meta-llama model fingerprint · v0.3.2

· Public eight-cell reference analysis

meta-llama/llama-3.1-70b-instruct behavioral LLM fingerprint

This page breaks down the exact reference that VerifyLLMAPI uses for meta-llama/llama-3.1-70b-instruct: 118 normalized answers across eight low-entropy probes, plus its nearest enrolled models by mean Jensen–Shannon divergence.

Fingerprint summary

Reference answers
118
Samples per cell
13–15
Nearest mean JSD
0.656458

The most concentrated cell was animal-random|en: kangaroo held 53.3% of its answers and entropy measured 1.990 bits. The broadest cell was letter-random|zh at 3.907 bits.

Against the closest enrolled model, letter-random|zh contributed the largest cell distance at JSD 0.908170. This is a descriptive comparison, not proof that either API route serves a named checkpoint.

Completeness: the author dataset allows up to 15 valid answers per selected cell in reference half A. This model contains 118/120 across the eight cells. We show the actual denominator for every share.

The eight test requests

The research pipeline sent each user prompt with a one-answer system constraint, temperature 1, a 16-token output cap, and reasoning disabled. VerifyLLMAPI uses the same prompt text and normalization target.

CellTaskExact request textNormalization and n
animal-random|en Random animal · English Name a random animal.
System constraintAnswer with a single word or a single number only. Output nothing else: no explanation, no punctuation, no quotation marks.
word · 15/15 reference samples
word-random|en Random word · English Name a random word.
System constraintAnswer with a single word or a single number only. Output nothing else: no explanation, no punctuation, no quotation marks.
word · 15/15 reference samples
animal-random|ru Random animal · Russian Назови случайное животное.
System constraintОтвечай только одним словом или одним числом. Не выводи ничего больше: без объяснений, без знаков препинания, без кавычек.
word · 15/15 reference samples
animal-random|ar Random animal · Arabic اذكر حيواناً عشوائياً.
System constraintأجب بكلمة واحدة أو رقم واحد فقط. لا تكتب أي شيء آخر: لا شرح ولا علامات ترقيم ولا علامات اقتباس.
word · 15/15 reference samples
letter-random|zh Random character · Chinese 说出一个随机的汉字。
System constraint只用一个词或一个数字回答。不要输出任何其他内容:不要解释,不要标点符号,不要引号。
grapheme · 15/15 reference samples
animal-random|zh Random animal · Chinese 说出一个随机的动物。
System constraint只用一个词或一个数字回答。不要输出任何其他内容:不要解释,不要标点符号,不要引号。
word · 15/15 reference samples
letter-random|ar Random letter · Arabic اذكر حرفاً عشوائياً من الحروف الأبجدية.
System constraintأجب بكلمة واحدة أو رقم واحد فقط. لا تكتب أي شيء آخر: لا شرح ولا علامات ترقيم ولا علامات اقتباس.
grapheme · 13/15 reference samples
color-random|zh Random color · Chinese 说出一个随机的颜色。
System constraint只用一个词或一个数字回答。不要输出任何其他内容:不要解释,不要标点符号,不要引号。
word · 15/15 reference samples

Response distributions

These are normalized reference-half counts from the published OpenRouter dataset. The tables contain aggregate values, not user data or a live VerifyLLMAPI scan.

1. animal-random|en

Random animal, English. 15 valid reference answers produced 6 normalized values. The mode was kangaroo at 8/15 (53.3%); entropy was 1.990 bits.

meta-llama/llama-3.1-70b-instruct response distribution for animal-random|en
Normalized responseCountShare
kangaroo 8 53.3%
rhinoceros 3 20.0%
koala 1 6.7%
leopard 1 6.7%
mongoose 1 6.7%
wolf 1 6.7%

2. word-random|en

Random word, English. 15 valid reference answers produced 9 normalized values. The mode was nebula at 5/15 (33.3%); entropy was 2.866 bits.

meta-llama/llama-3.1-70b-instruct response distribution for word-random|en
Normalized responseCountShare
nebula 5 33.3%
mango 2 13.3%
pineapple 2 13.3%
bicycle 1 6.7%
cloud 1 6.7%
corgi 1 6.7%
kangaroo 1 6.7%
paprika 1 6.7%
submarine 1 6.7%

3. animal-random|ru

Random animal, Russian. 15 valid reference answers produced 9 normalized values. The mode was лемур at 4/15 (26.7%); entropy was 2.974 bits.

meta-llama/llama-3.1-70b-instruct response distribution for animal-random|ru
Normalized responseCountShare
лемур 4 26.7%
енот 2 13.3%
крокодил 2 13.3%
лиса 2 13.3%
жираф 1 6.7%
леопард 1 6.7%
осьминог 1 6.7%
хомячок 1 6.7%
ягуар 1 6.7%

4. animal-random|ar

Random animal, Arabic. 15 valid reference answers produced 12 normalized values. The mode was الفيل at 2/15 (13.3%); entropy was 3.507 bits.

meta-llama/llama-3.1-70b-instruct response distribution for animal-random|ar
Normalized responseCountShare
الفيل 2 13.3%
فيل 2 13.3%
نمر 2 13.3%
الأرنب 1 6.7%
الببر 1 6.7%
التمساح 1 6.7%
الضبع 1 6.7%
القطة 1 6.7%
اليشعور 1 6.7%
دب 1 6.7%
ذئب 1 6.7%
زbra 1 6.7%

5. letter-random|zh

Random character, Chinese. 15 valid reference answers produced 15 normalized values. The mode was at 1/15 (6.7%); entropy was 3.907 bits.

meta-llama/llama-3.1-70b-instruct response distribution for letter-random|zh
Normalized responseCountShare
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%
1 6.7%

6. animal-random|zh

Random animal, Chinese. 15 valid reference answers produced 13 normalized values. The mode was 袋鼠 at 2/15 (13.3%); entropy was 3.640 bits.

meta-llama/llama-3.1-70b-instruct response distribution for animal-random|zh
Normalized responseCountShare
1 1 6.7%
14 1 6.7%
袋鼠 2 13.3%
2 13.3%
企鹅 1 6.7%
大象 1 6.7%
斑马 1 6.7%
狮子 1 6.7%
1 6.7%
蝙蝠 1 6.7%
蝴蝶 1 6.7%
鳄鱼 1 6.7%
鸵鸟 1 6.7%

7. letter-random|ar

Random letter, Arabic. 13 valid reference answers produced 10 normalized values. The mode was ت at 2/13 (15.4%); entropy was 3.239 bits.

meta-llama/llama-3.1-70b-instruct response distribution for letter-random|ar
Normalized responseCountShare
ت 2 15.4%
ح 2 15.4%
ك 2 15.4%
خ 1 7.7%
ر 1 7.7%
ش 1 7.7%
ص 1 7.7%
ط 1 7.7%
ق 1 7.7%
و 1 7.7%

8. color-random|zh

Random color, Chinese. 15 valid reference answers produced 8 normalized values. The mode was 紫色 at 6/15 (40.0%); entropy was 2.556 bits.

meta-llama/llama-3.1-70b-instruct response distribution for color-random|zh
Normalized responseCountShare
紫色 6 40.0%
粉色 3 20.0%
1 6.7%
绿 1 6.7%
蓝色 1 6.7%
1 6.7%
黄色 1 6.7%
黑色 1 6.7%

Three nearest enrolled references

We compute base-2 JSD for each of the eight categorical distributions, then average the eight distances. A lower value means more similar answer frequencies within this product reference. It does not identify an unknown route by itself.

RankReference modelMean 8-cell JSD
1 meta-llama/llama-3.3-70b-instruct 0.656458
2 meta-llama/llama-3.2-11b-vision-instruct 0.728754
3 openai/gpt-4o-mini-2024-07-18 0.744543

How many live requests does verification use?

ProfileCells × samplesFresh model requestsSame-data EER
Quick, default complete check4 × 52011.8%
Standard8 × 5408.1%
Paper budget8 × 151206.7%

The current-Agent workflow starts with quick. Each answer comes from a fresh Codex or Claude Code process that reuses host-managed login. These requests can consume host allowance or provider balance.

What this fingerprint can and cannot show

  • The reference records behavior observed through OpenRouter in the author dataset. Provider wrappers, model updates, decoding, and date can move a distribution.
  • The author collection set temperature 1 and disabled reasoning. Current-Agent mode labels sampling as a host default because supported Agent CLIs expose no temperature flag.
  • The eight high-gap cells and product thresholds use the same public cohort. Their EER values are calibration results, not an independent production accuracy claim.
  • A nearest reference is a similarity result. VerifyLLMAPI returns INCONCLUSIVE when the claimed route lacks an enrolled fingerprint.

Primary sources, license, and reproducibility

  1. Tomas Bruckner, One Token Is Enough: Fingerprinting and Verifying Large Language Models from Single-Token Output Distributions, arXiv:2607.10252v1.
  2. Author dataset and derived results, DOI 10.5281/zenodo.21278557, CC BY 4.0.
  3. Author collection and analysis software, DOI 10.5281/zenodo.21278793, MIT.
  4. VerifyLLMAPI atlas JSON, built from reference pamela-openrouter-2026-07-8cell-ref-a, SHA-256 51f3f63cbcfb56b151055d2d10e36a9cc2f0644cc68b580784853d68951fa866.

Page evidence SHA-256: 65bb4a97771f4051707a74eb08160c8fbcfd481257de4477368571fe67183be7. This hash covers the model ID, eight cell metrics, nearest references, and strongest cell difference in the generated atlas.

Run a current-Agent model check