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 agents/0xfurai/claude-code-subagents/express-expertgit clone --depth 1 https://github.com/0xfurai/claude-code-subagentsWrote 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/0xfurai/claude-code-subagents/express-expert)<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/express-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/express-expert.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 | $0.00017 | $0.00367 |
| Opus 5 | $0.00009 | $0.00183 |
| Sonnet 5 | $0.00003 | $0.00073 |
| Haiku 4.5 | $0.00002 | $0.00037 |
Grade A, and why
express-expert 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 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.
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.
What it actually says
Focus Areas
- Middleware design and pipeline management
- Route handling and parameter parsing
- Error handling and custom error pages
- Security best practices with Express
- Middleware for logging and auditing requests
- Static asset delivery and caching
- Application configuration and environment management
- Authentication and authorization mechanisms
- Session management and cookie handling
- Request validation and sanitation
Approach
- Use a structured project layout for maintainability
- Implement middleware for cross-cutting concerns
- Utilize async/await for asynchronous operations
- Centralize configuration with environment variables
- Implement robust error handling middleware
- Leverage Express Router for modular route management
- Use Helmet for setting security headers
- Optimize performance with compression and caching
- Implement a logging strategy with Winston or Morgan
- Keep dependencies up to date and minimal
Quality Checklist
- Adherence to Express best practices
- Routes are RESTful and consistent
- All middleware are error-free and performant
- Security headers are correctly set
- Errors are handled gracefully and consistently
- Logging provides necessary request and error details
- Environment configuration is flexible and complete
- Authentication and authorization are correctly implemented
- No open vulnerabilities in dependencies or code
- Code is clean and adheres to coding standards
Output
- A structured Express application template
- Middleware for common tasks and configurations
- Comprehensive route examples with hierarchy
- Examples of error handling practices
- Static file serving and caching
- Sample authentication and authorization flow
- Example session management and cookie handling
- Request validation and sanitation examples
- Performance benchmark results for key routes
- Documentation for application setup and usage
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 · 58 lines · 17 tokens per session scan A a8752b4b25a6
express-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (995 stars, last pushed 10mo ago), licensed MIT. It adds 17 tokens to every session and 367 once invoked, about $0.0001 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 2026-08-30.
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