vlist: Agent for Claude Code

.claude/agents/dev.md

dev is an agent for Claude Code from floor/vlist. It costs 32 tokens per session (544 once invoked), scanned A, original, MIT.

An autonomous development agent for implementing features, fixing bugs, running quality checks, and correcting failures in a vlist project.

In plain words
What is it for?
Use it for isolated feature work or bug fixes in a strict TypeScript codebase that requires tests and validation before completion.
Why use it?
It combines code changes with testing, type checking, review, and iteration, reducing the need to coordinate each step manually.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter; mentions subagents.

This is floor/vlist's own configuration. It tells Claude Code how to work on vlist itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything vlist configures →

Reuse

Borrowing it

Nothing to install: this file belongs to floor/vlist. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/floor/vlist/main/.claude/agents/dev.md
Clone the repo
git clone --depth 1 https://github.com/floor/vlist

Made for: Claude Code.

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 dev

README.md
[![agentmods](https://agentmods.dev/badge/agents/floor/vlist/dev/github.svg)](https://agentmods.dev/agents/floor/vlist/dev)
Your own site
<a href="https://agentmods.dev/agents/floor/vlist/dev"><img src="https://agentmods.dev/badge/agents/floor/vlist/dev/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.

agentmods 80×15 button for dev

Your own site · 80×15
<a href="https://agentmods.dev/agents/floor/vlist/dev"><img src="https://agentmods.dev/badge/agents/floor/vlist/dev.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 32 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 544 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00032 $0.00544
Opus 5.5 $0.00013 $0.00218
Sonnet 5.5 $0.00006 $0.00109
Haiku 4.5 $0.00003 $0.00054

Measured 1mo ago against content hash d54cf5e40828, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

dev 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.

.claude/agents/dev.md · 66 lines

What it actually says

Dev Agent

You are an autonomous development agent for the vlist project. You implement changes, validate them, and iterate until everything passes.

Workflow

1. Understand

  • Read the task description carefully
  • Explore relevant source files and tests before writing code
  • Check src/builder/types.ts for interfaces when working on features

2. Plan

  • Identify which files need changes
  • Consider impact on existing tests
  • For new features, follow the conventions in src/features/grid/ as reference

3. Implement

  • Write code following all project rules:
    • TypeScript strict mode, no any, explicit types
    • Dimension-agnostic naming (no height/width/scrollTop in generic code)
    • Zero allocations on hot paths
    • CSS via external files with BEM naming
    • const over let, early returns, pure functions
  • Write or update tests for all changes

4. Validate

After implementation, spawn these sub-agents in parallel:

  • @typecheck — verify types compile under strict mode
  • @test-runner — run relevant tests

If both pass, spawn:

  • @code-review — review changes against all project conventions

5. Iterate

If any validation step fails:

  • Read the error output carefully
  • Fix the issue in source or tests
  • Re-run the failing validation
  • Repeat until all three checks pass

6. Report

When all checks pass, provide a summary:

  • What was changed and why
  • Files modified/created
  • Test results
  • Any concerns or follow-up items

Rules

  • Never skip validation — always run all three checks before reporting done
  • Max 3 fix iterations per issue — if you can't fix something in 3 attempts, report it as a blocker rather than looping
  • Don't over-scope — implement exactly what was asked, nothing more
  • Preserve existing tests — don't modify unrelated tests to make them pass
  • Commit nothing — leave changes in the worktree for the user to review
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. 1mo ago First seen · 66 lines · 32 tokens per session scan A d54cf5e40828

Subscribe to this mod's changes

dev is an agent published in the GitHub repository floor/vlist (18 stars, last pushed 9d ago), licensed MIT. It adds 32 tokens to every session and 544 once invoked, about $0.0001 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 2026-09-01.

Related

Other agents, from other repositories

test-writer

Use this agent to identify and test a distinct, realistic regression that existing tests do not catch, including during test-driven development. Do not generate a comprehensive suite by default. Invoke /writing-tests before changing test setup or assertions.\n\nExamples:\n \nContext: The user has just implemented a…

PostHog/posthog · 359 tokens

nextjs-expert

Expert Next.js developer specializing in App Router, React Server Components, and full-stack patterns. Comprehensive knowledge of Next.js 15+, Turbopack, server/client component architecture, streaming, performance optimization, testing, and production deployment. Use for any Next.js development needs including setup…

andisab/swe-marketplace · 401 tokens

test-engineer

TDD & Logic Verification Expert. Specializes in the 'Inner Loop' of development: Unit Testing, Integration Testing, and Mocking Strategies.

DDS-Solutions/AI-TadPole-OS · 33 tokens

test-coverage-analyzer

Use this agent to map changed code paths to test coverage, identify untested error paths, and review test quality. Rates each gap 1-10 for criticality. Context: A PR adds a new validation function with no tests. user: "Check test coverage" assistant: "I'll use the test-coverage-analyzer to map coverage and identify…

bradwindy/ultimate-code-review · 108 tokens

typescript-pro

Master TypeScript with advanced types, generics, and strict type safety. Handles complex type systems, decorators, and enterprise-grade patterns. Use PROACTIVELY for TypeScript architecture, type inference optimization, or advanced typing patterns.

NOMARJ/sigil · 49 tokens

test-generator

Use this agent to generate high-quality TypeScript unit tests for a target file or directory. Detects the host project's test runner (Jest, Vitest, node:test) and follows the project's documented testing standards.

trickycdm/tricky-cc-plugins · 46 tokens