Cruncher Skill

Guides users through Crunch competition lifecycle: setup, quickstarter discovery, solution development, local testing, and submission.

Prerequisites

• Python 3.9+ with venv module (included in standard Python)
• pip for package installation

Package Installation

This skill installs Python packages from PyPI into isolated virtual environments:

Package	Source	Purpose
crunch-cli	PyPI	CrunchDAO competition CLI (setup, test, submit)
jupyter	PyPI	Notebook support (optional)
ipykernel	PyPI	Jupyter kernel registration (optional)
Competition SDKs (e.g. crunch-synth, birdgame)	PyPI	Competition-specific libraries (varies)

Agent rules for package installation:

• Always use a virtual environment — never install into system Python
• Only install known packages listed above or referenced in competition docs (PACKAGES.md)
• Ask the user before installing any package not listed here
• All packages are from PyPI — no custom URLs, no --index-url overrides, no .whl files from unknown sources

Credentials

Submission Token (required for setup & submit)

• How to get: User logs into CrunchDAO Hub, navigates to the competition's submit page (/competitions/<competition>/submit), and copies their token
• How it's used: Passed once via --token <TOKEN> during crunch setup
• Persistence: After setup, the CLI stores the token in the project's .crunch/ config directory. All subsequent commands (crunch test, crunch push, crunch download) authenticate automatically — no need to pass the token again
• If token expires: Run crunch update-token inside the project directory to refresh it

Agent rules for tokens:

• Always ask the user to provide the token — never assume, guess, or reuse tokens from other projects
• Never write tokens into source files, scripts, notebooks, or any committed file
• Never log or echo tokens in shell output (use --token <TOKEN> placeholder in examples shown to user)
• Tokens are user-specific and project-scoped — each crunch setup call requires the user to supply one

GitHub API (optional, unauthenticated)

• Used only for browsing quickstarter listings via api.github.com (public repo, no auth needed)
• Rate-limited to 60 requests/hour per IP; sufficient for normal use

Network Access

Operation	Requires network	Endpoint
crunch setup	Yes	hub.crunchdao.com
crunch push	Yes	hub.crunchdao.com
crunch download	Yes	hub.crunchdao.com
crunch test	No	Local only
crunch list	Yes	hub.crunchdao.com
pip install	Yes	pypi.org
Quickstarter browsing	Yes	api.github.com

Quick Setup

Each competition needs its own virtual environment (dependencies can conflict).

mkdir -p ~/.crunch/workspace/competitions/<competition>
cd ~/.crunch/workspace/competitions/<competition>
python -m venv .venv && source .venv/bin/activate 
pip install crunch-cli jupyter ipykernel --upgrade --quiet --progress-bar=off
python -m ipykernel install --user --name <competition> --display-name "Crunch - <competition>"

# Get token from: https://hub.crunchdao.com/competitions/<competition>/submit
crunch setup <competition> <project-name> --token <TOKEN>
cd <competition>-<project-name>

For competition-specific packages and full examples, see references/competition-setup.md.

Core Workflow

1. Discover

crunch list                    # List competitions

2. Explain

Read the quickstarter code (main.py or notebook) and competition's SKILL.md/README.md. Provide walkthrough covering: Goal, Interface, Data flow, Approach, Scoring, Constraints, Limitations, Improvement ideas.

3. Propose Improvements

Analyze current approach, cross-reference competition docs (SKILL.md, LITERATURE.md, PACKAGES.md), generate concrete code suggestions:

• Model: mixture densities, NGBoost, quantile regression, ensembles
• Features: volatility regimes, cross-asset correlation, seasonality
• Architecture: online learning, Bayesian updating, horizon-specific models

4. Test

crunch test                    # Test solution locally

5. Submit

crunch test                    # Always test first
crunch push -m "Description"   # Submit

Phrase Mapping

User says	Action
what competitions are available	crunch list
show quickstarters for <name>	Fetch from GitHub API
set up <competition>	Full workspace setup
download the data	crunch download
get the <name> quickstarter	crunch quickstarter --name
explain this quickstarter	Structured code walkthrough
propose improvements	Analyze and suggest code improvements
test my solution	crunch test
compare with baseline	Run both, side-by-side results
submit my solution	crunch push

Important Rules

• Entrypoint must be main.py (default for crunch push/crunch test)
• Model files go in resources/ directory
• Respect competition interface and constraints (time limits, output format)
• Ask before installing new packages

Reference

• CLI commands: references/cli-reference.md
• Setup examples: references/competition-setup.md