[Question] Proposal: Add Train–Inference Consistency Data Collection to slime

Your Question

Background

We appreciate the slime team’s work. As an RL framework, slime is strong in engineering readiness and issue diagnosis, especially in key stages such as rollout and training updates.

In practice, we find that slime currently lacks train–inference consistency data collection. We would like to discuss with the authors whether this capability can be upstreamed.

Why This Matters

In MoE-based RL workloads, train–inference consistency is critical. Systematic forward-pass divergence can distort reward / KL signals, or in severe cases cause training divergence or policy collapse. Root causes are often complex (e.g., operator numerics, data types, framework adaptation). With train–inference consistency data collection, differences can be localized quickly, reducing precision debugging time.

What We Propose

We have already implemented a train–inference consistency data collection feature, and propose upstreaming it to slime in a parameter-controlled, default-off manner that does not affect the existing training path.

Request for Confirmation

Please confirm:

1. Whether “train–inference consistency data collection / comparison” is accepted as a complementary capability for slime.
2. If accepted, whether a default-off, flag-controlled, non-intrusive integration approach is acceptable.

If the direction is approved, we will follow up with a more detailed design and integration scope. We also welcome any constraints or guidance from the authors.

We would appreciate your reply at your earliest convenience. Thank you.
@zhuzilin

What I've Tried

We have already implemented a train–inference consistency data collection feature, and propose upstreaming it to slime in a parameter-controlled, default-off manner that does not affect the existing training path.

Environment (if relevant)

• slime version:
• Python version:
• PyTorch version:
• CUDA/ROCm version:
• GPU type and count:
• OS:

Additional Context

No response

Pre-submission Checklist

• I have read the CONTRIBUTING.md and understand the collaboration scope.
• I have read the documentation and FAQ and my question is not answered there.
• I have searched for existing issues and my question has not been asked before.

Start with CONTRIBUTING.md and the linked documentation and FAQ, then seek maintainer confirmation because the issue names no source files, tests, or entry points. The proposal requires a detailed design and integration scope before implementation. Done would mean an accepted, default-off, parameter-controlled capability that does not change the existing training path.