The Runtime API

Before a document’s code runs, the reader installs a frozen object at globalThis.idop. It is the only way for a document to reach the reader. There is no endpoint to infer from location.

Methods

Method	Result
idop.runtime.getInfo()	{ runtimeApiVersion, availableCapabilities }
idop.storage.read(path)	{ text }
idop.storage.write(path, text)	{ written: true }
idop.storage.delete(path)	{ deleted: true }
idop.storage.list()	{ paths }
idop.storage.transaction(operations)	{ committed: true } — all or nothing
idop.env.get(id)	{ value } for a declared environment binding
idop.network.request(request)	{ status, headers, body }
idop.ui.requestSave()	asks the reader to show its Save control
idop.ui.requestConfiguration()	asks the reader to show its configuration
idop.host.getInputFile()	the file a viewer was opened for
idop.host.putOutputFile(bytes)	hands an edited copy back to the reader

Every method returns a promise.

Errors

A failure rejects with an Error whose code is stable — for example IDOP-STORAGE-NOT-FOUND, IDOP-NETWORK-ORIGIN-DENIED or IDOP-ENV-MISSING. Branch on code. Never parse message, which is a diagnostic and may be translated or changed.

try {
  const { text } = await idop.storage.read('settings.json');
} catch (error) {
  if (error.code === 'IDOP-STORAGE-NOT-FOUND') useDefaults();
  else throw error;
}

What is deliberately missing

There is no method that returns a secret, lists environment variables, or exports content to an arbitrary destination.