---
title: Speculative Decoding Trace
emoji: 🎯
colorFrom: blue
colorTo: green
sdk: static
app_file: index.html
pinned: false
license: mit
short_description: Watch rejection sampling accept/reject every draft token
---

# Speculative decoding, token by token

Two layers, both client-side (static Space — free tier, no ZeroGPU quota,
no cold starts):

1. **Interactive explainer** (`index.html`) — drag toy draft/target
   distributions and watch the acceptance probability min(1, p/q), the
   residual norm(max(p − q, 0)), the losslessness histogram, and the
   `E[tokens] = (1 − α^{γ+1})/(1 − α)` speedup curve respond live.
2. **Real inference in your browser** (`live.html`) — quantized ONNX
   `distilgpt2` drafts, `gpt2` verifies, via transformers.js
   (WebGPU/WASM). The actual rejection sampling on actual logits, with the
   per-position math rendered for every token.

The repo also ships a Gradio app with KV-cached speculative decoding,
draft-vs-target **attention-trace diffing**, and an optional 70B cloud
cross-check — run it locally with `python app.py`.

Source: https://github.com/aabhimittal/attention-trace-differ-for-speculative-decoding