diff --git a/dist/index.js b/dist/index.js
index 8cbfb72..efd00c1 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1283,15 +1283,36 @@ class GitHubHelper {
         if (token) {
             options.auth = `${token}`;
         }
-        if (githubServerHostname !== 'github.com') {
-            options.baseUrl = `https://${githubServerHostname}/api/v1`;
-        }
-        else {
-            options.baseUrl = 'https://api.github.com';
-        }
+        options.baseUrl = this.determineApiPath(githubServerHostname);
         options.throttle = octokit_client_1.throttleOptions;
         this.octokit = new octokit_client_1.Octokit(options);
     }
+    determineApiPath(hostname) {
+        if (hostname === 'github.com') {
+            return "https://api.github.com";
+        }
+        const baseUrl = `https://${hostname}`;
+        const possiblePaths = ['/api/v4/version', '/api/forgejo/v1/version', '/api/v1/version'];
+        for (const path of possiblePaths) {
+            try {
+                const url = `${baseUrl}${path}`;
+                const xhr = new XMLHttpRequest();
+                xhr.open('GET', url, false); // false makes it synchronous
+                xhr.setRequestHeader('Accept', 'application/json');
+                xhr.send();
+                if (xhr.status === 200 || xhr.status === 401 || xhr.status === 403) {
+                    const contentType = xhr.getResponseHeader('Content-Type') || '';
+                    if (contentType.includes('application/json')) {
+                        return path.includes('/version') ? url.replace('/version', '') : url;
+                    }
+                }
+            }
+            catch (error) {
+                // Try the next path
+            }
+        }
+        throw new Error(`Unable to determine API base URL for hostname: ${hostname}`);
+    }
     parseRepository(repository) {
         const [owner, repo] = repository.split('/');
         return {
diff --git a/src/github-helper.ts b/src/github-helper.ts
index 82a9296..1a979f2 100644
--- a/src/github-helper.ts
+++ b/src/github-helper.ts
@@ -46,15 +46,43 @@ export class GitHubHelper {
     if (token) {
       options.auth = `${token}`
     }
-    if (githubServerHostname !== 'github.com') {
-      options.baseUrl = `https://${githubServerHostname}/api/v3`
-    } else {
-      options.baseUrl = 'https://api.github.com'
-    }
+    options.baseUrl = this.determineApiPath(githubServerHostname)
     options.throttle = throttleOptions
     this.octokit = new Octokit(options)
   }
 
+  private determineApiPath(hostname: string): string {
+    if (hostname === 'github.com') {
+      return "https://api.github.com"
+    }
+
+    const baseUrl = `https://${hostname}`
+    const possiblePaths = ['/api/v4/version', '/api/forgejo/v1/version', '/api/v1/version']
+
+    for (const path of possiblePaths) {
+      try {
+        const url = `${baseUrl}${path}`
+
+        const xhr = new XMLHttpRequest();
+        xhr.open('GET', url, false); // false makes it synchronous
+        xhr.setRequestHeader('Accept', 'application/json');
+        xhr.send();
+
+        if (xhr.status === 200 || xhr.status === 401 || xhr.status === 403) {
+            const contentType = xhr.getResponseHeader('Content-Type') || '';
+            if (contentType.includes('application/json')) {
+                return path.includes('/version') ? url.replace('/version', '') : url;
+            }
+        }
+      } catch (error) {
+        // Try the next path
+        core.warning(`API url '${baseUrl}${path}` failes with ${error});
+      }
+    }
+
+    throw new Error(`Unable to determine API base URL for hostname: ${hostname}`)
+  }
+
   private parseRepository(repository: string): Repository {
     const [owner, repo] = repository.split('/')
     return {
@@ -403,3 +431,4 @@ export class GitHubHelper {
     })
   }
 }
+