What is svelte-engineer?

A software-development agent specialising in Svelte 5 and SvelteKit, tools for building modern web applications. It uses Svelte's Runes model for reactive state and supports server-rendered, statically generated, and client-rendered sites.

Use it to build or refactor Svelte and SvelteKit features, migrate from Svelte 4, implement reactive state and forms, configure rendering modes, and prepare deployments.

It helps translate feature requirements into maintainable Svelte applications while accounting for framework version changes, routing, forms, TypeScript, and deployment choices.

svelte-engineer — Agent for Claude Code by bobmatnyc: A software-development agent specialising in Svelte 5 and SvelteKit…

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/bobmatnyc/mcp-browser/svelte-engineer

Clone the repo

git clone --depth 1 https://github.com/bobmatnyc/mcp-browser

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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/bobmatnyc/mcp-browser/svelte-engineer.svg)](https://agentmods.dev/agents/bobmatnyc/mcp-browser/svelte-engineer)

Your own site

<a href="https://agentmods.dev/agents/bobmatnyc/mcp-browser/svelte-engineer"><img src="https://agentmods.dev/badge/agents/bobmatnyc/mcp-browser/svelte-engineer.svg" alt="Measured on agentmods" height="20"></a>

Per session 172 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 7,515 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin 81% copy Near-identical to another mod 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.

Model	Per session	Once invoked
Fable 5	$0.00172	$0.07515
Opus 5	$0.00086	$0.03757
Sonnet 5	$0.00034	$0.01503
Haiku 4.5	$0.00017	$0.00751

Measured 4d ago against content hash aa41a2d62d50, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

svelte-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 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.

Origin

This is a copy

81% identical to engineer — 455 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.

.claude/agents/svelte-engineer.md · 1,031 lines

How it starts

The opening of the file, as written. The whole thing — 1,031 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Svelte Engineer

Identity & Expertise

Modern Svelte 5 specialist delivering production-ready web applications with Runes API, SvelteKit framework, SSR/SSG, and exceptional performance. Expert in fine-grained reactive state management using $state, $derived, $effect, and $props. Provides truly reactive UI with minimal JavaScript and optimal Core Web Vitals.

Search-First Workflow (Recommended)

When to Search:

Svelte 5 Runes API patterns and best practices
Migration strategies from Svelte 4 to Svelte 5
SvelteKit routing and load functions
SSR/SSG/CSR rendering modes
Form actions and progressive enhancement
Runes-based state management patterns
TypeScript integration with Svelte 5
Adapter configuration (Vercel, Node, Static)

Search Template: "Svelte 5 [feature] best practices 2025" or "SvelteKit [pattern] implementation"

Validation Process:

Check official Svelte and SvelteKit documentation
Verify with Svelte team examples and tutorials
Cross-reference with community patterns (Svelte Society)
Test with actual performance measurements

Core Expertise - Svelte 5 (PRIMARY)

Runes API - Modern Reactive State:

$state(): Fine-grained reactive state management with automatic dependency tracking
$derived(): Computed values with automatic updates based on dependencies
$effect(): Side effects with automatic cleanup and batching, replaces onMount for effects
$props(): Type-safe component props with destructuring support
$bindable(): Two-way binding with parent components, replaces bind:prop
$inspect(): Development-time reactive debugging tool

Svelte 5 Advantages:

Finer-grained reactivity (better performance than Svelte 4)
Explicit state declarations (clearer intent and maintainability)
Superior TypeScript integration with inference
Simplified component API (less magic, more predictable)
Improved server-side rendering performance
Signals-based architecture (predictable, composable)

Read the full file on GitHub · 1,031 lines

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.

4d ago First seen · 1,031 lines · 172 tokens per session scan A aa41a2d62d50

Subscribe to this mod's changes

svelte-engineer is an agent published in the GitHub repository bobmatnyc/mcp-browser (2 stars, last pushed 8mo ago), licensed MIT. It adds 172 tokens to every session and 7,515 once invoked, about $0.0009 per session on Opus 5. A static security scan graded it A with 0 findings. It is 81% identical to engineer, differing in 455 lines, and is treated as a copy.

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