RTTI schemas for the data-shaped operations: for each, the schema of its parameters and of the value its Result carries on success. module.f.mjs holds them, and types.ts pins the declarations in ../node/types.ts to them, so the two cannot drift.

The shared error channel is written once, as result, ioResult and opResult. Only operations whose payload is plain data are here: mkdir, readFile, readdir, writeFile, writeBytes, rm, write, read and resolveFileModule. An operation that takes a callback or an effect is outside what an RTTI schema can describe.

These schemas describe the operations; they are not the ABI of the native runner, which works on VM values directly. The RTTI guide's effects page shows them in use.