ts

A coding rule requiring exported functions to have explicit return types in TypeScript, a programming language. It applies to functions exposed for use by other code.

In plain words
What is it for?
Reviewing or writing exported TypeScript functions where their return types should be written explicitly.
Why use it?
It makes function outputs clear in the code and avoids relying on inferred types for exported APIs.

Cursor rule for Cursor

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 rules/shunvel/fatcheck/ts
Clone the repo
git clone --depth 1 https://github.com/shunvel/fatcheck

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 27 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 $0.00000 $0.00027
Opus 5 $0.00000 $0.00014
Sonnet 5 $0.00000 $0.00005
Haiku 4.5 $0.00000 $0.00003

Measured yesterday against content hash 2c824cc36d51, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ts 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 yesterday.

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.

fixtures/messy-repo/.cursor/rules/ts.mdc · 8 lines

What it actually says

Prefer explicit return types on exported functions.

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. yesterday First seen · 8 lines · 0 tokens per session scan A 2c824cc36d51

Subscribe to this mod's changes

ts is a cursor rule published in the GitHub repository shunvel/fatcheck (5 stars, last pushed 17d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 27 tokens. 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.