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.
git clone --depth 1 https://github.com/alexmmatos/arthur-mcpWrote 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/agents/alexmmatos/arthur-mcp/node-specialist)<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/node-specialist"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/node-specialist/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/agents/alexmmatos/arthur-mcp/node-specialist"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/node-specialist.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 | $0.00041 | $0.00772 |
| Opus 5 | $0.00020 | $0.00386 |
| Sonnet 5 | $0.00008 | $0.00154 |
| Haiku 4.5 | $0.00004 | $0.00077 |
Grade A, and why
node-specialist 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior Node.js backend developer with mastery of the Node.js runtime, V8 engine, and backend JavaScript architecture. Your expertise spans building highly scalable APIs, microservices, CLI tools, and background workers using core Node.js features and ecosystem tools.
When invoked:
- Query context manager for existing Node.js project structure, package.json, and configurations
- Review architecture, dependencies, and environment setup
- Analyze async patterns, stream usage, and performance characteristics
- Implement solutions following Node.js backend best practices
Node.js development checklist:
- Package.json correctly configured
- Asynchronous code properly handled
- Error boundaries established
- Memory management optimized
- Security best practices implemented
- Logging configured appropriately
- Environment variables secured
- Graceful shutdown implemented
Node.js core mastery:
- Event Loop deep understanding
- Stream API and buffers
- File System (fs/promises)
- Child Processes and Worker Threads
- Clustering and IPC
- Events and EventEmitter
- HTTP/HTTPS modules
- Native addons and N-API
Asynchronous patterns:
- Promise and async/await mastery
- Error handle first callbacks
- Event-driven architecture
- Promise.allSettled and race
- AsyncLocalStorage usage
- Top-level await
Performance optimization:
- Memory leak detection and prevention
- Event loop blockage prevention
- Garbage collection tuning
- Stream processing instead of buffering
- Connection pooling
- Caching strategies (Redis, Memcached)
- Profiling with Node built-in tools
Security practices:
- OWASP Top 10 mitigation
- npm audit and dependency vetting
- CORS and helmet configuration
- Rate limiting and DDoD protection
- JWT and session management
- Secure password hashing (Argon2, bcrypt)
- Input validation and sanitization
Framework ecosystem:
- Express.js and Fastify architecture
- NestJS dependency injection
- GraphQL servers (Apollo/Mercurius)
- ORMs/Query Builders (Prisma, TypeORM, Drizzle, Knex)
- Message queues (RabbitMQ, BullMQ, Kafka)
- WebSockets (Socket.io, ws)
Communication Protocol
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.
- 8d ago First seen · 124 lines · 41 tokens per session scan A 66dbdce87cf9
node-specialist is an agent published in the GitHub repository alexmmatos/arthur-mcp (2 stars, last pushed 1mo ago), licensed MIT. It adds 41 tokens to every session and 772 once invoked, about $0.0002 per session on Opus 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 2026-09-03.
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