Loading `nitro.config.ts` on Node.js < 2.18 fails with "Unknown file extension .ts"

[meirlamdan]

Environment

• OS: Linux (Cloudflare Pages CI)
• Node version: 22.16.0
• Nitro version: 3.0.260610-beta
• pnpm version: 10.11.1

Reproduction

1. Create a Nitro v3 project with a nitro.config.ts file
2. Deploy to Cloudflare Pages with build command vite build
3. Build fails immediately

Error

Error: Failed to load config file `/opt/buildhome/repo/nitro.config.ts`: Unknown file extension ".ts" for /opt/buildhome/repo/nitro.config.ts.  Hint install `jiti` for compatibility.
    at file:///opt/buildhome/repo/node_modules/.pnpm/nitro@3.0.260610-beta_vite@8.0.16_@types+node@26.0.0_/node_modules/nitro/dist/_libs/c12+rc9.mjs:537:12
...
[cause]: TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for /opt/buildhome/repo/nitro.config.ts

Root Cause

Nitro v3 lists jiti as an optional peer dependency (peerDependenciesMeta), so it is not installed automatically. In CI environments like Cloudflare Pages, jiti is absent and c12 cannot load nitro.config.ts.

Workaround

Explicitly add jiti to devDependencies:

pnpm add -D jiti

Expected Behavior

Either:

• jiti should be a regular (non-optional) dependency of Nitro so it is always available, or
• The documentation / create-nitro-app scaffold should make it clear that jiti must be added manually when using a TypeScript config file

[pi0]

Thanks for report. I just confiremd in here cf pages CI uses older 2.16 version of Node.js that lacks native .ts support.

Simplest workaround for now is to directly install jiti or pass NODE_OPTIONS="--experimental-strip-types environment variable in build command.

[suzunn]

I would add a config-loading matrix before choosing the dependency contract: Node 20 and Node 22.16 with jiti absent, plus a current Node version with native type stripping. The fixture should use a small TypeScript-only construct so it verifies actual config evaluation, not only discovery of nitro.config.ts.

That would lock down both intended paths: either Nitro guarantees TypeScript configs across supported Node versions by shipping jiti, or it fails early with an actionable version/dependency message. It would also prevent a native-loader success on newer CI from masking the Cloudflare Pages failure.