# DeepSeek real-weight execution probes

The probes in this directory use official DeepSeek artifacts and keep their
scope deliberately narrower than a full-model benchmark.

## DeepSeek-V2-Lite truncated trace

`v2_lite_trace.py` executes layers 0–6 from the official BF16 checkpoint. Those
seven layers are fully contained in shard 1; layer 7 is split across shards 1
and 2 and is therefore outside the default evidence boundary.

Pinned model:

```text
deepseek-ai/DeepSeek-V2-Lite@604d5664dddd88a0433dbae533b7fe9472482de0
```

Required Python stack:

```text
torch==2.11.0+cu128
transformers==4.41.2
safetensors==0.8.0
```

The 2024 remote code does not import under Transformers 5.5 because
`is_torch_fx_available` was removed. The probe imports the official files as a
read-only local package; it does not patch the model source.

Download the metadata, tokenizer, remote code, index, and first shard with the
Hugging Face CLI, then run:

```bash
python experiments/deepseek/v2_lite_trace.py \
  --artifact-dir /path/to/deepseek-v2-lite \
  --output src/data/deepseek-v2-lite-trace.json
```

The result contains:

- real tokenizer pieces and model-derived hidden states;
- the actual `[B,T,576]` MLA compressed projection at each executed layer;
- the expanded key/value tensors stored by the Hugging Face eager cache;
- token-level top-6 routed expert IDs and weights for six MoE layers;
- per-layer and per-prompt expert-load summaries;
- explicit boundaries against global load, expert semantics, training traces,
  full-model generation, and production serving claims.

Run the probe twice and compare deterministic evidence while excluding timing:

```bash
python experiments/deepseek/compare_v2_lite_traces.py \
  --first /path/to/trace-1.json \
  --second /path/to/trace-2.json \
  --output src/data/deepseek-v2-lite-trace-repro.json
```

## Fixed public routing corpus

`v2_lite_routing_corpus.py` keeps the same official layer 0–6 execution boundary
but replaces the four authored prompts with 128 source-addressable public
prompts:

- 32 WikiText-2 raw validation passages;
- 32 CLUE TNEWS public-test sentences;
- 32 OpenAI HumanEval prompts, without solutions/tests or code execution;
- 32 OpenAI GSM8K test questions, without answers.

Selection is the ascending SHA-256 rank of a fixed salt, domain, and source ID.
Inputs are truncated to 96 DeepSeek tokens. The six MoE layers therefore produce
304,560 actual top-6 routed-expert selections over 8,460 valid tokens.

The output includes both token-weighted and prompt-balanced distributions. Its
95% intervals use 2,000 prompt-level bootstrap resamples within each domain,
rather than treating correlated tokens as independent observations.

```bash
PYTHONPATH=/path/to/transformers-4.41.2-deps \
python -B experiments/deepseek/v2_lite_routing_corpus.py \
  --artifact-dir /path/to/deepseek-v2-lite \
  --human-eval /path/to/HumanEval.jsonl.gz \
  --gsm8k /path/to/gsm8k/test.jsonl \
  --tnews /path/to/tnews/test.json \
  --tnews-archive /path/to/tnews_public.zip \
  --wikitext /path/to/wikitext-validation.parquet \
  --output src/data/deepseek-v2-lite-routing-corpus.json \
  --per-domain 32 \
  --max-tokens 96 \
  --batch-size 16 \
  --bootstrap 2000 \
  --seed 20260729 \
  --captured-at 2026-07-29T07:45:00+00:00
```

The committed independent rerun is byte-exact. Both JSON files have SHA-256:

```text
4678a1d15395de93ffba757598cc3642bf35e9e07f71d82ddd87c27fc38a09e4
```

See `research/DEEPSEEK_ROUTING_CORPUS_AUDIT.md` for corpus revisions and hashes,
metric definitions, interval semantics, results, and claim boundaries.

## Paired length-control cohort

The corpus runner can also select one fixed cohort by untruncated source length
and execute nested prefixes. The committed 16-token and 24-token traces use the
same 128 source prompts, all selected from records with at least 24 DeepSeek
tokens:

```bash
common_args=(
  --per-domain 32
  --batch-size 16
  --bootstrap 2000
  --sample-salt llm-atlas-deepseek-routing-length-control-v1
  --eligibility-min-tokens 24
)

python -B experiments/deepseek/v2_lite_routing_corpus.py \
  ...source arguments... \
  "${common_args[@]}" \
  --max-tokens 16 \
  --output src/data/deepseek-v2-lite-routing-matched16.json

python -B experiments/deepseek/v2_lite_routing_corpus.py \
  ...source arguments... \
  "${common_args[@]}" \
  --max-tokens 24 \
  --output src/data/deepseek-v2-lite-routing-matched24.json
```

The two real traces add 184,320 top-6 route selections. Their independent
reruns are byte-exact:

```text
matched-16  f8d437d5379ffb41ac8dca5a8e97c0f44ba10ce7b63f95d7be0b7c88ac0baebd
matched-24  bed54835ad243ca2ab46bf9574e53137e6c2c0e19267f581719b5f2f65546436
```

Use the paired comparison runner to resample identical prompt indices in the
short and long traces:

```bash
python -B experiments/deepseek/compare_routing_length_control.py \
  --short src/data/deepseek-v2-lite-routing-matched16.json \
  --long src/data/deepseek-v2-lite-routing-matched24.json \
  --output src/data/deepseek-v2-lite-routing-length-sensitivity.json \
  --bootstrap 2000 \
  --seed 20260729
```

See `research/DEEPSEEK_ROUTING_LENGTH_CONTROL_AUDIT.md` for the sampling bias
audit, paired CV/JSD deltas, total-variation accounting, and interpretation
boundaries.

## Official chat-template sensitivity

`v2_lite_routing_template_probe.py` renders three variants of one fixed
23-content-token prefix:

```text
raw         BOS + content
user        BOS + "User: " + content + "\n\n"
generation  user prefix + "Assistant:"
```

The latter two use the pinned official `chat_template` through
`apply_chat_template`. All three variants of one source prompt execute in the
same padded batch. Statistics are split between:

- the full operational input, including wrapper tokens;
- the exact intersection of `(relative character span, token ID)` inside the
  source content across all three variants.

The `user → generation` comparison is a causal negative control: the appended
suffix must not change routes on their shared prefix.

```bash
PYTHONPATH=/path/to/transformers-4.41.2-deps:/usr/lib/python3/dist-packages \
python -B experiments/deepseek/v2_lite_routing_template_probe.py \
  --artifact-dir /path/to/deepseek-v2-lite \
  --human-eval /path/to/HumanEval.jsonl.gz \
  --gsm8k /path/to/gsm8k/test.jsonl \
  --tnews /path/to/tnews/test.json \
  --tnews-archive /path/to/tnews_public.zip \
  --wikitext /path/to/wikitext-validation.parquet \
  --output src/data/deepseek-v2-lite-routing-template.json \
  --per-domain 32 \
  --content-tokens 23 \
  --batch-prompts 8 \
  --layers 7 \
  --bootstrap 2000 \
  --seed 20260729 \
  --captured-at 2026-07-29T08:30:00+00:00
```

The three variants add 382,032 real top-6 route selections. Across six MoE
layers, all 21,852 `user → generation` shared-prefix token routes are
ordered-top-6 exact. The committed run and independent rerun are byte-exact:

```text
da1f10333b2fa269e64f9716a0ca6c1a656d23d3e70b8a25d6e59f8a5b3bc1b9
```

See `research/DEEPSEEK_ROUTING_TEMPLATE_AUDIT.md` for the aligned-content
contract, paired intervals, per-token route stability, and claim boundaries.