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 agentmods add skills/aaronbassett/agent-foundry/typescript-corenpx skills add aaronbassett/agent-foundry --skill typescript-coregit clone --depth 1 https://github.com/aaronbassett/agent-foundryWrote 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/aaronbassett/agent-foundry/typescript-core)<a href="https://agentmods.dev/skills/aaronbassett/agent-foundry/typescript-core"><img src="https://agentmods.dev/badge/skills/aaronbassett/agent-foundry/typescript-core.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 | $0.00087 | $0.01012 |
| Opus 5 | $0.00044 | $0.00506 |
| Sonnet 5 | $0.00017 | $0.00202 |
| Haiku 4.5 | $0.00009 | $0.00101 |
Grade A, and why
devs:typescript-core 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 5d 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 — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TypeScript Core Development
Reference hub for TypeScript work. Verify versions, compiler options, and APIs against npm (npm view <pkg> version) and the installed toolchain — never from trained knowledge.
Reference routing
Load references on demand — not all at once.
| Reference | Use when |
|---|---|
| strict-configuration.md | tsconfig strictness anatomy, compiler defaults, ESLint flat config |
| common-errors.md | The genuinely confusing compiler errors (TS2742, TS1484, TS1479, ...) |
| error-handling.md | Result types (True Myth), Effect error channel, boundary strategy |
| patterns.md | ts-pattern, builder/newtype idioms, satisfies / const type params / NoInfer / using |
| testing.md | vitest config, mocking, testing-library setup, MSW, coverage |
| principles.md | Type-safety posture: unknown at boundaries, parse-don't-validate, exhaustiveness |
| project-structure.md | exports/imports maps, #-subpath imports, project references, run-TS-directly |
| dependencies.md | Version policy, updates, knip/publint/arethetypeswrong, audit, provenance |
| packages-always-use.md | The curated default stack (zod, Effect, True Myth, LogTape, ...) |
| packages-utilities.md | type-fest (Tagged), es-toolkit, ts-pattern, TypeID |
| packages-cli.md | CLI framework decision table, @inquirer/prompts, Ink 7, ora, listr2 |
For code-review checklists use the devs:code-review skill; React UI work belongs to devs:react-core / the react-dev agent.
Decision guides
Package manager: detect from the lockfile in existing projects and conform (pnpm-lock.yaml/bun.lock/yarn.lock/package-lock.json); prefer pnpm otherwise. Wrap network-touching commands in Socket Firewall when available: sfw pnpm add …, sfw npm install.
What ships with it
16 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.
- assets/tsconfig-templates/library.json 749 B
- assets/tsconfig-templates/monorepo-base.json 528 B
- assets/tsconfig-templates/strict-base.json 843 B
- assets/tsconfig-templates/strict-node.json 816 B
- assets/tsconfig-templates/strict-react.json 539 B
- references/common-errors.md 5.5 KB
- references/dependencies.md 3.8 KB
- references/error-handling.md 3.8 KB
- references/packages-always-use.md 5.4 KB
- references/packages-cli.md 3.7 KB
- references/packages-utilities.md 3.6 KB
- references/patterns.md 3.4 KB
- references/principles.md 1.6 KB
- references/project-structure.md 3.7 KB
- references/strict-configuration.md 4.3 KB
- references/testing.md 5.1 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.
- 5d ago First seen · 54 lines · 87 tokens per session scan A f2fc626c40b4
devs:typescript-core is a skill published in the GitHub repository aaronbassett/agent-foundry (4 stars, last pushed 20d ago), licensed MIT. It adds 87 tokens to every session and 1,012 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 2026-08-31.
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