Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/gmendonc/sleeper-mcp-server/claude-mdgit clone --depth 1 https://github.com/gmendonc/sleeper-mcp-serverWrote 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/gmendonc/sleeper-mcp-server/claude-md)<a href="https://agentmods.dev/instructions/gmendonc/sleeper-mcp-server/claude-md"><img src="https://agentmods.dev/badge/instructions/gmendonc/sleeper-mcp-server/claude-md.svg" alt="Measured on agentmods" 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 | $0.03691 | $0.03691 |
| Opus 5 | $0.01845 | $0.01845 |
| Sonnet 5 | $0.00738 | $0.00738 |
| Haiku 4.5 | $0.00369 | $0.00369 |
Grade A, and why
sleeper-mcp-server CLAUDE.md scanned grade A with 1 finding 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 4d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl "https://api.sleeper.app/v1/user/USERNAME" How it starts
The opening of the file, as written. The whole thing — 371 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md - Sleeper MCP Server Development Guide
This guide helps Claude Code understand and develop the Sleeper MCP Server, a TypeScript-based Model Context Protocol server that connects Claude Desktop to the Sleeper fantasy football API for intelligent multi-league management.
Project Philosophy and Goals
The Sleeper MCP Server exists to solve a specific problem: fantasy football players managing multiple leagues (typically 4-8) spend over three hours weekly on repetitive research and roster management. This project reduces that time to under one hour through AI-powered cross-league analysis.
The core philosophy is "Ship fast, iterate faster" - we prioritize working functionality that provides immediate value, then enhance based on actual usage patterns. The project uses AI-assisted development with Claude and GitHub Copilot, but architectural decisions remain human-driven to ensure user-centered design.
Understanding the Architecture
The Three-Layer Design
The project follows a clean three-layer architecture that separates concerns and makes the codebase maintainable:
Layer 1: API Client (sleeper-api.ts) This layer handles all communication with Sleeper's REST API. Think of it as a translator that speaks Sleeper's language. It includes intelligent caching to avoid overwhelming Sleeper's servers with redundant requests, which is crucial when analyzing multiple leagues simultaneously. The caching system stores responses for five minutes by default, dramatically improving performance for multi-league operations.
Layer 2: Business Logic (tools.ts) This is where the magic happens - raw API data gets transformed into meaningful insights. The tools layer takes information from multiple API calls, correlates it, enriches it with context, and formats it for human consumption. For example, when discovering leagues, it doesn't just list them - it calculates win percentages, identifies which leagues need attention, and sorts everything by relevance.
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.
- 4d ago First seen · 371 lines · 3,691 tokens per session scan A cf313af89f9f
sleeper-mcp-server CLAUDE.md is an instructions file published in the GitHub repository gmendonc/sleeper-mcp-server (2 stars, last pushed 11mo ago), licensed MIT. It adds 3,691 tokens to every session, about $0.0185 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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