diff --git a/techtree-manager/src/main.rs b/techtree-manager/src/main.rs
index 6303643..bfb830a 100644
--- a/techtree-manager/src/main.rs
+++ b/techtree-manager/src/main.rs
@@ -20,7 +20,7 @@ pub struct Context {
     /// URL of the repository page
     pub repo_url: url::Url,
     /// URL of the repository with authentication information attached
-    pub repo_auth_url: url::Url,
+    pub repo_auth_url: Option<url::Url>,
     /// Human readable timestamp of this manager run
     pub timestamp: String,
 }
@@ -42,13 +42,15 @@ async fn run() -> anyhow::Result<()> {
     let timestamp = chrono::Local::now().format("%Y-%m-%d %H:%M:%S").to_string();
     log::info!("Timestamp of this run is {timestamp}");
 
-    let token =
-        std::env::var("GITHUB_TOKEN").context("Failed accessing GITHUB_TOKEN auth token")?;
+    let token = std::env::var("GITHUB_TOKEN").ok();
+    if token.is_none() {
+        log::warn!("No GITHUB_TOKEN, only performing read-only operations!");
+    }
 
-    let server_url = url::Url::parse(
-        &std::env::var("GITHUB_SERVER_URL")
-            .context("Failed reading GITHUB_SERVER_URL server url")?,
-    )
+    let server_url = url::Url::parse(&std::env::var("GITHUB_SERVER_URL").unwrap_or_else(|_e| {
+        log::warn!("Using FAFO URL as a default GITHUB_SERVER_URL!");
+        "https://git.fa-fo.de".to_string()
+    }))
     .context("Failed parsing GITHUB_SERVER_URL as a url")?;
 
     let repo_url = server_url
@@ -57,11 +59,19 @@ async fn run() -> anyhow::Result<()> {
             meta.issue.repository.owner, meta.issue.repository.name
         ))
         .unwrap();
-    let mut repo_auth_url = repo_url.clone();
-    repo_auth_url.set_username("forgejo-actions").unwrap();
-    repo_auth_url.set_password(Some(&token)).unwrap();
 
-    let auth = forgejo_api::Auth::Token(&token);
+    let repo_auth_url = token.as_ref().map(|token| {
+        let mut repo_auth_url = repo_url.clone();
+        repo_auth_url.set_username("forgejo-actions").unwrap();
+        repo_auth_url.set_password(Some(&token)).unwrap();
+        repo_auth_url
+    });
+
+    let auth = if let Some(token) = token.as_ref() {
+        forgejo_api::Auth::Token(token)
+    } else {
+        forgejo_api::Auth::None
+    };
     let forgejo =
         Forgejo::new(auth, server_url).context("Could not create Forgejo API access object")?;
 
@@ -103,9 +113,14 @@ async fn run() -> anyhow::Result<()> {
     let rendered_tree = render::render(&ctx, &tree)
         .await
         .context("Failed to render the techtree")?;
-    render::publish(&ctx, &rendered_tree)
-        .await
-        .context("Failed to publish rendered tree to git")?;
+
+    if token.is_some() {
+        render::publish(&ctx, &rendered_tree)
+            .await
+            .context("Failed to publish rendered tree to git")?;
+    } else {
+        log::warn!("Skipped publishing the rendered tree.");
+    }
 
     // Wiki is disabled because the tree is too big for mermaid to handle
     if false {
@@ -115,6 +130,11 @@ async fn run() -> anyhow::Result<()> {
             .context("Failed to update the techtree wiki page")?;
     }
 
+    if token.is_none() {
+        log::warn!("Not running issue updates without token.");
+        return Ok(());
+    }
+
     'issues: for issue in tree.iter_issues() {
         let subtree = tree.subtree_for_issue(issue).unwrap();
         let hash = subtree.stable_hash();
diff --git a/techtree-manager/src/render.rs b/techtree-manager/src/render.rs
index f3d75b9..f9ebe81 100644
--- a/techtree-manager/src/render.rs
+++ b/techtree-manager/src/render.rs
@@ -103,7 +103,12 @@ pub async fn publish(ctx: &crate::Context, rendered: &RenderedTree) -> anyhow::R
         .arg("push")
         .arg("--force")
         .arg("--quiet")
-        .arg(ctx.repo_auth_url.to_string())
+        .arg(
+            ctx.repo_auth_url
+                .as_ref()
+                .expect("cannot publish without authentication token")
+                .to_string(),
+        )
         .arg("HEAD:refs/heads/render")
         .status()
         .context("Failed to push rendered graph to forgejo repository")?;