An agent for checking type safety and TypeScript usage when changing features, data types, or type-related errors.

Use it to check tool parameter schemas, explicit interfaces and types, safe handling of optional values, exports, and appropriate use of unknown instead of any.

It helps prevent invalid values, missing definitions, and weak typing from spreading through the codebase.

How jamesjfoong/github-pr-review-mcp configures Claude Code and Cursor

Reuse

Borrowing it

Nothing to install: this file belongs to jamesjfoong/github-pr-review-mcp. 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/jamesjfoong/github-pr-review-mcp/main/.cursor/agents/type-safety.md

Clone the repo

git clone --depth 1 https://github.com/jamesjfoong/github-pr-review-mcp

Made for: Claude Code, Cursor.

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/jamesjfoong/github-pr-review-mcp/type-safety/github.svg)](https://agentmods.dev/agents/jamesjfoong/github-pr-review-mcp/type-safety)

Your own site

<a href="https://agentmods.dev/agents/jamesjfoong/github-pr-review-mcp/type-safety"><img src="https://agentmods.dev/badge/agents/jamesjfoong/github-pr-review-mcp/type-safety/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.

Your own site · 80×15

<a href="https://agentmods.dev/agents/jamesjfoong/github-pr-review-mcp/type-safety"><img src="https://agentmods.dev/badge/agents/jamesjfoong/github-pr-review-mcp/type-safety.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 346 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.

Model	Per session	Once invoked
Fable 5.1	$0.00027	$0.00346
Opus 5.5	$0.00011	$0.00138
Sonnet 5.5	$0.00005	$0.00069
Haiku 4.5	$0.00003	$0.00035

Measured 2mo ago against content hash 5d206fec897b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

type-safety 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 2mo 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.

.cursor/agents/type-safety.md · 56 lines

What it actually says

Type Safety Agent

Purpose: Ensures type safety and proper TypeScript usage throughout the codebase.

Responsibilities

Verify all tool parameters have Zod schemas
Prefer explicit interface or type definitions over z.infer<typeof Schema>
Check for proper type definitions (no any unless necessary)
Use ? for optional properties (don't use | null | undefined)
Use optional chaining (?.) when accessing values
Verify all exports have proper types

When to Use

When adding new features, modifying types, or fixing type errors.

Key Rules

All parameters must have Zod schemas in src/types.ts
Use explicit type definitions alongside Zod schemas
Avoid any - use unknown if type is truly unknown
Prefer ? over | undefined for optional fields
Use | null when external APIs can return null
Strong typing: Always use explicit, strong types

Examples

// CORRECT - Explicit type definition with Zod schema
export const PRParamsSchema = z.object({
  owner: z.string(),
  repo: z.string(),
  prNumber: z.number(),
});

export interface PRParams {
  owner: string;
  repo: string;
  prNumber: number;
}

// CORRECT - Use optional property
interface GoodType {
  value?: string;
}

// CORRECT - Use optional chaining when accessing
const result = obj?.value ?? "default";

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.

2mo ago First seen · 56 lines · 27 tokens per session scan A 5d206fec897b

Subscribe to this mod's changes

type-safety is an agent published in the GitHub repository jamesjfoong/github-pr-review-mcp (1 stars, last pushed 9mo ago), licensed MIT. It adds 27 tokens to every session and 346 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 2026-08-31.

Languages TypeScript github mcp pull-request review

type-safety next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
type-safetyjamesjfoong/github-pr-review-mcp	Agent	1	9mo ago	MIT	A	27	Claude Code, Cursor
Typescript ProTheSethRose/Copilot-Skills	Agent	3	11mo ago	MIT	A	41	Claude Code
frontend-devvibeeval/vibecosystem	Agent	539	2d ago	MIT	A	22	Claude Code
frontend-engineerjpoley/flowspec	Agent	50	28d ago	Apache-2.0	A	24	Claude Code
effect-architecture-reviewerbengous/claude-code-plugins	Agent	6	yesterday	MIT	A	50	Claude Code
typescript-code-revieweroikon48/claudecode-book	Agent	24	2mo ago	MIT	A	157	Claude Code
fastmcp-ts-expertjpoutrin/product-forge	Agent	16	8mo ago	MIT	A	26	Claude Code

github-pr-review-mcp: Agent for Claude Code