{
  "notes": "Token-weighted pretraining mixture read by scripts/pretrain_mix.py (iter_mixture). Weights are relative among enabled components; a component stops once it has contributed max_epochs passes over its train tokens, and the others fill the rest. Token counts are exact for the selected tokenizer (token_counts_dir, written by scripts/tokenizer_build.py count). Eval data never enters the mixture: gpio_actions is rendered from the train split only.",
  "target_tokens": 550000000,
  "target_note": "About 27 tokens per parameter for the recommended ~20M-parameter model; within the ~4 passes over repeated data that data-constrained scaling results show cost little (Muennighoff et al., 2023).",
  "seed": 20260914,
  "shuffle_buffer": 10000,
  "token_counts_dir": "data/tokenized/counts/gpio_llm_bpe_12k",
  "components": [
    {
      "name": "fineweb_edu_dedup",
      "enabled": true,
      "kind": "manifest",
      "manifest": "data/sources/english/fineweb_edu_dedup.json",
      "weight": 0.6,
      "max_epochs": 3.5,
      "role": "General English (docs/ENGLISH_DATASETS.md #1). Up to 3.5 passes; data-constrained scaling results show little loss from up to about 4 epochs of repetition."
    },
    {
      "name": "gpio_actions",
      "enabled": true,
      "kind": "jsonl",
      "render_from": "data/splits/train.jsonl",
      "files": {
        "train": [
          "data/cleaned/english/gpio_actions/train.jsonl"
        ]
      },
      "weight": 0.03,
      "max_epochs": 6,
      "role": "This project's validated GPIO examples as plain text (train split only), capped at 6 passes; the action behaviour itself is taught in fine-tuning."
    },
    {
      "name": "tinystories_v2",
      "enabled": false,
      "kind": "manifest",
      "manifest": "data/sources/english/tinystories_v2.json",
      "weight": 0.12,
      "max_epochs": 1.0,
      "role": "Recommendation #4, not downloaded yet."
    },
    {
      "name": "electronics_stackexchange",
      "enabled": false,
      "kind": "manifest",
      "manifest": "data/sources/english/electronics_stackexchange.json",
      "weight": 0.08,
      "max_epochs": 1.0,
      "role": "Recommendation #5, not downloaded yet (CC BY-SA)."
    }
  ]
}