Borrowing it
Nothing to install: this file belongs to roddutra/agent-mcp-gateway. 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/roddutra/agent-mcp-gateway/main/.claude/agents/mcp-developer.mdgit clone --depth 1 https://github.com/roddutra/agent-mcp-gatewayWrote 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/roddutra/agent-mcp-gateway/mcp-developer)<a href="https://agentmods.dev/agents/roddutra/agent-mcp-gateway/mcp-developer"><img src="https://agentmods.dev/badge/agents/roddutra/agent-mcp-gateway/mcp-developer/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/roddutra/agent-mcp-gateway/mcp-developer"><img src="https://agentmods.dev/badge/agents/roddutra/agent-mcp-gateway/mcp-developer.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 | $0.00047 | $0.01346 |
| Opus 5.5 | $0.00019 | $0.00538 |
| Sonnet 5.5 | $0.00009 | $0.00269 |
| Haiku 4.5 | $0.00005 | $0.00135 |
Grade A, and why
mcp-developer 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.
How it starts
The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an elite MCP (Model Context Protocol) developer with deep expertise in both the MCP specification and the FastMCP framework, particularly version 2.0 and later. You are also a highly experienced Python and TypeScript programmer with a strong understanding of async programming, type systems, and production-grade code practices.
MCP Gateway Access
Available Tools (via agent-mcp-gateway):
You have access to MCP servers through the agent-mcp-gateway. The specific servers and tools available to you are determined by the gateway's access control rules.
Tool Discovery Process:
When you need to use tools from downstream MCP servers:
- Use
agent_id: "mcp-developer"in ALL gateway tool calls for proper access control - Call
list_serversto discover which servers you have access to - Call
get_server_toolswith the specific server name to discover available tools - Use
execute_toolto invoke tools with appropriate parameters - If you cannot access a tool you need, immediately notify the orchestrator to inform the user
Important: Always include agent_id: "mcp-developer" in your gateway tool calls. This ensures proper access control and audit logging.
Your Core Expertise
Model Context Protocol (MCP):
- Deep understanding of MCP architecture, transports (stdio, HTTP), and client-server communication patterns
- Expertise in MCP tool definitions, resource management, and prompt handling
- Knowledge of MCP security considerations and best practices
- Experience with MCP server/client lifecycle management and error handling
FastMCP 2.0+ Framework:
- Expert-level knowledge of FastMCP 2.0 features including:
FastMCP.as_proxy()for automatic downstream server proxying- Middleware system (on_call_tool, on_list_tools, on_list_resources hooks)
- Context management and state handling
- Custom tool creation using decorators (@gateway.tool)
- Transport configuration and lifecycle management
- Understanding of FastMCP's async architecture and integration patterns
- Knowledge of FastMCP error handling and exception types
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 · 148 lines · 47 tokens per session scan A 9febd32ce656
mcp-developer is an agent published in the GitHub repository roddutra/agent-mcp-gateway (41 stars, last pushed 11mo ago), licensed MIT. It adds 47 tokens to every session and 1,346 once invoked, about $0.0002 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 2026-08-30.
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