Sillage

Your language model forgets everything. Sillage gives it a memory — and a way to keep learning — in a fixed handful of megabytes, with no gradients and no index that grows.

sillage (n., French) — the trace left behind by something that has passed: a ship's wake, a scent in a room. What a model keeps of what it read.

A frozen language model reads your documents, remembers them, and predicts better next time. No gradients, no fine-tuning, no vector database. One Hebbian matrix written as the model reads, a semantic tier routed by confidence, a cold store that consolidates by surprise, and a rank-16 adapter on the readout — four mechanisms, four preprints, one command-line tool. Everything runs on a laptop CPU, and on a GPU when there is one.

Install

pip install sillage

Use

sillage index notes.md                # instant: no model, already queryable
sillage ask "what did the report say?"

sillage read notes.md                 # memorize it (CPU: ~8 min per 10k tokens)
sillage complete "The report said"    # generate WITH the memory
sillage status                        # what it knows, tier by tier
sillage chat                          # ask and generate in one session
sillage forget --all

$ sillage read preprint_v1.txt                    # Monday, memory empty
read preprint_v1.txt: 5859 tokens in 4.9 min | PPL 12.14 -> 11.83 (adapter) -> 11.71 (+memory)

$ sillage read preprint_v2.md                     # Tuesday, a new process
read preprint_v2.md: 11041 tokens in 9.5 min | PPL 10.68 -> 9.82 (adapter) -> 5.39 (+memory)

Three numbers per file: what the frozen model alone predicts, what the rank-16 adapter adds, and what the memory of everything read so far adds on top. The state lives in ./.sillage, survives restarts, and never grows: 7.4 MB with GPT-2, 25 MB with Qwen3, the same after one document or ten thousand. It never learns from its own generations — only from what you give it to read.

From Python:

from sillage import Sillage

s = Sillage(model="gpt2")          # any causal LM; omit it and the state
                                   # says which model it belongs to
s.read("notes.md")                 # read, memorize, index -- then save
s.ask("what did the report say?")  # exact passages, nothing generated
print(s.complete("The report said"))

How much better, exactly?

On 36k tokens of technical text the model had never seen (frozen GPT-2 124M, every system tuned identically on a held-out prefix, 95 % bootstrap CIs):

The fixed 4.2 MB memory beats the unbounded datastore it was designed to approximate — paired bootstrap P = 1.000, replicated over 5 random seeds and on a second model (Qwen3-0.6B).

Where it does not win: on long, low-repetition narrative text, kNN-LM still beats it. This memory captures verbatim recurrence; that is its regime, and it is measured and published rather than hidden.

Any causal language model, on CPU or GPU

sillage read notes.md --model qwen                          # shortcut
sillage read notes.md --model HuggingFaceTB/SmolLM2-135M    # any hub id
sillage read notes.md --model ./my-finetuned-llama          # any local folder
sillage read notes.md --device cuda                         # if you have one

Verified across three architectures (GPT-2, Qwen3, GPT-NeoX). Three things worth knowing before pointing it at a new model:

• The readout tunes itself. For a model nobody has tuned, it calibrates on a rolling window of what you read, following the papers' protocol: the winner governs the next read, never the one it was fitted on. For the two models the papers did tune, their published settings are kept — refitting those on a cold memory measurably loses (+0.109 against +0.120 nats).
• A memory lives in one model's token space. Give each model its own --state directory; the state remembers which model it belongs to and refuses to be opened by another.
• The GPU only does the frozen forward passes. --device cuda moves the model; the mechanisms stay in numpy on the CPU, where they belong — they are rank-1 updates, not matrix multiplications. Defaults to the GPU when there is one.

Requires Python 3.10+, numpy, torch and transformers. Nothing else, and no network at all once the frozen model is cached.

The four preprints

Sources, figures, every number as committed JSON, the reproduction pipeline and the three negative results are on GitHub: https://github.com/riscoss63/sillage

Citation

@article{sghairi2026sillage,
  title  = {Sillage: Surprise-Gated Amplitude Memory
            for Frozen Language Models},
  author = {Sghairi, Abderrahmane},
  year   = {2026},
  doi    = {10.5281/zenodo.22079016},
  url    = {https://doi.org/10.5281/zenodo.22079016}
}

MIT licensed.