# Typescript Eval

> Test TypeScript code snippets before persisting as skills

- Skill: `vellum-ai/typescript-eval` (Agent Skill)
- Install (CLI): `npx skillmds@latest add vellum-ai/typescript-eval`
- Raw SKILL.md: https://api.skillmd.com/api/skills/vellum-ai/typescript-eval/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: vellum-ai (https://skillmd.com/u/vellum-ai)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/vellum-ai/typescript-eval

---


# TypeScript Evaluation

When you need to test a TypeScript snippet before persisting it as a managed skill, use `bash` directly.

## Workflow

### 1. Write the snippet to a temp file

```
bash command="mkdir -p /tmp/vellum-eval && cat > /tmp/vellum-eval/snippet.ts << 'SNIPPET_EOF'
<your code here>
SNIPPET_EOF"
```

### 2. Run it with bun

```
bash command="bun run /tmp/vellum-eval/snippet.ts" timeout_seconds=10
```

### 3. For function-based testing

If the snippet exports a `default` or `run` function, write a runner script:

```
bash command="cat > /tmp/vellum-eval/runner.ts << 'RUNNER_EOF'
import * as mod from './snippet.ts';
const fn = (mod as any).default ?? (mod as any).run;
const input = {}; // mock input
const result = await fn(input);
console.log(JSON.stringify(result, null, 2));
RUNNER_EOF"
```

Then run the runner:

```
bash command="bun run /tmp/vellum-eval/runner.ts" timeout_seconds=10
```

### 4. Clean up

```
bash command="rm -rf /tmp/vellum-eval/"
```

## Guidelines

- **Iteration limit:** Max 3 attempts before asking the user for guidance.
- **After successful test:** Persist with `scaffold_managed_skill` only after explicit user consent.
- **Timeout:** Use `timeout_seconds=10` (or up to 20 for complex snippets).
- **Never persist or delete skills without explicit user confirmation.**