Limitations

Node.js is not included. Node.js 16.9 or later must be installed, and Node.js 21 or later is needed to return BigInt values. See Configuring the Node.js process.
Arguments and results are serialized as JSON. Use JSValue to pass values that JSON cannot represent, and JSReference to keep values in the Node.js process. See Arguments and results and Keeping values in Node.js.
A message is limited to the maximum length of a JavaScript string (about 512 million UTF-16 characters). A larger message fails its call.
JSValue and JSReference can only be used in the arguments of a call. A JsonNode created from them cannot be serialized or cloned, and they cannot be members of objects serialized using reflection.
JavaScript code cannot call back into .NET.
Canceling a call does not stop its JavaScript code. Set UnresponsiveTimeout to kill the process when the code blocks its event loop. See Cancellation and timeouts.
A synchronous infinite loop blocks all the other calls, or all the other calls of its worker thread with WorkerThreads. Disposing the host kills the process.
A module is loaded once per process. A change to its file has no effect until a new host is started. See Calling modules.
JavaScript code must not read from process.stdin, which is closed once the process has started.
The library is not a sandbox. See Security.