From b7d22868a16241d20972869b342d49c7244505ed Mon Sep 17 00:00:00 2001
From: Chris Bala <chrbala@gmail.com>
Date: Mon, 16 Feb 2026 02:18:41 -0800
Subject: [PATCH 1/2] Add environment variables for external files

---
 .../fingerprint-generator/src/fingerprint-generator.ts    | 2 +-
 packages/fingerprint-injector/src/fingerprint-injector.ts | 8 ++++++--
 .../generative-bayesian-network/src/bayesian-network.ts   | 4 ++++
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/packages/fingerprint-generator/src/fingerprint-generator.ts b/packages/fingerprint-generator/src/fingerprint-generator.ts
index c567e271..a840c352 100644
--- a/packages/fingerprint-generator/src/fingerprint-generator.ts
+++ b/packages/fingerprint-generator/src/fingerprint-generator.ts
@@ -141,7 +141,7 @@ export class FingerprintGenerator extends HeaderGenerator {
             slim: options.slim,
         };
         this.fingerprintGeneratorNetwork = new BayesianNetwork({
-            path: `${__dirname}/data_files/fingerprint-network-definition.zip`,
+            path: process.env.FINGERPRINT_NETWORK_DEFINITION_PATH || `${__dirname}/data_files/fingerprint-network-definition.zip`,
         });
     }
 
diff --git a/packages/fingerprint-injector/src/fingerprint-injector.ts b/packages/fingerprint-injector/src/fingerprint-injector.ts
index 41a0353d..6ba2c3e3 100644
--- a/packages/fingerprint-injector/src/fingerprint-injector.ts
+++ b/packages/fingerprint-injector/src/fingerprint-injector.ts
@@ -1,4 +1,4 @@
-import { readFileSync } from 'fs';
+import { readFileSync, existsSync } from 'fs';
 
 import {
     BrowserFingerprintWithHeaders,
@@ -310,8 +310,12 @@ export class FingerprintInjector {
      * causing errors when executing it in the browser.
      */
     private _loadUtils(): string {
+        const path = process.env.FINGERPRINT_INJECTOR_UTILS_PATH || `${__dirname}/utils.js`
+        if (!existsSync(path)) {
+            throw new Error(`Unable to find ${path}`);
+        }
         // path.join would be better here, but Vercel's build system doesn't like it (https://github.com/apify/fingerprint-suite/issues/135)
-        const utilsJs = readFileSync(`${__dirname}/utils.js`);
+        const utilsJs = readFileSync(path);
         return `\n${utilsJs}\n`;
     }
 
diff --git a/packages/generative-bayesian-network/src/bayesian-network.ts b/packages/generative-bayesian-network/src/bayesian-network.ts
index 80be3fd2..a7114f1b 100644
--- a/packages/generative-bayesian-network/src/bayesian-network.ts
+++ b/packages/generative-bayesian-network/src/bayesian-network.ts
@@ -1,4 +1,5 @@
 import AdmZip = require('adm-zip');
+import { existsSync } from 'fs';
 
 import { BayesianNode } from './bayesian-node';
 
@@ -13,6 +14,9 @@ export class BayesianNetwork {
     private nodesByName: Record<string, BayesianNode> = {};
 
     constructor({ path }: { path: string }) {
+        if (!existsSync(path)) {
+            throw new Error(`Unable to find ${path}`);
+        }
         const zip = new AdmZip(path);
         const zipEntries = zip.getEntries();
 

From 5e046e47633036b0bcc1f26db78af6c99a8f8cc6 Mon Sep 17 00:00:00 2001
From: Chris Bala <chrbala@gmail.com>
Date: Mon, 16 Feb 2026 02:25:26 -0800
Subject: [PATCH 2/2] Update readme

---
 README.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/README.md b/README.md
index ad1bc943..abcf9c3f 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,15 @@ import { newInjectedPage } from 'fingerprint-injector';
 })();
 ```
 
+## Environment Variables
+
+The following environment variables can be used to customize file paths used by the fingerprinting tools:
+
+- `FINGERPRINT_NETWORK_DEFINITION_PATH`: Custom path to the fingerprint network definition zip file. If not set, defaults to the bundled file in `fingerprint-generator`. The default file can be found at `fingerprint-generator/data_files/fingerprint-network-definition.zip`.
+- `FINGERPRINT_INJECTOR_UTILS_PATH`: Custom path to the fingerprint injector utils.js file. If not set, defaults to the bundled file in `fingerprint-injector`. The default file can be found at `fingerprint-injector/utils.js`.
+
+You can copy these files to custom locations and provide their paths via these environment variables if needed.
+
 ## Support
 
 If you find any bug or issue with any of the fingerprinting tools, please [submit an issue on GitHub](https://github.com/apify/fingerprint-suite/issues).