Magic: The Gathering rules engine + online play platform, in Kotlin
Skill Claude CodeCodex
Implements new Magic: The Gathering cards for the Argentum Engine. Use when adding a new card, the user provides one or more card names to implement, or asks to implement a specific MTG card. Several cards that reuse existing primitives can be implemented together into one PR.
Skill Claude CodeCodex
Adds a new feature or mechanic to the Argentum Engine (SDK primitive, effect, trigger, condition, static/replacement ability, server/client capability) following the project's architecture and SDK-elegance principles. Use when implementing engine/SDK/server/client functionality that isn't a single card — e.g. "add an…
Skill Claude CodeCodex
Pick a random unimplemented card from a set and implement it. Accepts either a backlog cards.md path or a set name/code.
Skill Claude CodeCodex
Create professional, dark-themed architecture diagrams as standalone HTML files with SVG graphics. Use when the user asks for system architecture diagrams, infrastructure diagrams, cloud architecture visualizations, security diagrams, network topology diagrams, or any technical diagram showing system components and…
Skill Claude CodeCodex
Implement every "Assay-ready" card for a Magic set — the cards Argentum Assay reads whole that the set hasn't authored yet — placing each canonical in its earliest real printing and giving the sweep's own set a Printing row when the card is a reprint. Computes the four-way split first, authors to assay compile's JSON…
Skill Claude CodeCodex
Create the backlog/sets/ / entry for a Magic set — download the whole set from Scryfall (cached alongside Assay's cache), write cards.md as a per-colour checklist with the already-implemented cards ticked, scaffold the set's definitions/ / module if it doesn't exist, and write mechanics.md ordering every mechanic the…
Skill Claude CodeCodex
Generate a test scenario JSON for the DevScenarioController. Takes a description of what you want to test and produces a valid scenario file.
Skill Claude CodeCodex
Pick the next unchecked Bloomburrow card from the AI advisor checklist, evaluate if it needs an advisor, create one if needed, and check it off.
Skill Claude CodeCodex
Review pending changes (a branch, PR, or working tree) for the Argentum Engine. Optimizes for an elegant, reusable SDK — flags one-off effects/abilities that should compose existing primitives — and checks correctness, projection use, tests, and architectural fit. Use when the user says "review this PR", "review this…
Skill Claude CodeCodex
Launch a self-continuing agent loop that implements a whole MTG set, one reviewed PR at a time, using the harness's own loop primitive — Claude Code /loop, Codex /goal, or a plain repeat-until-done session. Composes the loop prompt with the set, the driving model id, and the PR labelling rule. Use when asked to…
Skill Claude CodeCodex
Prove a Magic set is actually finished — card-for-card complete, field-for-field faithful to Scryfall, scripts that match their oracle text, tokens that resolve the set's own art, behaviourally sound — then archive its backlog. Builds the Scryfall dump and CardFieldVerificationTest, fans the per-card DSL and token…
Skill Claude CodeCodex
Run the right build/test/lint gates for a change to the Argentum Engine and interpret the results — which suite to run, how to re-bless card snapshots, what a pre-existing failure means. Use before committing engine, SDK, card, or client changes, or when a build/test run needs interpreting.
At most 3 mods per repository are shown here, and a mod shipped inside a plugin is left to that plugin's page — the rest are on their repository pages: