---
title: "DF0075: No RPC Transport On This Runtime"
description: "On Bun/Deno a shared server needs crossws Node adapter and SSE is disabled, so no RPC transport is advertised."
canonical_url: "https://devfra.me/errors/df0075"
---
# DF0075: No RPC Transport On This Runtime

> On Bun/Deno a shared server needs crossws Node adapter and SSE is disabled, so no RPC transport is advertised.

## Message

> On  the shared server's WebSocket upgrade needs crossws's Node adapter, which refuses to run off Node, and SSE is disabled, so this instance advertises no RPC transport at all.

## Cause

Sharing a host's `node:http` server (the `server` tier) drives the WebSocket upgrade through crossws's Node adapter, which runs only on Node. On Bun and Deno the socket falls back to the SSE endpoint, but here `sse: false` turned that endpoint off too, so the instance has no way for a client to reach its RPC surface.

## Example

```ts
import { initHub } from '@devframes/hub/initiate'

// Running on Bun/Deno, sharing the host's node:http server:
const hub = initHub({
  server: viteHttpServer,
  sse: false, // ✗ removes the only transport left on Bun/Deno
})
```

## Fix

Keep the SSE endpoint enabled (drop `sse: false`) so clients connect over it on Bun/Deno, or move the socket to a side-car: `ws: { sidecar: true }` binds the native WebSocket adapter (`Bun.serve` / `Deno.serve`) on its own port, where a real WebSocket works.

## Source

- [`packages/devframe/src/node/instance-shell.ts`](https://github.com/devframes/devframe/blob/main/packages/devframe/src/node/instance-shell.ts): the shared instance shell warns this when a shared-server WebSocket binding falls back on Bun/Deno and the SSE endpoint is disabled, for both `initDevframe` and `initHub`.


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