Building a Stable Fable 5 Traces Workflow in Colab: Parsing Tool Calls, Auditing Data, and Training Baselines

In this tutorial, we work with the Fable 5 Traces dataset from Hugging Face and build a complete workflow around real coding-agent trace data. We start by setting up a lightweight environment that avoids fragile dependencies such as datasets, scikit-learn, and scipy. Then we manually download and parse the merged JSONL file to keep the notebook stable in Colab. From there, we inspect repository files, preview raw trace examples, normalize tool calls and text outputs, audit the dataset structure, detect potential secret-like patterns, and visualize key distributions, including output types, tools, source roots, and text lengths. We also create safe no-CoT chat/SFT exports, build a simple keyword-search helper, and train pure-Python Naive Bayes baselines to assess whether trace context can predict the assistant’s output type and tool usage.

Setting Up the Fable 5 Traces Colab Environment and Helpers

import os

import sys

import json