SRT — Semiotic-Reflexive Transformer (Adapter Architecture)

Meaning forks. SRT sees it.

SRT-Adapter is a lightweight module that bolts semiotic awareness onto any frozen causal language model. The backbone runs natively — its own embeddings, its own LM head, its own attention. SRT modules are small taps that read divergence from hidden states, track reflexive awareness, and optionally inject semiotic corrections back into the stream.

Architecture

tokens ──► Backbone Embeddings (native, frozen)
               │
         ┌─────┴─────┐
         │  Layer 0-6 │  (frozen)
         └─────┬─────┘
               │
         ┌─────┴─────┐
  ┌─────►│  Layer 7   │──────► MAH₁ reads divergence ──► RRM step
  │      └─────┬─────┘
  │            │
  │      ┌─────┴─────┐
  │      │ Layer 8-13 │  (frozen)
  │      └─────┬─────┘
  │            │
  │      ┌─────┴─────┐
  ├─────►│  Layer 14  │──────► MAH₂ reads ──► RRM step ──► inject
  │      └─────┬─────┘                                       │
  │            │◄────────────────────────────────────────────┘
  │      ┌─────┴─────┐
  │      │ Layer 15-20│  (frozen, with semiotic correction)
  │      └─────┬─────┘
  │            │
  │      ┌─────┴─────┐
  └─────►│  Layer 21  │──────► MAH₃ reads ──► RRM step ──► inject
         └─────┬─────┘                                       │
               │◄────────────────────────────────────────────┘
         ┌─────┴─────┐
         │ Layer 22-27│  (frozen, with semiotic correction)
         └─────┬─────┘
               │
         Backbone LM Head (native, frozen) ──► logits + CE loss
               │
         BEN (from RRM meta-state) ──► r̂, regime, modulation

Key Ideas

1. Zero CE degradation — The backbone's native embeddings and LM head are untouched. Cross-entropy starts at pretrained quality (~3.5), not 200+.

2. ~14.6M trainable params — Only the semiotic modules train. The 7B backbone is fully frozen. Trains in hours, not weeks.

3. Unsupervised community discovery — A small encoder discovers discourse-trajectory structure from hidden state patterns. No hardcoded labels. As of v8a the encoder output is the community vector directly (continuous trajectory mode); earlier checkpoints used a 32-prototype soft-argmax readout that turned out to be a discriminability bottleneck (see paper.md §5.8–§5.9).

4. Backbone-agnostic — Works with any HuggingFace AutoModelForCausalLM: Qwen, LLaMA, Mistral, Phi, Gemma, etc.

5. Portable — Save/load just the 44MB adapter weights. Attach to any compatible backbone at inference time.

Modules

Quick Start

# install
git clone https://github.com/space-bacon/SRT.git
cd SRT
pip install -e .

Run inference (frozen Qwen-7B + released adapter)

from srt.adapter import SRTAdapter
from srt.config import build_config_from_json
from safetensors.torch import load_file
from huggingface_hub import hf_hub_download
from transformers import AutoTokenizer
import torch

repo = "RiverRider/srt-adapter-v1.0"          # or RiverRider/srt-adapter-v8a
cfg  = build_config_from_json(hf_hub_download(repo, "config.json"))
adap = SRTAdapter(cfg).cuda().eval()
adap.load_state_dict(load_file(hf_hub_download(repo, "adapter.safetensors")), strict=False)
tok  = AutoTokenizer.from_pretrained(cfg.backbone_id)

enc = tok("meaning forks here", return_tensors="pt").to("cuda")
with torch.no_grad():
    out = adap(input_ids=enc.input_ids, attention_mask=enc.attention_mask)
print(out.r_hat.mean().item(), out.community_output.encoded.shape)

See examples/ for end-to-end loading, scoring, and sentence-encoding scripts.

Live demos

• v1.0 demo: https://huggingface.co/spaces/RiverRider/srt-adapter-v1.0-demo
• v8a demo: https://huggingface.co/spaces/RiverRider/srt-adapter-v8a-demo

Train from scratch

python scripts/train.py \
    --backbone Qwen/Qwen2.5-7B \
    --train-data data/all_train.jsonl \
    --val-data   data/all_val.jsonl \
    --output-dir checkpoints/adapter_v1 \
    --batch-size 16 --epochs 3 --lr 3e-4 --max-val-samples 5000

Resume from a saved training_checkpoint.pt with --resume <path> (restores optimizer, scheduler, step, epoch).

Training Diagnostics

Every --log-every steps, the training script logs standard loss metrics plus semiotic diagnostics:

Red flags to watch for:

• div_norms → 0: divergence vectors collapsed, MAH not learning
• r_hat_std < 0.05: BEN stuck in trivial constant prediction
• inj_norms > 5: injection regularization not constraining norms (fixed in v3)
• CE climbing steadily: injections corrupting backbone representations
• Chain loss exactly 0.0: divergence collapsed to a constant

Checkpointing

The training script saves:

• training_checkpoint.pt — full state (adapter weights + optimizer + scheduler + step + epoch) at every validation step, for seamless resumption
• best_adapter.pt — adapter weights only, at best validation loss
• adapter_epoch{N}.pt — adapter weights at end of each epoch
• final_adapter.pt — adapter weights at end of training
• train_log.jsonl — all metrics + diagnostics in structured format

Theoretical Foundation

SRT is grounded in C.S. Peirce's semiotics. Language models process signs (representamens) but are blind to when meaning forks — when the same word means different things to different communities. SRT makes the model reflexively aware of its own semiotic processing:

• MAH implements metapragmatic awareness: detecting that "freedom" carries different interpretive weight in libertarian vs. socialist discourse.
• RRM implements reflexive recursion: the model's awareness of its own awareness, tracking how divergence propagates through the interpretant chain.
• BEN estimates the bifurcation point: where a sign tips from stable (subcritical) to contested (supercritical) interpretation.

See Lancaster (2025) — the full paper and arXiv source live in this repository (paper.md, paper.pdf, arxiv/).

Released checkpoints

Citation

@misc{lancaster2025srtadapter,
  title  = {The Semiotic-Reflexive Transformer Adapter: Lightweight Semiotic Awareness for Frozen Causal Language Models},
  author = {Lancaster, Burton},
  year   = {2025},
  url    = {https://github.com/space-bacon/SRT},
}

See CITATION.cff for machine-readable metadata.

License

Apache-2.0 — see LICENSE. The released adapter weights on Hugging Face are also Apache-2.0; the underlying Qwen/Qwen2.5-7B backbone is released under its own Qwen license, which applies whenever the backbone is loaded.