dev,docs]"

Validate the core loop

uv run pytest \
  tests/e2e/test_toy_pipeline.py::test_federated_round_commits_and_advances_the_global_hash \
  -q

This small CPU test runs two real participants through the in-process coordinator, closes a deterministic aggregation round, and verifies that the committed global hash advances. It is a software smoke test, not benchmark evidence.

Read by task

• Understand the system: architecture and federated protocol.
• Understand the central research problem: latent gauge and aggregation.
• Inspect evaluation contracts: evaluation protocol and dynamic-env metrics.
• Inspect the historical, pre-outer-step-sign-correction CPU investigation (the checked values require a corrected rerun and are not current-code reproduction evidence): full-model federation spike.
• Inspect public claim surfaces: historical Phase 3 model card and frozen-checkpoint adapter demo card.
• Use the Python package: API reference.
• Navigate the complete contract corpus: specification overview or repository index.

Optional browser demo

uv run lensemble demo federated --port 8765

Follow the printed local URL. Read the demo card before presenting its result.

Claim boundary

Lensemble is a research codebase. It is not a production federation service, a cryptographic proof system, a full-model browser trainer, or evidence of closed-loop physical robot success.