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Configuration

ts-node supports a variety of options which can be specified via tsconfig.json, as CLI flags, as environment variables, or programmatically.

For a complete list, see Options.

CLI flags​

ts-node CLI flags must come before the entrypoint script. For example:

shell
$ ts-node --project tsconfig-dev.json say-hello.ts Ronald
Hello, Ronald!
shell
$ ts-node --project tsconfig-dev.json say-hello.ts Ronald
Hello, Ronald!

ts-node automatically finds and loads tsconfig.json. Most ts-node options can be specified in a "ts-node" object using their programmatic, camelCase names. We recommend this because it works even when you cannot pass CLI flags, such as node --require ts-node/register and when using shebangs.

Use --skipProject to skip loading the tsconfig.json. Use --project to explicitly specify the path to a tsconfig.json.

When searching, it is resolved using the same search behavior as tsc. By default, this search is performed relative to the entrypoint script. In --cwdMode or if no entrypoint is specified -- for example when using the REPL -- the search is performed relative to --cwd / process.cwd().

You can use this sample configuration as a starting point:

tsconfig.json
json
{
  // This is an alias to @tsconfig/node16: https://github.com/tsconfig/bases
  "extends": "ts-node/node16/tsconfig.json",
  // Most ts-node options can be specified here using their programmatic names.
  "ts-node": {
    // It is faster to skip typechecking.
    // Remove if you want ts-node to do typechecking.
    "transpileOnly": true,
    "files": true,
    "compilerOptions": {
      // compilerOptions specified here will override those declared below,
      // but *only* in ts-node.  Useful if you want ts-node and tsc to use
      // different options with a single tsconfig.json.
    }
  },
  "compilerOptions": {
    // typescript options here
  }
}
tsconfig.json
json
{
  // This is an alias to @tsconfig/node16: https://github.com/tsconfig/bases
  "extends": "ts-node/node16/tsconfig.json",
  // Most ts-node options can be specified here using their programmatic names.
  "ts-node": {
    // It is faster to skip typechecking.
    // Remove if you want ts-node to do typechecking.
    "transpileOnly": true,
    "files": true,
    "compilerOptions": {
      // compilerOptions specified here will override those declared below,
      // but *only* in ts-node.  Useful if you want ts-node and tsc to use
      // different options with a single tsconfig.json.
    }
  },
  "compilerOptions": {
    // typescript options here
  }
}

Our bundled JSON schema lists all compatible options.

@tsconfig/bases​

@tsconfig/bases maintains recommended configurations for several node versions. As a convenience, these are bundled with ts-node.

tsconfig.json
json
{
  "extends": "ts-node/node16/tsconfig.json",
  // Or install directly with `npm i -D @tsconfig/node16`
  "extends": "@tsconfig/node16/tsconfig.json",
}
tsconfig.json
json
{
  "extends": "ts-node/node16/tsconfig.json",
  // Or install directly with `npm i -D @tsconfig/node16`
  "extends": "@tsconfig/node16/tsconfig.json",
}

Default config​

If no tsconfig.json is loaded from disk, ts-node will use the newest recommended defaults from @tsconfig/bases compatible with your node and typescript versions. With the latest node and typescript, this is @tsconfig/node16.

Older versions of typescript are incompatible with @tsconfig/node16. In those cases we will use an older default configuration.

When in doubt, ts-node --showConfig will log the configuration being used, and ts-node -vv will log node and typescript versions.

node flags​

node flags must be passed directly to node; they cannot be passed to the ts-node binary nor can they be specified in tsconfig.json

We recommend using the NODE_OPTIONS environment variable to pass options to node.

shell
NODE_OPTIONS='--trace-deprecation --abort-on-uncaught-exception' ts-node ./index.ts
shell
NODE_OPTIONS='--trace-deprecation --abort-on-uncaught-exception' ts-node ./index.ts

Alternatively, you can invoke node directly and install ts-node via --require/-r

shell
node --trace-deprecation --abort-on-uncaught-exception -r ts-node/register ./index.ts
shell
node --trace-deprecation --abort-on-uncaught-exception -r ts-node/register ./index.ts