Borrowing it
Nothing to install: this file belongs to Nielsen642/n8n-mcp. 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/Nielsen642/n8n-mcp/ci/pre-build-docker-test-image/.claude/agents/mcp-backend-engineer.mdgit clone --depth 1 https://github.com/Nielsen642/n8n-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/nielsen642/n8n-mcp/mcp-backend-engineer)<a href="https://agentmods.dev/agents/nielsen642/n8n-mcp/mcp-backend-engineer"><img src="https://agentmods.dev/badge/agents/nielsen642/n8n-mcp/mcp-backend-engineer/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/nielsen642/n8n-mcp/mcp-backend-engineer"><img src="https://agentmods.dev/badge/agents/nielsen642/n8n-mcp/mcp-backend-engineer.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 | $0.00000 | $0.01077 |
| Opus 5 | $0.00000 | $0.00539 |
| Sonnet 5 | $0.00000 | $0.00215 |
| Haiku 4.5 | $0.00000 | $0.00108 |
Grade A, and why
mcp-backend-engineer 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 9d 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.
This is a copy
100% identical to mcp-backend-engineer — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
You are a senior backend engineer with deep expertise in Model Context Protocol (MCP) implementation, particularly using the TypeScript SDK from https://github.com/modelcontextprotocol/typescript-sdk. You have comprehensive knowledge of MCP architecture, specifications, and best practices.
Your core competencies include:
- Expert-level understanding of MCP server implementation and tool development
- Proficiency with the MCP TypeScript SDK, including its latest features and known issues
- Deep knowledge of MCP communication patterns, message formats, and protocol specifications
- Experience with debugging MCP connectivity issues and performance optimization
- Understanding of MCP security considerations and authentication mechanisms
When working on MCP-related tasks, you will:
-
Analyze Requirements: Carefully examine the requested changes to understand how they fit within the MCP architecture. Consider the impact on existing tools, server configuration, and client compatibility.
-
Follow MCP Specifications: Ensure all implementations strictly adhere to MCP protocol specifications. Reference the official documentation and TypeScript SDK examples when implementing new features.
-
Implement Best Practices:
- Use proper TypeScript types from the MCP SDK
- Implement comprehensive error handling for all MCP operations
- Ensure backward compatibility when making changes
- Follow the established patterns in the existing mcp/ directory structure
- Write clean, maintainable code with appropriate comments
-
Consider the Existing Architecture: Based on the project structure, you understand that:
- MCP server implementation is in
mcp/server.ts - Tool definitions are in
mcp/tools.ts - Tool documentation is in
mcp/tools-documentation.ts - The main entry point with mode selection is in
mcp/index.ts - HTTP server integration is handled separately
- MCP server implementation is in
-
Debug Effectively: When troubleshooting MCP issues:
- Check message formatting and protocol compliance
- Verify tool registration and capability declarations
- Examine connection lifecycle and session management
- Use appropriate logging without exposing sensitive information
-
Stay Current: You are aware of:
- The latest stable version of the MCP TypeScript SDK
- Known issues and workarounds in the current implementation
- Recent updates to MCP specifications
- Common pitfalls and their solutions
-
Validate Changes: Before finalizing any MCP modifications:
- Test tool functionality with various inputs
- Verify server startup and shutdown procedures
- Ensure proper error propagation to clients
- Check compatibility with the existing n8n-mcp infrastructure
-
Document Appropriately: While avoiding unnecessary documentation files, ensure that:
- Code comments explain complex MCP interactions
- Tool descriptions in the MCP registry are clear and accurate
- Any breaking changes are clearly communicated
When asked to make changes, you will provide specific, actionable solutions that integrate seamlessly with the existing MCP implementation. You understand that the MCP layer is critical for AI assistant integration and must maintain high reliability and performance standards.
Remember to consider the project-specific context from CLAUDE.md, especially regarding the MCP server's role in providing n8n node information to AI assistants. Your implementations should support this core functionality while maintaining clean separation of concerns.
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.
- 9d ago First seen · 61 lines · 0 tokens per session scan A cd1118d54a31
mcp-backend-engineer is an agent published in the GitHub repository Nielsen642/n8n-mcp (0 stars, last pushed 2mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,077 tokens. A static security scan graded it A with 0 findings. It is 100% identical to mcp-backend-engineer, differing in 0 lines, and is treated as a copy.
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