diff --git a/src/geotiff.js b/src/geotiff.js
index 842da8a2..17349a41 100644
--- a/src/geotiff.js
+++ b/src/geotiff.js
@@ -4,10 +4,11 @@ import DataView64 from './dataview64.js';
 import DataSlice from './dataslice.js';
 import Pool from './pool.js';
 
-import { makeRemoteSource } from './source/remote.js';
+import { makeRemoteSource, makeCustomSource } from './source/remote.js';
 import { makeBufferSource } from './source/arraybuffer.js';
 import { makeFileReaderSource } from './source/filereader.js';
 import { makeFileSource } from './source/file.js';
+import { BaseClient, BaseResponse } from './source/client/base.js';
 
 import { fieldTypes, fieldTagNames, arrayFields, geoKeyNames } from './globals.js';
 import { writeGeotiff } from './geotiffwriter.js';
@@ -684,6 +685,19 @@ export async function fromUrl(url, options = {}, signal) {
   return GeoTIFF.fromSource(makeRemoteSource(url, options), signal);
 }
 
+/**
+ * Creates a new GeoTIFF from a custom {@link BaseClient}.
+ * @param {BaseClient} client The client.
+ * @param {object} [options] Additional options to pass to the source.
+ *                           See {@link makeRemoteSource} for details.
+ * @param {AbortSignal} [signal] An AbortSignal that may be signalled if the request is
+ *                               to be aborted
+ * @returns {Promise<GeoTIFF>} The resulting GeoTIFF file.
+ */
+export async function fromCustomClient(client, options = {}, signal) {
+  return GeoTIFF.fromSource(makeCustomSource(client, options), signal);
+}
+
 /**
  * Construct a new GeoTIFF from an
  * [ArrayBuffer]{@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer}.
@@ -757,3 +771,4 @@ export function writeArrayBuffer(values, metadata) {
 
 export { Pool };
 export { GeoTIFFImage };
+export { BaseClient, BaseResponse };
diff --git a/src/source/remote.js b/src/source/remote.js
index 2501e0b0..be752928 100644
--- a/src/source/remote.js
+++ b/src/source/remote.js
@@ -175,6 +175,11 @@ export function makeHttpSource(url, { headers = {}, maxRanges = 0, allowFullFile
   return maybeWrapInBlockedSource(source, blockOptions);
 }
 
+export function makeCustomSource(client, { headers = {}, maxRanges = 0, allowFullFile = false, ...blockOptions } = {}) {
+  const source = new RemoteSource(client, headers, maxRanges, allowFullFile);
+  return maybeWrapInBlockedSource(source, blockOptions);
+}
+
 /**
  *
  * @param {string} url