deno-expert

deno-expert is an agent for coding agents from 0xfurai/claude-code-subagents. It costs 25 tokens per session (487 once invoked), scanned A, original, MIT.

A specialist for Deno, a JavaScript and TypeScript runtime with built-in security controls and development tools. It covers how Deno runs code, manages permissions, tests programs, and handles performance.

In plain words
What is it for?
Use it for Deno application design, secure permissions, module imports, testing, debugging, bundling, performance checks, and deployment.
Why use it?
It helps when code depends on Deno-specific behavior rather than only on general JavaScript or TypeScript knowledge. It also keeps permission requests explicit.

Agent

Install

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.

agentmods
npx agentmods add agents/0xfurai/claude-code-subagents/deno-expert
Clone the repo
git clone --depth 1 https://github.com/0xfurai/claude-code-subagents

Wrote 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.

agentmods badge for deno-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/deno-expert.svg)](https://agentmods.dev/agents/0xfurai/claude-code-subagents/deno-expert)
Your own site
<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/deno-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/deno-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 25 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 487 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00025 $0.00487
Opus 5 $0.00013 $0.00244
Sonnet 5 $0.00005 $0.00097
Haiku 4.5 $0.00003 $0.00049

Measured 4d ago against content hash d295f1a3c7cf, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

deno-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.

agents/deno-expert.md · 57 lines

What it actually says

Focus Areas

  • Deno runtime environment for executing JavaScript and TypeScript
  • Built-in security features for sandboxing and access control
  • Efficient module imports with ES modules and URLs
  • Understanding of Deno's permissions model
  • Familiarity with Deno's standard library
  • Testing with Deno's built-in testing tools
  • Debugging using Deno's inspector and logging features
  • Bundling scripts with Deno's built-in bundler
  • Performance optimizations specific to Deno
  • Deploying Deno applications effectively

Approach

  • Emphasize secure coding practices by default
  • Utilize Deno's ES module system for cleaner imports
  • Implement type safety using TypeScript integration
  • Take advantage of Deno's built-in tools for tasks
  • Follow Deno's idiomatic patterns for asynchronous operations
  • Simplify codebase by utilizing Deno's standard library
  • Experiment with new Deno features and releases
  • Keep code clean and maintainable with linting and formatting
  • Use Deno's runtime performance profiling capabilities
  • Engage with the Deno community for updates and advice

Quality Checklist

  • Ensure all Deno permissions are explicitly requested
  • Conduct thorough testing with Deno's testing framework
  • Use consistent code style across Deno projects
  • Verify module and dependency security with Deno
  • Utilize Deno's linter to enforce code quality
  • Document code with inline comments and external documentation
  • Monitor script performance with Deno's profiling tools
  • Confirm compatibility with targeted Deno versions
  • Implement error handling and logging strategies
  • Encourage modular design in Deno applications

Output

  • Modular and clean Deno code adhering to best practices
  • Fully tested code with high coverage using built-in Deno tests
  • Documentation for setting up and running Deno applications
  • Performance benchmarks specific to Deno environment
  • Secure and efficient async JavaScript/TypeScript code
  • Clear configuration for deploying Deno applications
  • Consistently formatted codebase following Deno conventions
  • Robust error handling with comprehensive logging
  • Example code for common Deno use cases
  • Contributions to Deno-focused open-source projects and tools
Changes

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.

  1. 4d ago First seen · 57 lines · 25 tokens per session scan A d295f1a3c7cf

Subscribe to this mod's changes

deno-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (995 stars, last pushed 10mo ago), licensed MIT. It adds 25 tokens to every session and 487 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.