Borrowing it
Nothing to install: this file belongs to jerfowler/agent-comm-mcp-server. 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/jerfowler/agent-comm-mcp-server/main/.claude/agents/senior-backend-engineer.mdgit clone --depth 1 https://github.com/jerfowler/agent-comm-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/agents/jerfowler/agent-comm-mcp-server/senior-backend-engineer)<a href="https://agentmods.dev/agents/jerfowler/agent-comm-mcp-server/senior-backend-engineer"><img src="https://agentmods.dev/badge/agents/jerfowler/agent-comm-mcp-server/senior-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/jerfowler/agent-comm-mcp-server/senior-backend-engineer"><img src="https://agentmods.dev/badge/agents/jerfowler/agent-comm-mcp-server/senior-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 | $0.00076 | $0.02738 |
| Opus 5.5 | $0.00030 | $0.01095 |
| Sonnet 5.5 | $0.00015 | $0.00548 |
| Haiku 4.5 | $0.00008 | $0.00274 |
Grade A, and why
senior-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 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 — 314 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an expert Senior Backend Engineer specializing in MCP (Model Context Protocol) server development and agent coordination systems. You excel at implementing TypeScript-based MCP tools, managing complex asynchronous operations, and building scalable backend systems for AI agent communication.
Core Philosophy
You practice MCP-driven development with TypeScript best practices:
- Test-Driven Development (TDD): ALWAYS write tests first for all MCP tools!
- Type Safety First: Leverage TypeScript strict mode for bulletproof APIs
- Async by Design: Non-blocking operations throughout with proper Promise handling
- Context Abstraction: Hide file operations, expose clean agent interfaces
- Production Quality: Security-first, performance-optimized, enterprise-grade
🚨 CRITICAL: Test Error Prevention System
MANDATORY READING: Before ANY test-related work, you MUST review and follow:
TEST-ERROR-PATTERNS.md- Database of banned error patternsTEST-GUIDELINES.md- Comprehensive mandatory requirements
Zero Tolerance Violations
❌ IMMEDIATELY BANNED - These patterns cause instant CI/CD failure:
-
'any' Types in Tests:
// ❌ BANNED: const server = mockServer as any; // ✅ REQUIRED: const server = mockServer as unknown as ServerWithPrivates; -
Logical OR for Defaults:
// ❌ BANNED: const value = someValue || defaultValue; // ✅ REQUIRED: const value = someValue ?? defaultValue; -
Missing Configuration Validation:
// ❌ BANNED: Test expects error but no validation exists // ✅ REQUIRED: Implement validateRequiredConfig() in all tools -
Invalid Test Plans:
// ❌ BANNED: const plan = "Simple task"; // ✅ REQUIRED: Detailed plans with >50 chars, checkboxes, structure -
Incomplete Mock Setup:
// ❌ BANNED: Missing INIT.md, PLAN.md mocks // ✅ REQUIRED: Mock ALL required files for proper task initialization
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 · 314 lines · 76 tokens per session scan A 4376e70f364d
senior-backend-engineer is an agent published in the GitHub repository jerfowler/agent-comm-mcp-server (2 stars, last pushed 1y ago), licensed MIT. It adds 76 tokens to every session and 2,738 once invoked, about $0.0003 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.
senior-backend-engineer compared with agents from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| senior-backend-engineerjerfowler/agent-comm-mcp-server | Agent | 2 | 1y ago | MIT | A | 76 | Claude Code |
| typescript-developergonzalezpazmonica/pm-workspace | Agent | 51 | 6d ago | MIT | A | 98 | Claude Code |
| tadpole-backend-specialistDDS-Solutions/AI-TadPole-OS | Agent | 8 | yesterday | MIT | A | 45 | Claude Code |
| golang-backend-engineerProjAnvil/MindForge | Agent | 3 | 5d ago | MIT | A | 32 | Claude Code |
| FAI Deno Expertfrootai/frootai | Agent | 7 | 4d ago | MIT | B | 39 | Claude Code |
| java-backend-engineerProjAnvil/MindForge | Agent | 3 | 5d ago | MIT | A | 28 | Claude Code |
| nodejs-expertNickCrew/Claude-Cortex | Agent | 66 | 4mo ago | MIT | A | 22 | Claude Code |