---
name: kkrpc-migration
description: Use when migrating kkrpc projects across breaking stable API changes, replacing classic IoInterface/*IO adapters, next entries, validation/interceptor options, transport imports, or opt-in streaming/remote-reference entries.
version: 1.0.0
license: MIT
metadata:
  author: kkrpc
  domain: typescript-rpc
  tags:
    - rpc
    - migration
    - typescript
    - kkrpc
    - transport
compatibility: Migrates kkrpc 0.7.x and temporary vNext code to kkrpc 1.0 stable APIs.
---

# kkrpc 1.0 Migration

Use this skill to migrate applications from kkrpc 0.7.x or temporary `kkrpc/next` APIs to the stable 1.0 API.

The 1.0 public API is native `Transport<RPCMessage>` based. Do not preserve the classic `IoInterface` adapter model, public `*IO` classes, `classic-compat`, `next/io`, `browser-lite`, `browser-mini`, or `electron-ipc` imports.

Canonical user documentation: `docs/src/content/docs/guides/migration-1-0.md`.
For the slim-core feature split, also check `docs/src/content/docs/guides/migration-0-1-to-0-2.md`.

## Migration Workflow

1. Inspect package versions and imports.
2. Search for old API usage.
3. Replace package entries and transport imports.
4. Replace channel setup with `wrap()`, `expose()`, or native `RPCChannel`.
5. Replace classic IO adapters with native transport factories.
6. Replace validation and middleware options with plugins.
7. Move SuperJSON to explicit codec composition.
8. Run type checks, tests, and old-API searches.

## Search Patterns

Run these searches before editing and again before finishing:

```bash
rg 'kkrpc/next|next/io|classic-compat|IoInterface|IoMessage|RPCValidators|kkrpc/browser-lite|kkrpc/browser-mini|kkrpc/electron-ipc'
rg '[A-Za-z0-9_]+IO\b'
rg 'validators\s*:|interceptors\s*:'
```

The `*IO` search may find application names. Review matches manually and only migrate kkrpc classic adapter usage.

## Entry Mapping

| Old import | New import |
| --- | --- |
| `kkrpc/next` | `kkrpc` |
| `kkrpc/next/transport` | `kkrpc/transport` |
| `kkrpc/next/codecs` | `kkrpc/codecs` |
| `kkrpc/next/plugins` | `kkrpc/plugins` |
| `kkrpc/next/validation` | `kkrpc/validation` |
| `kkrpc/next/middleware` | `kkrpc/middleware` |
| `kkrpc/next/superjson` | `kkrpc/superjson` |
| async iterable APIs from `kkrpc` | `kkrpc/streaming` |
| callback-return/object-handle APIs from `kkrpc` | `kkrpc/remote-refs` |
| `kkrpc/next/worker` | `kkrpc/worker` |
| `kkrpc/next/stdio` | `kkrpc/stdio` |
| `kkrpc/browser-lite` | `kkrpc` or `kkrpc/browser` |
| `kkrpc/browser-mini` | `kkrpc` or `kkrpc/browser` |
| `kkrpc/electron-ipc` | `kkrpc/electron` |

Runtime transports must not be imported from the main `kkrpc` entry. Use explicit subpaths.

Async iterable streaming and request/response remote references must also use explicit subpaths. The default `kkrpc` entry is the slim request/response core.

## Core API Patterns

### Client-only proxy

Use `wrap()` when this side only calls a remote API.

```typescript
import { wrap } from "kkrpc"
import { webSocketClientTransport } from "kkrpc/ws"

const api = wrap<RemoteAPI>(webSocketClientTransport({ url: "ws://localhost:3000" }))
```

If the proxy has a bounded lifetime, dispose it explicitly:

```typescript
import { dispose } from "kkrpc"

dispose(api)
```

### Server-only API

Use `expose()` when this side only publishes a local API.

```typescript
import { expose } from "kkrpc"

const controller = expose(localAPI, transport)
controller.dispose()
```

### Bidirectional endpoint

Use native `RPCChannel` when both sides expose APIs.

```typescript
import { RPCChannel } from "kkrpc"

const channel = new RPCChannel<LocalAPI, RemoteAPI>(transport, { expose: localAPI })
const remote = channel.getAPI()
channel.destroy()
```

The generic order is local API first, remote API second.

## Transport Mapping

| Boundary | Native 1.0 helper |
| --- | --- |
| Web Worker parent | `workerTransport()` from `kkrpc/worker` |
| Web Worker global | `workerSelfTransport()` from `kkrpc/worker` |
| Node stdio | `nodeStdioTransport()` from `kkrpc/stdio` |
| Generic stdio JSON | `stdioJsonTransport()` from `kkrpc/stdio` |
| HTTP client | `httpClientTransport()` from `kkrpc/http` |
| HTTP server | `createHttpHandler()` from `kkrpc/http` |
| WebSocket socket | `webSocketTransport()` from `kkrpc/ws` |
| WebSocket client | `webSocketClientTransport()` from `kkrpc/ws` |
| Hono WebSocket | `createHonoWebSocketHandler()` or `honoWebSocketTransport()` from `kkrpc/ws/hono` |
| Elysia WebSocket | `createElysiaWebSocketHandler()` or `elysiaWebSocketTransport()` from `kkrpc/ws/elysia` |
| iframe parent | `iframeParentTransport()` from `kkrpc/iframe` |
| iframe child | `iframeChildTransport()` from `kkrpc/iframe` |
| Chrome extension port | `chromePortTransport()` from `kkrpc/chrome-extension` |
| Electron IPC | `electronIpcTransport()` from `kkrpc/electron` |
| Electron utility process | `electronUtilityProcessTransport()` or `electronUtilityProcessChildTransport()` from `kkrpc/electron` |
| Tauri shell child process | `tauriShellStdioTransport()` from `kkrpc/tauri` |
| Socket.IO | `socketIoTransport()` from `kkrpc/socketio` |
| RabbitMQ | `rabbitMqTransport()` from `kkrpc/rabbitmq` |
| Kafka | `kafkaTransport()` from `kkrpc/kafka` |
| Redis Streams | `redisStreamsTransport()` from `kkrpc/redis-streams` |
| NATS | `natsTransport()` from `kkrpc/nats` |

## HTTP Guardrail

HTTP is unary request/response in 1.0. Do not migrate callback-heavy, subscription, streaming-progress, remote-reference, raw-function, or server-push code to `kkrpc/http`. Use WebSocket or another evented transport for those boundaries.

When migrating remote references to RabbitMQ, Kafka, Redis Streams, or NATS, configure `remotePeerId`. Broadcast bus mode is for fan-out messages and does not advertise remote-reference support.

Remote proxies decoded from one channel are not portable across another channel. Replace implicit proxy forwarding with an explicit bridge method if an old design depended on that behavior.

## Validation Migration

Replace classic `validators` options with `validationPlugin()`.

```typescript
import { expose } from "kkrpc"
import { validationPlugin } from "kkrpc/validation"

const validators = {
	"math.add": {
		input: argsSchema,
		output: resultSchema
	}
}

expose(api, transport, {
	plugins: [validationPlugin(validators)]
})
```

If preserving an existing validator map is simpler, pass that map to `validationPlugin()` instead of rewriting the API around `defineMethod()`.

## Middleware Migration

Replace classic `interceptors` options with `middlewarePlugin()`.

```typescript
import { middlewarePlugin, type RPCInterceptor } from "kkrpc/middleware"

const logger: RPCInterceptor = async (ctx, next) => {
	console.log(ctx.method)
	return next()
}

const plugins = [middlewarePlugin([logger])]
```

Install the plugin through `wrap()`, `expose()`, or `RPCChannel` options.

## SuperJSON Migration

SuperJSON is not a core import. Use `kkrpc/superjson` only where a transport needs richer value encoding.

```typescript
import { createTransport } from "kkrpc/transport"
import { superJsonCodec } from "kkrpc/superjson"

const transport = createTransport({ platform, codec: superJsonCodec() })
```

## Transferables

Use `transfer()` from `kkrpc` only for transports that support transferable ownership, such as Web Workers.

```typescript
import { transfer } from "kkrpc"

await api.process(transfer(buffer, [buffer]))
```

Do not assume transfer support for HTTP, stdio, or message-bus transports.

## Guardrails

- Do not add backward compatibility aliases for removed public APIs.
- Do not reintroduce `IoInterface`, `IoMessage`, or public `*IO` classes.
- Do not import runtime-specific transports from `kkrpc`.
- Do not pull optional peers into browser-safe entries.
- Do not claim HTTP supports callbacks or bidirectional calls.
- Do not leave async iterable APIs on the default `kkrpc` entry; use `kkrpc/streaming`.
- Do not leave callback-return or object-handle APIs on the default `kkrpc` entry; use `kkrpc/remote-refs` and explicit `proxy(value)` markers.
- Do not rely on unmarked nested functions crossing by raw identity; `kkrpc/remote-refs` rejects them.
- Do not edit generated `dist` or Typedoc output while migrating this repository.

## Verification

For this repository, run:

```bash
pnpm --filter kkrpc check-types
pnpm --filter kkrpc test
pnpm --filter "./examples/*" check-types
```

For downstream projects, run the project type check, unit tests, and at least one integration test for each migrated transport boundary.

Before declaring migration complete, re-run the old API searches and verify that remaining matches are documentation, intentional compatibility notes, or unrelated false positives.