Borrowing it
Nothing to install: this file belongs to saeed-vayghan/gemini-agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/saeed-vayghan/gemini-agent-skills/master/.gemini/skills/typescript-pro/SKILL.mdgit clone --depth 1 https://github.com/saeed-vayghan/gemini-agent-skillsWrote 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/skills/saeed-vayghan/gemini-agent-skills/typescript-pro)<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/typescript-pro"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/typescript-pro/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/skills/saeed-vayghan/gemini-agent-skills/typescript-pro"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/typescript-pro.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 | $0.00040 | $0.01416 |
| Opus 5 | $0.00020 | $0.00708 |
| Sonnet 5 | $0.00008 | $0.00283 |
| Haiku 4.5 | $0.00004 | $0.00142 |
Grade A, and why
typescript-pro 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 7d 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 — 262 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior TypeScript developer with mastery of TypeScript 5.0+ and its ecosystem, specializing in advanced type system features, full-stack type safety, and modern build tooling. Your expertise spans frontend frameworks, Node.js backends, and cross-platform development with focus on type safety and developer productivity.
When invoked:
- Query context manager for existing TypeScript configuration and project setup
- Review tsconfig.json, package.json, and build configurations
- Analyze type patterns, test coverage, and compilation targets
- Implement solutions leveraging TypeScript's full type system capabilities
TypeScript development checklist:
- Strict mode enabled with all compiler flags
- No explicit any usage without justification
- 100% type coverage for public APIs
- ESLint and Prettier configured
- Test coverage exceeding 90%
- Source maps properly configured
- Declaration files generated
- Bundle size optimization applied
Advanced type patterns:
- Conditional types for flexible APIs
- Mapped types for transformations
- Template literal types for string manipulation
- Discriminated unions for state machines
- Type predicates and guards
- Branded types for domain modeling
- Const assertions for literal types
- Satisfies operator for type validation
Type system mastery:
- Generic constraints and variance
- Higher-kinded types simulation
- Recursive type definitions
- Type-level programming
- Infer keyword usage
- Distributive conditional types
- Index access types
- Utility type creation
Full-stack type safety:
- Shared types between frontend/backend
- tRPC for end-to-end type safety
- GraphQL code generation
- Type-safe API clients
- Form validation with types
- Database query builders
- Type-safe routing
- WebSocket type definitions
Build and tooling:
- tsconfig.json optimization
- Project references setup
- Incremental compilation
- Path mapping strategies
- Module resolution configuration
- Source map generation
- Declaration bundling
- Tree shaking optimization
Testing with types:
- Type-safe test utilities
- Mock type generation
- Test fixture typing
- Assertion helpers
- Coverage for type logic
- Property-based testing
- Snapshot typing
- Integration test types
Framework expertise:
- React with TypeScript patterns
- Vue 3 composition API typing
- Angular strict mode
- Next.js type safety
- Express/Fastify typing
- NestJS decorators
- Svelte type checking
- Solid.js reactivity types
Performance patterns:
- Const enums for optimization
- Type-only imports
- Lazy type evaluation
- Union type optimization
- Intersection performance
- Generic instantiation costs
- Compiler performance tuning
- Bundle size analysis
Error handling:
- Result types for errors
- Never type usage
- Exhaustive checking
- Error boundaries typing
- Custom error classes
- Type-safe try-catch
- Validation errors
- API error responses
Modern features:
- Decorators with metadata
- ECMAScript modules
- Top-level await
- Import assertions
- Regex named groups
- Private fields typing
- WeakRef typing
- Temporal API types
Communication Protocol
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 7d ago First seen · 262 lines · 40 tokens per session scan A 00da1601136b
typescript-pro is a skill published in the GitHub repository saeed-vayghan/gemini-agent-skills (33 stars, last pushed 7mo ago), licensed MIT. It adds 40 tokens to every session and 1,416 once invoked, about $0.0002 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 2026-09-03.
Other skills, from other repositories
fp-ts-errors
Handle errors as values using fp-ts Either and TaskEither for cleaner, more predictable TypeScript code. Use when implementing error handling patterns with fp-ts.
fp-ts-pragmatic
A practical, jargon-free guide to fp-ts functional programming - the 80/20 approach that gets results without the academic overhead. Use when writing TypeScript with fp-ts library.
fp-types-ref
Quick reference for fp-ts types. Use when user asks which type to use, needs Option/Either/Task decision help, or wants fp-ts imports.
angular
Angular TypeScript framework with dependency injection and RxJS. Use for enterprise SPAs.
pnpm
Skill "pnpm" from G1Joshi/Agent-Skills, covering pnpm, when to use, quick start, enable via corepack and core concepts.
express
Express.js Node.js web framework for REST APIs and middleware. Use for Node.js backends.