Hugging Face published a five-step curriculum for post-training agents, from SFT on traces through to RL on real agent runs
AspireAI community · Hugging Face blog
The curriculum lays out agentic post-training as an ordered sequence, each stage with its own diagram, livestream, blog post and documentation: SFT on agent traces from a stronger model, then distillation from a teacher's tokens or probabilities, then RL with a reward per answer, then RL environments where the reward is the outcome of acting, and finally harnesses and scale with AsyncGRPOTrainer on full runs of a real agent. Each step names the TRL trainer to use and what you need to prepare, with a coding agent as the running example. The honest limit: it is a guided path rather than a result, and it is the SFT-first ordering that most teams skip.
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Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.