Borrowing it
Nothing to install: this file belongs to gregario/mtg-oracle. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/gregario/mtg-oracle/main/CLAUDE.mdgit clone --depth 1 https://github.com/gregario/mtg-oracleWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/gregario/mtg-oracle/claude-md)<a href="https://agentmods.dev/instructions/gregario/mtg-oracle/claude-md"><img src="https://agentmods.dev/badge/instructions/gregario/mtg-oracle/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/gregario/mtg-oracle/claude-md"><img src="https://agentmods.dev/badge/instructions/gregario/mtg-oracle/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00271 | $0.00271 |
| Opus 5.5 | $0.00108 | $0.00108 |
| Sonnet 5.5 | $0.00054 | $0.00054 |
| Haiku 4.5 | $0.00027 | $0.00027 |
Grade A, and why
mtg-oracle CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
mtg-oracle
MCP server for Magic: The Gathering card data, rules, and deck analysis.
Stack Profiles
- MCP stack profile:
../../stacks/mcp/ - TypeScript stack profile:
../../stacks/typescript/
Read both stack profiles before writing any code.
Architecture
- Runtime data: Downloads Scryfall bulk data on first run, stores in
~/.mtg-oracle/ - Does NOT bundle card data in the npm package — data is fetched at runtime
- Updates: Checks Scryfall
bulk-datametadata endpoint, downloads only if newer - Storage: SQLite via
better-sqlite3for fast indexed queries
Data Source Compliance
Wizards of the Coast — Fan Content Policy
This project is unofficial Fan Content permitted under the Fan Content Policy. Not approved/endorsed by Wizards of the Coast. Portions of the materials used are property of Wizards of the Coast. All rights reserved.
Scryfall Terms
- Card data provided by Scryfall
- Must remain free to use
- Must add value beyond raw data access
- Do not claim endorsement by Scryfall
Engineering
Uses Superpowers for engineering execution. Follow TDD workflow: write tests first, then implement.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2mo ago First seen · 33 lines · 271 tokens per session scan A 5b5aeb241c64
mtg-oracle CLAUDE.md is an instructions file published in the GitHub repository gregario/mtg-oracle (5 stars, last pushed 6mo ago), licensed MIT. It adds 271 tokens to every session, about $0.0011 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
mtg-oracle CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| mtg-oracle CLAUDE.mdgregario/mtg-oracle | Instructions file | 5 | 6mo ago | MIT | A | 271 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | yesterday | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |