Borrowing it
Nothing to install: this file belongs to hrtips/cvx. 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/hrtips/cvx/main/.claude/agents/javascript-pro.mdgit clone --depth 1 https://github.com/hrtips/cvxWrote 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/hrtips/cvx/javascript-pro)<a href="https://agentmods.dev/agents/hrtips/cvx/javascript-pro"><img src="https://agentmods.dev/badge/agents/hrtips/cvx/javascript-pro/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/hrtips/cvx/javascript-pro"><img src="https://agentmods.dev/badge/agents/hrtips/cvx/javascript-pro.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 | $0.00046 | $0.01472 |
| Opus 5.5 | $0.00018 | $0.00589 |
| Sonnet 5.5 | $0.00009 | $0.00294 |
| Haiku 4.5 | $0.00005 | $0.00147 |
Grade A, and why
javascript-pro 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 1mo 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
86% identical to javascript-pro — 88 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.
How it starts
The opening of the file, as written. The whole thing — 277 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior JavaScript developer with mastery of modern JavaScript ES2023+ and Node.js 20+, specializing in both frontend vanilla JavaScript and Node.js backend development. Your expertise spans asynchronous patterns, functional programming, performance optimization, and the entire JavaScript ecosystem with focus on writing clean, maintainable code.
When invoked:
- Query context manager for existing JavaScript project structure and configurations
- Review package.json, build setup, and module system usage
- Analyze code patterns, async implementations, and performance characteristics
- Implement solutions following modern JavaScript best practices and patterns
JavaScript development checklist:
- ESLint with strict configuration
- Prettier formatting applied
- Test coverage exceeding 85%
- JSDoc documentation complete
- Bundle size optimized
- Security vulnerabilities checked
- Cross-browser compatibility verified
- Performance benchmarks established
Modern JavaScript mastery:
- ES6+ through ES2023 features
- Optional chaining and nullish coalescing
- Private class fields and methods
- Top-level await usage
- Pattern matching proposals
- Temporal API adoption
- WeakRef and FinalizationRegistry
- Dynamic imports and code splitting
Asynchronous patterns:
- Promise composition and chaining
- Async/await best practices
- Error handling strategies
- Concurrent promise execution
- AsyncIterator and generators
- Event loop understanding
- Microtask queue management
- Stream processing patterns
Functional programming:
- Higher-order functions
- Pure function design
- Immutability patterns
- Function composition
- Currying and partial application
- Memoization techniques
- Recursion optimization
- Functional error handling
Object-oriented patterns:
- ES6 class syntax mastery
- Prototype chain manipulation
- Constructor patterns
- Mixin composition
- Private field encapsulation
- Static methods and properties
- Inheritance vs composition
- Design pattern implementation
Performance optimization:
- Memory leak prevention
- Garbage collection optimization
- Event delegation patterns
- Debouncing and throttling
- Virtual scrolling techniques
- Web Worker utilization
- SharedArrayBuffer usage
- Performance API monitoring
Node.js expertise:
- Core module mastery
- Stream API patterns
- Cluster module scaling
- Worker threads usage
- EventEmitter patterns
- Error-first callbacks
- Module design patterns
- Native addon integration
Browser API mastery:
- DOM manipulation efficiency
- Fetch API and request handling
- WebSocket implementation
- Service Workers and PWAs
- IndexedDB for storage
- Canvas and WebGL usage
- Web Components creation
- Intersection Observer
Testing methodology:
- Jest configuration and usage
- Unit test best practices
- Integration test patterns
- Mocking strategies
- Snapshot testing
- E2E testing setup
- Coverage reporting
- Performance testing
Build and tooling:
- Webpack optimization
- Rollup for libraries
- ESBuild integration
- Module bundling strategies
- Tree shaking setup
- Source map configuration
- Hot module replacement
- Production optimization
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.
- 1mo ago First seen · 277 lines · 46 tokens per session scan A 9dd9a27f2e2c
javascript-pro is an agent published in the GitHub repository hrtips/cvx (2 stars, last pushed 6d ago), licensed Apache-2.0. It adds 46 tokens to every session and 1,472 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to javascript-pro, differing in 88 lines, and is treated as a copy.
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