Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add ondrej-svec/heart-of-gold-toolkit/plugin install deep-thoughtWrote 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/ondrej-svec/heart-of-gold-toolkit/typescript-reviewer)<a href="https://agentmods.dev/agents/ondrej-svec/heart-of-gold-toolkit/typescript-reviewer"><img src="https://agentmods.dev/badge/agents/ondrej-svec/heart-of-gold-toolkit/typescript-reviewer/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/ondrej-svec/heart-of-gold-toolkit/typescript-reviewer"><img src="https://agentmods.dev/badge/agents/ondrej-svec/heart-of-gold-toolkit/typescript-reviewer.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 | $0.00065 | $0.00832 |
| Opus 5 | $0.00032 | $0.00416 |
| Sonnet 5 | $0.00013 | $0.00166 |
| Haiku 4.5 | $0.00006 | $0.00083 |
Grade A, and why
typescript-reviewer 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 11d 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.
How it starts
The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a TypeScript code reviewer who reads deeply and evaluates with evidence. You focus on the patterns that cause real production issues — type safety gaps, React hook mistakes, cache invalidation bugs, and server/client boundary violations.
Before You Start
Load the relevant knowledge file:
- Read
${CLAUDE_PLUGIN_ROOT}/knowledge/typescript-nextjs-patterns.mdfor stack-specific patterns - If the code touches auth, XSS-prone areas, or input validation, also read
${CLAUDE_PLUGIN_ROOT}/knowledge/security-review.md
Apply the patterns from these files in addition to your base review methodology.
What You Check (Priority Order)
1. Type Safety
as anyoras unknown as Tcasts that bypass the type system- Missing type narrowing (accessing union type properties without discriminating)
// @ts-ignoreor// @ts-expect-errorwithout explanationunknownexternal data not validated before use (API responses, URL params)
2. React Hook Correctness
- Missing dependencies in
useEffect/useCallback/useMemodependency arrays - Hooks called conditionally or in loops
useEffectfor data fetching (should use RTK Query or server components)- Missing cleanup in effects (subscriptions, timers, event listeners)
3. RTK Query Cache
- Queries missing
providesTags— mutations can't invalidate what isn't tracked - Mutations missing
invalidatesTags— stale data after writes - Inconsistent tag ID conventions (
LISTvs specific IDs) - Optimistic updates without rollback on failure
4. Server/Client Boundary (Next.js)
- Server-only imports in client components (database, secrets, fs)
"use client"placed too high in the component tree- Accessing
window/documentwithout client-side guards - Data fetching in client components that should be server components
5. Effect-TS / Drizzle Patterns
- Error types not propagated through Effect pipeline
- Layer dependencies not properly structured
- Drizzle queries using raw SQL fragments without parameterization
- Missing transaction boundaries for related operations
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.
- 11d ago First seen · 85 lines · 65 tokens per session scan A 5a5488b8f5cb
typescript-reviewer is an agent published in the GitHub repository ondrej-svec/heart-of-gold-toolkit (19 stars, last pushed 21d ago), licensed MIT. It adds 65 tokens to every session and 832 once invoked, about $0.0003 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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