deno

Deno

Purpose

Build TypeScript services on Deno 2 with least-privilege permissions, JSR-first dependencies, built-in tooling (fmt, lint, test, check, compile) and a choice of bare Deno.serve, Hono, Oak or Fresh.

Agent Protocol

Trigger

Exact user phrases: "deno", "deno 2", "deno.json", "deno task", "deno compile", "deno test", "Deno.serve", "Deno KV", "JSR", "deno permissions", "Fresh framework".

Input Context

• Deno version (assume 2.x) and deployment target (Deno Deploy, Docker, compiled binary).
• Framework (bare Deno.serve, Hono, Oak, Fresh).
• Data store (Deno KV, PostgreSQL via npm:pg/jsr:@db/postgres, Redis).
• Required permissions (net, read, write, env, run, ffi).

Output Artifact

deno.json, server code, tests and run/deploy commands with explicit permissions. No files unless requested.

Response Format

Deno: 2.x   Framework: {bare|Hono|Oak|Fresh}
Permissions: --allow-net={hosts} --allow-env={vars} --allow-read={paths}
Deps: {jsr:/npm: specifiers in deno.json imports}
Files: {deno.json, src/main.ts, tests}
Run: deno task {dev|start|test}

Decisions

Framework

Need	Choice
Small API, no deps	Deno.serve + URLPattern
Typed REST API with middleware ecosystem, multi-runtime	Hono (jsr:@hono/hono)
Koa-style middleware, existing Oak codebase	Oak (jsr:@oak/oak)
Server-rendered pages with interactive islands	Fresh 2 (jsr:@fresh/core, built on Vite)

Dependencies

• Prefer JSR (jsr:@std/..., jsr:@hono/hono): semver, TypeScript source, provenance.
• Use npm (npm:pkg@^x) for packages that only exist there; Deno 2 supports package.json and node_modules when needed.
• Avoid https://deno.land/std and deno.land/x URLs in new code: the standard library now lives on JSR as @std/*.
• Declare everything in deno.json imports; deno.lock is created and checked automatically.

Permissions

Grant the narrowest scope: --allow-net=api.example.com:443,0.0.0.0:8000, --allow-env=DATABASE_URL,PORT, --allow-read=./static. Avoid -A outside local scripts. Deno 2 also offers --deny-* flags to carve exceptions out of broader grants.