Transport

DefaultHttpTransport

The built-in HTTP transport implements DatafnRemoteAdapter and handles communication with a DataFn server over HTTP.

When you provide sync.remote in the client config, the default transport is created automatically. You can also inject a custom adapter via sync.remoteAdapter.

DatafnRemoteAdapter

interface DatafnRemoteAdapter {
  query(q: unknown): Promise<unknown>;
  mutation(m: unknown): Promise<unknown>;
  transact(t: unknown): Promise<unknown>;
  seed(payload: unknown): Promise<unknown>;
  clone(payload: unknown): Promise<unknown>;
  pull(payload: unknown): Promise<unknown>;
  push(payload: unknown): Promise<unknown>;
  reconcile(payload: unknown): Promise<unknown>;
}

Each method posts JSON to the corresponding server endpoint and returns the response envelope.

Endpoint Mapping

Timeout and Error Behavior

The default HTTP transport does not expose a built-in timeout option. It forwards an optional signal only for query() payloads and maps AbortError to a DFQL_ABORTED envelope.

Other network failures are thrown as errors, and non-OK HTTP responses throw unless the response body is already a DataFn envelope.

Extension Transport

For browser extensions, createExtensionTransport creates a remote adapter that proxies calls over a message bus (e.g., browser.runtime.sendMessage).

import { createExtensionTransport } from "@datafn/client/extension";

const adapter = createExtensionTransport(messageBus, {
  timeout: 30000, // per-request timeout in ms
});

const client = createDatafnClient({
  schema,
  clientId: "ext-client",
  sync: { remoteAdapter: adapter },
});

The extension transport uses an RPC protocol with request/response correlation by ID. Pending requests that do not receive a response within the timeout are rejected with a TIMEOUT error.