🃏 MTG Python Deckbuilder

A web-first Commander/EDH deckbuilder with a shared core for CLI, headless, and Docker workflows. It builds curated decks, enforces bracket policies, understands owned cards, and ships a modern FastAPI + HTMX UI.

• Web UI priority: All homepage actions map to the sections below.
• Shared logic: Web, CLI, and headless runs use the same builder engine and exports.
• Deterministic outputs: Random modes respect seeds, include/exclude lists, and bracket rules.
• Data-aware UX: Owned library, themes, commanders, diagnostics, and logs live side-by-side.

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Table of contents

• Quick start
• Homepage guide
  • Build a Deck
  • Run a JSON Config
  • Initial Setup
  • Owned Library
  • Browse Commanders
  • Browse Themes
  • Finished Decks
  • Random Build
  • Diagnostics
  • View Logs
• CLI & headless flows
• Data, exports, and volumes
• Environment variables
• Project layout
• Development setup
• Troubleshooting
• Contributing
• License & attribution
• Further reading

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Quick start

Pick the path that fits your setup. All commands target Windows PowerShell.

Option 1 — Docker Compose (recommended web experience)

docker compose up --build --no-deps -d web

The Web UI starts on http://localhost:8080. First boot seeds data, refreshes decks, and tags cards automatically (see env defaults in docker-compose.yml). Use docker compose stop web / docker compose start web to pause or resume.

Option 2 — Docker Hub image

docker run --rm -p 8080:8080 `
  -v "${PWD}/deck_files:/app/deck_files" `
  -v "${PWD}/logs:/app/logs" `
  -v "${PWD}/csv_files:/app/csv_files" `
  -v "${PWD}/config:/app/config" `
  -v "${PWD}/owned_cards:/app/owned_cards" `
  mwisnowski/mtg-python-deckbuilder:latest

Brings up the same web UI using the prebuilt image. All volumes persist on the host.

Option 3 — Run from source

python -m venv .venv
.\venv\Scripts\Activate.ps1
pip install -r requirements.txt
uvicorn code.web.app:app --host 127.0.0.1 --port 8080

CLI entry point: python code/main.py. Headless convenience runner: python code/headless_runner.py --config config/deck.json.

For deeper Docker notes (including headless runs, impersonating CLI via compose, and maintenance scripts) see DOCKER.md.

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Homepage guide

Every tile on the homepage connects to a workflow. Use these sections as your tour.

Build a Deck

Start here for interactive deck creation.

• Pick commander, themes (primary/secondary/tertiary), bracket, and optional deck name in the unified modal.
• Add supplemental themes in the Additional Themes section (ENABLE_CUSTOM_THEMES): fuzzy suggestions, removable chips, and strict/permissive matching toggles respect THEME_MATCH_MODE and USER_THEME_LIMIT.
• Locks, Replace, Compare, and Permalinks live in Step 5.
• Exports (CSV, TXT, compliance JSON, summary JSON) land in deck_files/ and reuse your chosen deck name when set.
• ALLOW_MUST_HAVES=1 (default) enables include/exclude enforcement.
• WEB_AUTO_ENFORCE=1 re-runs bracket enforcement automatically after each build.

Run a JSON Config

Execute saved configs without manual input.

• Place JSON configs under config/ (see config/deck.json for a template).
• Launch via homepage button or by running the container with APP_MODE=cli and DECK_MODE=headless.
• Respect include/exclude, owned, and theme overrides defined in the config file or env vars.
• Supplemental themes: add "additional_themes": ["Theme A", "Theme B"] plus "theme_match_mode": "permissive"|"strict". Strict mode stops the build when a theme cannot be resolved; permissive keeps going and prints suggestions. Exported configs also include a camelCase alias ("userThemes") and the active catalog version ("themeCatalogVersion"); either field name is accepted on import.

Initial Setup

Refresh data and caches when formats shift.

• Runs card downloads, CSV regeneration, tagging, and commander catalog rebuilds.
• Controlled by SHOW_SETUP=1 (on by default in compose).
• Force a rebuild manually:

  docker compose run --rm --entrypoint bash web -lc "python -m code.file_setup.setup"
  

• Rebuild only the commander catalog:

  docker compose run --rm --entrypoint bash web -lc "python -m code.scripts.refresh_commander_catalog"
  

Owned Library

Keep track of cards you own.

• Upload .txt or .csv lists; the app enriches and deduplicates entries.
• Owned-only and Prefer-owned build modes live in the New Deck modal.
• owned_cards/ is persisted via volume mounting (OWNED_CARDS_DIR=/app/owned_cards).
• Enable virtualization for large libraries with WEB_VIRTUALIZE=1.

Browse Commanders

Explore the curated commander catalog.

• Powered by csv_files/commander_cards.csv.
• Toggle the tile with SHOW_COMMANDERS=1.
• Refresh via Initial Setup or the commander catalog script above.
• MDFC merges and compatibility snapshots are handled automatically; use --compat-snapshot on the refresh script to emit an unmerged snapshot.

Browse Themes

Investigate theme synergies and diagnostics.

• ENABLE_THEMES=1 keeps the tile visible (default).
• Extra tooling (/themes/metrics, uncapped synergies, editorial quality) is gated by WEB_THEME_PICKER_DIAGNOSTICS=1.
• Rebuild the merged catalog as needed:

  docker compose run --rm --entrypoint bash web -lc "python -m code.scripts.build_theme_catalog"
  

• Generate the normalized supplemental theme catalog (commander & card counts) for user-added themes:

  python -m code.scripts.generate_theme_catalog --output config/themes/theme_catalog.csv
  

  Add --logs-dir logs/generated to mirror the CSV for diffing, or --csv-dir to point at alternate datasets.
• Advanced editorial knobs (EDITORIAL_*, SPLASH_ADAPTIVE, etc.) live in .env.example and are summarized in the env table below.

Finished Decks

Review, compare, and export previous builds.

• Reads from the deck_files/ volume.
• Compare view can diff two builds, copy summaries, and download text lists.
• Locks, replace history, and compliance metadata persist per deck.

Random Build

Spin up surprise decks with deterministic fallbacks.

• Enable backend endpoints with RANDOM_MODES=1 and the UI tile with RANDOM_UI=1.
• Fine-tune with RANDOM_MAX_ATTEMPTS, RANDOM_TIMEOUT_MS, RANDOM_PRIMARY_THEME, RANDOM_SEED, and RANDOM_AUTO_FILL.
• Random flows honor include/exclude lists, owned filters, and bracket enforcement.

Diagnostics

Peek at health & performance.

• Enabled via SHOW_DIAGNOSTICS=1.
• /diagnostics summarizes system status, feature flags, and theme metrics.
• /healthz offers a lightweight probe ({status, version, uptime_seconds}).
• Press v inside virtualized lists (when WEB_VIRTUALIZE=1) to view grid diagnostics.

View Logs

Tail and download logs without leaving the browser.

• Enabled via SHOW_LOGS=1.
• /logs shows recent entries, filtering, and copy-to-clipboard.
• Raw files live under the mounted logs/ directory.
• /status/logs?tail=N returns JSON payloads for automation.

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CLI & headless flows

The CLI and headless runners share the builder core.

• Launch menu-driven CLI: python code/main.py.
• Run headless (non-interactive) builds: python code/headless_runner.py --config config/deck.json.
• In Docker, set APP_MODE=cli (and optionally DECK_MODE=headless) to switch the container entrypoint to the CLI.
• Config precedence is CLI prompts > environment variables > JSON config > defaults.

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Data, exports, and volumes

Host path	Container path	Purpose
deck_files/	/app/deck_files	CSV/TXT exports, compliance JSON, summary JSON
logs/	/app/logs	Application logs, taxonomy snapshots
csv_files/	/app/csv_files	Card datasets, commander catalog, tagging metadata
config/	/app/config	JSON configs, bracket policies, themes, card lists
owned_cards/	/app/owned_cards	Uploaded owned-card libraries

Exports follow a stable naming scheme and include a .summary.json sidecar containing deck metadata, resolved themes, and lock history.

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Environment variables

Most defaults are defined in docker-compose.yml and documented in .env.example. Highlights:

Core modes & networking

Variable	Default	Purpose
APP_MODE	web	Switch between Web UI (web) and CLI (cli).
DECK_MODE	(unset)	headless auto-runs the builder in CLI mode.
DECK_CONFIG	/app/config/deck.json	Points the headless runner at a config file or folder.
HOST / PORT / WORKERS	0.0.0.0 / 8080 / 1	Uvicorn settings for the web server.

Homepage visibility & UX

Variable	Default	Purpose
SHOW_SETUP	1	Show the Initial Setup tile.
SHOW_LOGS	1	Enable the logs viewer tile and endpoints.
SHOW_DIAGNOSTICS	1	Unlock diagnostics views and overlays.
SHOW_COMMANDERS	1	Enable the commander browser.
ENABLE_THEMES	1	Keep the theme browser and selector active.
ENABLE_CUSTOM_THEMES	1	Surface the Additional Themes section in the New Deck modal.
WEB_VIRTUALIZE	1	Opt into virtualized lists for large datasets.
ALLOW_MUST_HAVES	1	Enforce include/exclude (must-have) lists.
THEME	dark	Default UI theme (system, light, or dark).

Random build tuning

Variable	Default	Purpose
RANDOM_MODES	(unset)	Expose random build endpoints.
RANDOM_UI	(unset)	Show the Random Build homepage tile.
RANDOM_MAX_ATTEMPTS	5	Retry budget when constraints are tight.
RANDOM_TIMEOUT_MS	5000	Per-attempt timeout in milliseconds.
RANDOM_REROLL_THROTTLE_MS	350	Minimum milliseconds between reroll requests (client-side guard).
RANDOM_STRUCTURED_LOGS	0	Emit structured JSON logs for random builds.
RANDOM_TELEMETRY	0	Enable lightweight timing/attempt metrics for diagnostics.
RANDOM_PRIMARY_THEME / RANDOM_SECONDARY_THEME / RANDOM_TERTIARY_THEME	(blank)	Override selected themes.
RANDOM_SEED	(blank)	Deterministic seed for reproducible builds.
RANDOM_AUTO_FILL	1	Allow auto-fill of missing theme slots.

Random rate limiting (optional)

Variable	Default	Purpose
RATE_LIMIT_ENABLED	0	Enable server-side rate limiting for random endpoints.
RATE_LIMIT_WINDOW_S	10	Rolling window size in seconds.
RATE_LIMIT_RANDOM	10	Max random attempts per window.
RATE_LIMIT_BUILD	10	Max full builds per window.
RATE_LIMIT_SUGGEST	30	Max suggestion calls per window.

Automation & performance

Variable	Default	Purpose
WEB_AUTO_SETUP	1	Auto-run setup when artifacts are missing or stale.
WEB_AUTO_REFRESH_DAYS	7	Refresh cards.csv if older than N days.
WEB_TAG_PARALLEL	1	Enable parallel tagging workers.
WEB_TAG_WORKERS	4	Worker count for tagging (compose default).
WEB_AUTO_ENFORCE	0	Auto-apply bracket enforcement after builds.
WEB_THEME_PICKER_DIAGNOSTICS	1	Enable theme diagnostics endpoints.

Paths & overrides

Variable	Default	Purpose
CSV_FILES_DIR	/app/csv_files	Alternate dataset location (useful for tests).
DECK_EXPORTS	/app/deck_files	Override where exports land.
OWNED_CARDS_DIR / CARD_LIBRARY_DIR	/app/owned_cards	Override owned library path.
CARD_INDEX_EXTRA_CSV	(blank)	Inject extra CSV data into the card index.

Supplemental themes

Variable	Default	Purpose
DECK_ADDITIONAL_THEMES	(blank)	Comma/semicolon separated list of supplemental themes to apply in headless builds.
THEME_MATCH_MODE	permissive	Controls fuzzy resolution strictness (strict blocks unresolved themes) and seeds the web UI default.
USER_THEME_LIMIT	8	Maximum number of user-supplied themes allowed in the web builder.

Refer to .env.example for advanced editorial, taxonomy, and experimentation knobs (EDITORIAL_*, SPLASH_ADAPTIVE, WEB_THEME_FILTER_PREWARM, etc.). Document any newly introduced variables in the README, DOCKER guide, compose files, and .env.example.

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Project layout

code/                 FastAPI app, deckbuilding engine, CLI, scripts, and tests
├─ web/               Web UI (FastAPI + Jinja2 + HTMX)
├─ deck_builder/      Core builder logic and services
├─ tagging/           Tag pipelines and utilities
├─ locks/             Card locking utilities
├─ scripts/           Maintenance and editorial tools
├─ tests/             Pytest suite (web, CLI, random, tagging)
config/               JSON configs, bracket policies, themes, card lists
csv_files/            Card datasets, commander catalog, theme outputs
owned_cards/          User-supplied owned lists
logs/                 Application logs and taxonomy snapshots
deck_files/           Generated deck exports (CSV/TXT/JSON)

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Development setup

1. Create and activate the virtual environment:

   python -m venv .venv
   .\venv\Scripts\Activate.ps1
   

2. Install dependencies:

   pip install -r requirements.txt -r requirements-dev.txt
   

3. Run the web app locally:

   uvicorn code.web.app:app --host 127.0.0.1 --port 8080
   

4. Run tests (prefer targeted files—no wildcards):

   C:/Users/Matt/mtg_python/mtg_python_deckbuilder/.venv/Scripts/python.exe -m pytest -q code/tests/test_random_determinism.py code/tests/test_permalinks_and_locks.py
   

   Use tasks.json entries such as pytest-fast-random or pytest-fast-locks for quick feedback.
5. Linting and type checks follow pyproject.toml / mypy.ini defaults. Keep changes minimal and well-typed.

When adding features, favor the web UI first, keep public builder APIs stable, and update documentation (CHANGELOG → RELEASE_NOTES_TEMPLATE → DOCKER → README) in that order.

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Troubleshooting

• Blank page after start: Visit /healthz, check /logs, ensure SHOW_LOGS=1, and inspect host logs/ for stack traces.
• Stale data: Run Initial Setup or delete csv_files/.tagging_complete.json to force reseeding.
• Owned-only build fails: Confirm owned files were uploaded correctly and that owned_cards/ is mounted.
• Random build stalls: Lower RANDOM_MAX_ATTEMPTS, increase RANDOM_TIMEOUT_MS, and verify selected themes exist via /themes/.
• Commander list outdated: Rerun the commander refresh script or Initial Setup.

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Contributing

Pull requests are welcome—follow the conventional commit style, keep diffs focused, add or update tests when behavior changes, and document new env vars or workflows. Review CONTRIBUTING_EDITORIAL.md for editorial tooling guidance.

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License & attribution

Licensed under the MIT License. Card data and imagery are provided by Scryfall; please respect their API terms.

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Further reading

• Web UI deep dive – advanced Stage 5 tooling, multi-copy packages, virtualization tips, and diagnostics overlays.
• Theme catalog advanced guide – API endpoints, governance policies, editorial tooling, and validation scripts.
• Headless & CLI guide – automation entry points, environment overrides, and argument walkthroughs.
• Commander catalog handbook – required columns, refresh workflow, and staging toggles.
• Random theme exclusions reference – curation guidance for curated pools.
• Theme taxonomy rationale – roadmap and philosophy behind theme governance.