PermissionDenied: Requires read access

Deno is secure by default — you need to explicitly grant permissions.

Fix 1: Add permission flags

# ❌ No permissions
deno run app.ts

# ✅ Grant specific permissions
deno run --allow-read --allow-net app.ts

# ✅ Grant all (development only)
deno run -A app.ts

Fix 2: Common permission flags

--allow-read     # File system read
--allow-write    # File system write
--allow-net      # Network access
--allow-env      # [Environment variables](/blog/what-is-environment-variables/)
--allow-run      # Run subprocesses

Fix 3: Limit scope

# Only allow reading from specific directory
deno run --allow-read=./data app.ts

# Only allow network to specific hosts
deno run --allow-net=api.example.com app.ts