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.
npx skills add pledgeandgrow/pledge-skills --skill typescriptgit clone --depth 1 https://github.com/pledgeandgrow/pledge-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/pledgeandgrow/pledge-skills/typescript)<a href="https://agentmods.dev/skills/pledgeandgrow/pledge-skills/typescript"><img src="https://agentmods.dev/badge/skills/pledgeandgrow/pledge-skills/typescript.svg" alt="Measured on agentmods" 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 | $0.00079 | $0.00948 |
| Opus 5 | $0.00039 | $0.00474 |
| Sonnet 5 | $0.00016 | $0.00190 |
| Haiku 4.5 | $0.00008 | $0.00095 |
Grade A, and why
typescript-docs 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.
How it starts
The opening of the file, as written. The whole thing — 128 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TypeScript Expert (v5.x)
Official Documentation: https://www.typescriptlang.org/docs/
Quick Reference
| Topic | File |
|---|---|
| Primitives, arrays, objects, unions, enums | everyday-types.md |
| Property modifiers, index signatures, tuples, extending types | object-types.md |
Function types, overloads, generics, rest params, this |
functions.md |
| Generic basics, constraints, classes, variance | generics.md |
| Type guards, narrowing, discriminated unions, exhaustiveness | narrowing.md |
| Classes: fields, constructors, visibility, static, abstract | classes.md |
| ES modules, CommonJS, resolution, namespaces | modules.md |
Mapped types, conditional types, template literals, keyof |
advanced-types.md |
| All built-in utility types | utility-types.md |
tsconfig.json: compiler options, strict flags, output |
tsconfig.md |
| Decorators (legacy & TC39 stage 3) | decorators.md |
| JSX, React types, intrinsic elements | jsx.md |
.d.ts files, ambient declarations, module augmentation |
declaration-files.md |
| Structural typing, assignability, variance | type-compatibility.md |
| Migrating from JS, gradual adoption strategies | migrating.md |
Core Philosophy
TypeScript adds a static type system to JavaScript. Key principles:
- Structural typing — types are compared by shape, not by name
- Type erasure — types are removed at compile time; no runtime overhead
- Gradual adoption — can be added to existing JS projects incrementally
- Inference — types are inferred when not explicitly annotated
- Soundness trade-offs — practical type safety over perfect soundness
The Type Hierarchy
unknown ← everything is assignable to unknown (top type)
├── object
│ ├── Array, Function, Date, RegExp, etc.
│ └── {} (empty object type)
│ ├── { a: string } ← specific object types
│ └── Record<string, T>
├── string
├── number
├── boolean
├── bigint
├── symbol
└── null / undefined
never ← assignable to everything (bottom type, empty union)
What ships with it
15 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.
- advanced-types.md 4.5 KB
- classes.md 3.9 KB
- declaration-files.md 3.5 KB
- decorators.md 4.0 KB
- everyday-types.md 4.4 KB
- functions.md 3.9 KB
- generics.md 3.3 KB
- jsx.md 5.2 KB
- migrating.md 4.2 KB
- modules.md 2.6 KB
- narrowing.md 3.7 KB
- object-types.md 3.0 KB
- tsconfig.md 5.5 KB
- type-compatibility.md 3.5 KB
- utility-types.md 3.9 KB
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 · 128 lines · 79 tokens per session scan A f8608bcc8bd6
typescript-docs is a skill published in the GitHub repository pledgeandgrow/pledge-skills (10 stars, last pushed 1mo ago), licensed MIT. It adds 79 tokens to every session and 948 once invoked, about $0.0004 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.
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