The Dock's raw imports are stringly. The SDK turns them into idiomatic, typed, cap-scoped calls so you never hand-build JSON or parse a result string. There's a Rust crate and a JS module.

In Rust, you list the exact capabilities your component imports — that list is the cap-scoping (it must match your WIT world and your granted #+CAPS):

dock::bind!(bindings, llm, vfs, parallel);

let reply = dock::llm::ask("In five words: what is a toolkit?")?;
let rows: Vec<Row> = dock::vfs::query("select * from items")?;
let outs = dock::parallel::map("resize", &frames)?;   // fan across isolated instances
dock::out(json!({ "reply": reply }))

Every fallible call returns a Result — a host error becomes an Err, never a silently-corrupt value. Output is one call: dock::out(value) replaces hand-rolled JSON.

In JS, the same surface over jco-generated bindings:

import { bind, out } from "dock";
const dock = bind(imports);          // only the caps your world imports resolve
const reply = dock.llm.ask("...");
return out({ reply });

• The capabilities themselves: The Dock & capabilities

• Full API: Dock SDK API