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explore / Backend & APIs / mozg / Deno

Deno · Fundamentals

Answer questions from the Deno fundamentals and getting-started docs: the security and permission model, modules and imports, the runtime Web APIs, workspaces, and running scripts with the exact flags.

371 notes · updated 2026-08-10 · trained 92%

since last sitting: +4 newly passed — this brain is learning · the verified changelog →

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> use mozg/deno-fundamentals — …
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Ask it things like

answers 28/30 on its latest exam
What does Deno's default sandbox security model mean for code execution?Security and Permissions✓
What is the primary module system in Deno?Modules and Imports✓
How do you import a Node.js built-in module in Deno?Modules and Imports✓
What prefix should you use to import npm packages in Deno?Modules and Imports✓
How do you create a basic HTTP server with Deno.serve?Runtime Web APIs✓
How do you grant read access to only a specific directory with Deno?Security and Permissions✓
Where is a Deno workspace defined?Workspaces✓
How do you specify type definitions for an untyped npm package?Modules and Imports✓

What it can answer

30 coverage checks
92%
Answers 28 of the exam's 30 questionsIt answers 28 questions, 4 more than last time.
▲Modules and Imports9 / 10
✓Runtime Web APIs7 / 7
✓Security and Permissions6 / 6
▲Workspaces5 / 6
✓Running Scripts with Flags1 / 1
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Attacks survived

re-run weekly · 2026-08-10
✓gate-battery12/12 known hostile payloads caught by the ingest gate
✓injection-corpusevery active note scanned — no steering language
✓secret-corpusevery active note scanned — no keys or credentials

heuristic scans against known attack classes — measured and dated, not a promise of unpoisonability

Inside

  • import.meta.url returns current module URL · runtime web apis
  • FFI Deno.dlopen to call native libraries · ffi
  • Permission states: granted, prompt, denied · security and permissions
  • Deno.permissions.revoke to downgrade permission · security and permissions
  • import.meta.dirname for local modules only · runtime web apis
  • import.meta.resolve for resolving module specifiers · runtime web apis
  • Permission descriptor syntax in runtime JS · security and permissions
  • Deno.permissions.query to check permission status · security and permissions
  • Permission strength definition · security and permissions
  • Deno.permissions.request to prompt for permission · security and permissions
  • Deno HTTP Server APIs: Deno.serve vs Deno.serveHttp · http_server
  • import.meta.main returns if module is entry point · runtime web apis
  • Deno.serve basic HTTP server example · http_server
  • FFI nonblocking functions return Promise · ffi

Licence

CC BY-NC-SA 4.0

Use it, copy it, build on it, with credit. Selling it is not allowed.