Native TypeScript type stripping

Node's built-in TypeScript execution pipeline and its runtime limits.

Timeline

Change	PR or issue	Verified releases
--experimental-transform-types	nodejs/node#54283	v22.7.0, v23.0.0
module.stripTypeScriptTypes()	#55282, nodejs/node#54300	v22.13.0, v23.2.0
TypeScript in --eval and STDIN	#56359	v22.14.0, v23.6.0, v24.0.0
Default strip-only execution	#56350, nodejs/typescript#17	v22.18.0, v23.6.0, v24.0.0
Stable status	#60600	v24.12.0, v25.2.0
Remove transform mode	#61803	v26.0.0

Runtime pipeline

• Node delegates stripping to Amaro. amaro.transformSync is loaded in v24.0.0 typescript.js#L47-L48, and processTypeScriptCode owns the internal flow (typescript.js#L144).
• ESM format detection maps .ts to TypeScript formats according to package type and syntax detection (v24.0.0 get_format.js#L133-L149).
• The CJS loader strips TypeScript formats before compilation (v24.0.0 loader.js#L1125-L1127).
• Stripping runs after the module-hook chain and before translation (v24.15.0 loader.js#L408-L414).

Public API and loader path

node:module exposes stripTypeScriptTypes(), but it differs from the loader path.

Aspect	Public API	Internal loader
node_modules	No restriction	Throws ERR_UNSUPPORTED_NODE_MODULES_TYPE_STRIPPING (v24.15.0 typescript.js#L180-L183)
Compile cache	Not used	Keyed by filename (v24.15.0 typescript.js#L198)
Mode	Strip or transform through v25	Strip only in v26 (v26.4.0 typescript.js#L101)

Runtime limits

• Node ignores tsconfig.json; paths and downleveling are unsupported (v26.0.0 typescript.md#L80-L88).
• Relative TypeScript imports require explicit extensions (v26.0.0 typescript.md#L128-L136).
• .tsx, non-erasable syntax, TypeScript in node_modules, TypeScript data URLs, and extensionless TypeScript executables remain unsupported (v26.0.0 typescript.md#L128-L217).