diff --git a/src/_internalUtils.ts b/src/_internalUtils.ts
index 0ff34c8..7d99326 100644
--- a/src/_internalUtils.ts
+++ b/src/_internalUtils.ts
@@ -1,8 +1,6 @@
 import { spawnSync, SpawnSyncOptionsWithStringEncoding } from 'child_process';
 import crypto from 'crypto';
 import fs from 'fs';
-import http from 'http';
-import https from 'https';
 import util from 'util';
 import zlib from 'zlib';
 
@@ -43,6 +41,37 @@ export async function retryWithBackoff<T>(job: () => Promise<T>, backoff: number
   return await job();
 }
 
+export const HTTP_BACKOFF = [100, 500, 1000, 1000, 1000, 1000];
+
+async function fetchOk(input: RequestInfo | URL, init?: RequestInit): Promise<Response> {
+  const response = await fetch(input, init);
+  if (!response.ok) {
+    const url = response.url || (input instanceof URL ? input.href : typeof input === 'string' ? input : input.url);
+    const body = await response.text().catch(() => '');
+    throw new Error(response.status + ' ' + url + ' ' + body);
+  }
+  return response;
+}
+
+export async function getJSON<T>(input: RequestInfo | URL, init?: RequestInit, backoff: number[] = HTTP_BACKOFF): Promise<T> {
+  return await retryWithBackoff(async () => {
+    const response = await fetchOk(input, init);
+    return await response.json() as T;
+  }, backoff);
+}
+
+export async function putBuffer(input: RequestInfo | URL, body: Buffer, headers?: HeadersInit, backoff: number[] = HTTP_BACKOFF): Promise<void> {
+  await retryWithBackoff(async () => {
+    const response = await fetchOk(input, {
+      method: 'PUT',
+      headers,
+      body: new Uint8Array(body),
+    });
+    // Read response to ensure it completes.
+    await response.arrayBuffer();
+  }, backoff);
+}
+
 export function shell(command: string, args?: string[], options?: SpawnSyncOptionsWithStringEncoding) {
   try {
     const result = spawnSync(command, args, { encoding: 'utf-8', ...options });
@@ -92,4 +121,4 @@ export function randomUUIDBase62(): string {
   }
   
   return chars.reverse().join('');
-}
\ No newline at end of file
+}
diff --git a/src/fetchTestDurations.ts b/src/fetchTestDurations.ts
index 801d74c..551ca16 100644
--- a/src/fetchTestDurations.ts
+++ b/src/fetchTestDurations.ts
@@ -1,6 +1,6 @@
 import { FlakinessReport } from '@flakiness/flakiness-report';
 import { URL } from 'url';
-import { compressTextAsync, retryWithBackoff, sha1Text } from './_internalUtils.js';
+import { compressTextAsync, getJSON, putBuffer, sha1Text } from './_internalUtils.js';
 import { GithubOIDC } from './githubOIDC.js';
 
 type TestDurationsFetcherOptions = {
@@ -35,9 +35,6 @@ export type FetchTestDurationsOptions = {
   flakinessAccessToken?: string;
 }
 
-// Retry schedule for uploading the report to the presigned URL.
-const HTTP_BACKOFF = [100, 500, 1000, 1000, 1000, 1000];
-
 // The computed historical durations are not ready immediately after submit, so
 // we poll the download URL for up to ~90 seconds before giving up.
 const DOWNLOAD_BACKOFF = [Array(10).fill(1000), Array(10).fill(2000), Array(20).fill(3000)].flat();
@@ -107,19 +104,14 @@ class TestDurationsFetcher {
   private async _api<OUTPUT>(pathname: string, token: string, body?: any): Promise<OUTPUT> {
     const url = new URL(this._options.flakinessEndpoint);
     url.pathname = pathname;
-    return await retryWithBackoff(async () => {
-      const response = await fetch(url, {
-        method: 'POST',
-        headers: {
-          'Authorization': `Bearer ${token}`,
-          'Content-Type': 'application/json',
-        },
-        body: body ? JSON.stringify(body) : undefined,
-      });
-      if (!response.ok)
-        throw new Error(`Failed to fetch ${url}: ${response.status} ${response.statusText}`)
-      return response;
-    }, HTTP_BACKOFF).then(async response => await response.json());
+    return await getJSON<OUTPUT>(url, {
+      method: 'POST',
+      headers: {
+        'Authorization': `Bearer ${token}`,
+        'Content-Type': 'application/json',
+      },
+      body: body ? JSON.stringify(body) : undefined,
+    });
   }
 
   async fetch(): Promise<FlakinessReport.Report> {
@@ -147,12 +139,7 @@ class TestDurationsFetcher {
       createResponse.testDurationsToken,
     );
 
-    return await retryWithBackoff(async () => {
-      const response = await fetch(submitResponse.downloadUrl);
-      if (!response.ok)
-        throw new Error(`Request to ${submitResponse.downloadUrl} failed with ${response.status}`);
-      return response;
-    }, DOWNLOAD_BACKOFF).then(async response => await response.json() as FlakinessReport.Report);
+    return await getJSON<FlakinessReport.Report>(submitResponse.downloadUrl, undefined, DOWNLOAD_BACKOFF);
   }
 
   private async _uploadReport(data: string, uploadUrl: string) {
@@ -162,16 +149,6 @@ class TestDurationsFetcher {
       'Content-Length': Buffer.byteLength(compressed) + '',
       'Content-Encoding': 'br',
     };
-    await retryWithBackoff(async () => {
-      const response = await fetch(uploadUrl, {
-        method: 'PUT',
-        headers,
-        body: Buffer.from(compressed),
-      });
-      if (!response.ok)
-        throw new Error(`Request to ${uploadUrl} failed with ${response.status}`);
-      // Read response to ensure it completes
-      await response.arrayBuffer();
-    }, HTTP_BACKOFF);
+    await putBuffer(uploadUrl, compressed, headers);
   }
 }
diff --git a/src/githubOIDC.ts b/src/githubOIDC.ts
index 2db8174..ca6c524 100644
--- a/src/githubOIDC.ts
+++ b/src/githubOIDC.ts
@@ -1,3 +1,5 @@
+import { getJSON } from './_internalUtils.js';
+
 /**
  * Provides GitHub Actions OIDC (OpenID Connect) token exchange.
  *
@@ -56,19 +58,18 @@ export class GithubOIDC {
     const url = new URL(this._requestUrl);
     url.searchParams.set('audience', flakinessProject);
 
-    const response = await fetch(url, {
-      headers: {
-        'Authorization': `bearer ${this._requestToken}`,
-        'Accept': 'application/json; api-version=2.0',
-      },
-    });
-
-    if (!response.ok) {
-      const body = await response.text().catch(() => '');
-      throw new Error(`Failed to request GitHub OIDC token: ${response.status} ${body}`);
+    let json: { value?: string };
+    try {
+      json = await getJSON<{ value?: string }>(url, {
+        headers: {
+          'Authorization': `bearer ${this._requestToken}`,
+          'Accept': 'application/json; api-version=2.0',
+        },
+      });
+    } catch (error: any) {
+      throw new Error(`Failed to request GitHub OIDC token: ${error.message || String(error)}`);
     }
 
-    const json = await response.json() as { value?: string };
     if (!json.value)
       throw new Error('GitHub OIDC token response did not contain a token value.');
 
diff --git a/src/uploadReport.ts b/src/uploadReport.ts
index 6f29a8c..365ae5f 100644
--- a/src/uploadReport.ts
+++ b/src/uploadReport.ts
@@ -3,7 +3,7 @@ import assert from 'assert';
 import fs from 'fs';
 import { URL } from 'url';
 import { GithubOIDC } from './githubOIDC.js';
-import { compressTextAsync, retryWithBackoff, sha1File, sha1Text } from './_internalUtils.js';
+import { compressTextAsync, getJSON, putBuffer, sha1File, sha1Text } from './_internalUtils.js';
 
 type ReportUploaderOptions = {
   flakinessEndpoint: string;
@@ -293,8 +293,6 @@ export async function uploadReport(
   }
 }
 
-const HTTP_BACKOFF = [100, 500, 1000, 1000, 1000, 1000];
-
 class ReportUpload {
   private _report: FlakinessReport.Report;
   private _attachments: Attachment[];
@@ -309,23 +307,25 @@ class ReportUpload {
   private async _api<OUTPUT>(pathname: string, token: string, body?: any): Promise<{ result?: OUTPUT, error?: string }> {
     const url = new URL(this._options.flakinessEndpoint);
     url.pathname = pathname;
-    return await fetch(url, {
-      method: 'POST',
-      headers: {
-        'Authorization': `Bearer ${token}`,
-        'Content-Type': 'application/json',
-      },
-      body: body ? JSON.stringify(body) : undefined,
-    }).then(async response => !response.ok ? {
-      result: undefined,
-      error: response.status + ' ' + url.href + ' ' + await response.text(),
-    } : {
-      result: await response.json() as OUTPUT,
-      error: undefined,
-    }).catch(error => ({
-      result: undefined,
-      error,
-    }));
+    try {
+      const result = await getJSON<OUTPUT>(url, {
+        method: 'POST',
+        headers: {
+          'Authorization': `Bearer ${token}`,
+          'Content-Type': 'application/json',
+        },
+        body: body ? JSON.stringify(body) : undefined,
+      });
+      return {
+        result,
+        error: undefined,
+      };
+    } catch (error: any) {
+      return {
+        result: undefined,
+        error: error instanceof Error ? error.message : String(error),
+      };
+    }
   }
 
   async upload(): Promise<{ success: false, message?: string } | { success: true, reportUrl: string }> {
@@ -370,18 +370,7 @@ class ReportUpload {
       'Content-Length': Buffer.byteLength(compressed) + '',
       'Content-Encoding': 'br',
     };
-    await retryWithBackoff(async () => {
-      const response = await fetch(uploadUrl, {
-        method: 'PUT',
-        headers,
-        body: Buffer.from(compressed),
-      });
-      if (!response.ok) {
-        throw new Error(`Request to ${uploadUrl} failed with ${response.status}`);
-      }
-      // Read response to ensure it completes
-      await response.arrayBuffer();
-    }, HTTP_BACKOFF);
+    await putBuffer(uploadUrl, compressed, headers);
   }
 
   private async _uploadAttachment(attachment: Attachment, uploadUrl: string) {
@@ -393,22 +382,11 @@ class ReportUpload {
     ;
     // Stream file only if there's attachment path and we should NOT compress it.
     if (!compressable && attachment.type === 'file') {
-      await retryWithBackoff(async () => {
-        const fileBuffer = await fs.promises.readFile(attachment.path);
-        const response = await fetch(uploadUrl, {
-          method: 'PUT',
-          headers: {
-            'Content-Type': attachment.contentType,
-            'Content-Length': fileBuffer.length + '',
-          },
-          body: new Uint8Array(fileBuffer),
-        });
-        if (!response.ok) {
-          throw new Error(`Request to ${uploadUrl} failed with ${response.status}`);
-        }
-        // Read response to ensure it completes
-        await response.arrayBuffer();
-      }, HTTP_BACKOFF);
+      const fileBuffer = await fs.promises.readFile(attachment.path);
+      await putBuffer(uploadUrl, fileBuffer, {
+          'Content-Type': attachment.contentType,
+          'Content-Length': fileBuffer.length + '',
+      });
       return;
     }
     let buffer = attachment.type === 'buffer' ? attachment.body : await fs.promises.readFile(attachment.path);
@@ -427,17 +405,6 @@ class ReportUpload {
       headers['Content-Encoding'] = encoding;
     }
 
-    await retryWithBackoff(async () => {
-      const response = await fetch(uploadUrl, {
-        method: 'PUT',
-        headers,
-        body: new Uint8Array(buffer),
-      });
-      if (!response.ok) {
-        throw new Error(`Request to ${uploadUrl} failed with ${response.status}`);
-      }
-      // Read response to ensure it completes
-      await response.arrayBuffer();
-    }, HTTP_BACKOFF);
+    await putBuffer(uploadUrl, buffer, headers);
   }
 }