diff --git a/Cargo.lock b/Cargo.lock
index 242c5e7..179c210 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3015,7 +3015,7 @@ dependencies = [
 
 [[package]]
 name = "rustguac"
-version = "0.6.0"
+version = "0.6.1"
 dependencies = [
  "aes",
  "axum",
diff --git a/Cargo.toml b/Cargo.toml
index 35be8ea..c1fbc3a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rustguac"
-version = "0.6.0"
+version = "0.6.1"
 edition = "2021"
 description = "Lightweight Rust replacement for Apache Guacamole client"
 
diff --git a/docs/configuration.md b/docs/configuration.md
index 1ca536d..c279df8 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -95,6 +95,10 @@ Enables the Vault-backed address book. Requires `VAULT_SECRET_ID` environment va
 | `base_path` | `rustguac` | Base path under the mount |
 | `namespace` | — | Vault Enterprise / OpenBao namespace |
 | `instance_name` | — | Instance name for instance-scoped entries |
+| `tls_skip_verify` | `false` | Skip TLS certificate verification (dev only) |
+| `ca_cert` | — | Path to custom CA certificate (PEM) for verifying the Vault server |
+| `client_cert` | — | Path to client certificate (PEM) for mTLS |
+| `client_key` | — | Path to client private key (PEM) for mTLS (required if `client_cert` is set) |
 
 ## `[drive]` section
 
diff --git a/docs/integrations.md b/docs/integrations.md
index b515f21..4e2f2df 100644
--- a/docs/integrations.md
+++ b/docs/integrations.md
@@ -174,6 +174,35 @@ echo 'VAULT_SECRET_ID=<secret_id>' > /opt/rustguac/env
 chmod 600 /opt/rustguac/env
 ```
 
+### mTLS (client certificate authentication)
+
+If your Vault or OpenBao server requires mutual TLS (client certificates), add the certificate paths to the `[vault]` section:
+
+```toml
+[vault]
+addr = "https://openbao.example.com:8200"
+role_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+ca_cert = "/opt/rustguac/certs/vault-ca.pem"
+client_cert = "/opt/rustguac/certs/vault-client.pem"
+client_key = "/opt/rustguac/certs/vault-client-key.pem"
+```
+
+| Field | Description |
+|-------|-------------|
+| `ca_cert` | Custom CA certificate (PEM) for verifying the Vault server. Use this when Vault uses a private or self-signed CA. |
+| `client_cert` | Client certificate (PEM) presented to Vault for mTLS. |
+| `client_key` | Client private key (PEM). Required when `client_cert` is set. |
+
+Ensure the certificate files are readable by the `rustguac` system user and have restrictive permissions:
+
+```bash
+mkdir -p /opt/rustguac/certs
+cp ca.pem client.pem client-key.pem /opt/rustguac/certs/
+chown rustguac:rustguac /opt/rustguac/certs/*
+chmod 600 /opt/rustguac/certs/client-key.pem
+chmod 644 /opt/rustguac/certs/ca.pem /opt/rustguac/certs/client.pem
+```
+
 ### KV v2 path structure
 
 | Path | Description |
diff --git a/src/api.rs b/src/api.rs
index dc7faaa..933e964 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -2500,3 +2500,63 @@ fn html_escape(s: &str) -> String {
         .replace('"', "&quot;")
         .replace('\'', "&#x27;")
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::path::Path;
+
+    #[test]
+    fn test_html_escape_special_chars() {
+        assert_eq!(html_escape("<script>"), "&lt;script&gt;");
+        assert_eq!(html_escape("a&b"), "a&amp;b");
+        assert_eq!(html_escape(r#"x"y"#), "x&quot;y");
+        assert_eq!(html_escape("it's"), "it&#x27;s");
+    }
+
+    #[test]
+    fn test_html_escape_passthrough() {
+        assert_eq!(html_escape("hello world"), "hello world");
+        assert_eq!(html_escape(""), "");
+    }
+
+    #[test]
+    fn test_html_escape_multiple() {
+        assert_eq!(
+            html_escape(r#"<a href="x">&</a>"#),
+            "&lt;a href=&quot;x&quot;&gt;&amp;&lt;/a&gt;"
+        );
+    }
+
+    #[test]
+    fn test_safe_recording_name_valid() {
+        assert!(is_safe_recording_name(
+            "session-abc123.guac",
+            Path::new("/tmp")
+        ));
+        assert!(is_safe_recording_name(
+            "2024-01-01_recording.guac",
+            Path::new("/recordings")
+        ));
+    }
+
+    #[test]
+    fn test_safe_recording_name_no_guac_extension() {
+        assert!(!is_safe_recording_name("session.mp4", Path::new("/tmp")));
+        assert!(!is_safe_recording_name("session", Path::new("/tmp")));
+    }
+
+    #[test]
+    fn test_safe_recording_name_path_traversal() {
+        assert!(!is_safe_recording_name(
+            "../etc/passwd.guac",
+            Path::new("/tmp")
+        ));
+        assert!(!is_safe_recording_name("foo/bar.guac", Path::new("/tmp")));
+        assert!(!is_safe_recording_name("foo\\bar.guac", Path::new("/tmp")));
+        assert!(!is_safe_recording_name(
+            "..%2F..%2Fetc.guac",
+            Path::new("/tmp")
+        ));
+    }
+}
diff --git a/src/auth.rs b/src/auth.rs
index d01f235..f310e9b 100644
--- a/src/auth.rs
+++ b/src/auth.rs
@@ -394,3 +394,104 @@ pub async fn optional_auth(
     // No credentials — pass through without identity
     next.run(request).await
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_role_level_hierarchy() {
+        assert_eq!(role_level("admin"), 4);
+        assert_eq!(role_level("poweruser"), 3);
+        assert_eq!(role_level("operator"), 2);
+        assert_eq!(role_level("viewer"), 1);
+        assert_eq!(role_level("unknown"), 0);
+        assert_eq!(role_level(""), 0);
+    }
+
+    #[test]
+    fn test_role_level_ordering() {
+        assert!(role_level("admin") > role_level("poweruser"));
+        assert!(role_level("poweruser") > role_level("operator"));
+        assert!(role_level("operator") > role_level("viewer"));
+        assert!(role_level("viewer") > role_level("garbage"));
+    }
+
+    #[test]
+    fn test_compute_effective_role_no_cap() {
+        assert_eq!(compute_effective_role("admin", &None), "admin");
+        assert_eq!(compute_effective_role("viewer", &None), "viewer");
+    }
+
+    #[test]
+    fn test_compute_effective_role_capped() {
+        let cap = Some("operator".into());
+        assert_eq!(compute_effective_role("admin", &cap), "operator");
+        assert_eq!(compute_effective_role("poweruser", &cap), "operator");
+    }
+
+    #[test]
+    fn test_compute_effective_role_cap_higher_than_user() {
+        let cap = Some("admin".into());
+        assert_eq!(compute_effective_role("viewer", &cap), "viewer");
+        assert_eq!(compute_effective_role("operator", &cap), "operator");
+    }
+
+    #[test]
+    fn test_compute_effective_role_same_level() {
+        let cap = Some("operator".into());
+        assert_eq!(compute_effective_role("operator", &cap), "operator");
+    }
+
+    #[test]
+    fn test_client_ip_no_proxies() {
+        let headers = HeaderMap::new();
+        let ip = client_ip(&headers, "10.0.0.1".parse().unwrap(), &[]);
+        assert_eq!(ip.to_string(), "10.0.0.1");
+    }
+
+    #[test]
+    fn test_client_ip_xff_trusted_proxy() {
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", "203.0.113.50, 10.0.0.1".parse().unwrap());
+        let proxies = vec!["10.0.0.0/8".into()];
+        let ip = client_ip(&headers, "10.0.0.1".parse().unwrap(), &proxies);
+        assert_eq!(ip.to_string(), "203.0.113.50");
+    }
+
+    #[test]
+    fn test_client_ip_xff_untrusted_proxy() {
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", "203.0.113.50".parse().unwrap());
+        let proxies = vec!["10.0.0.0/8".into()];
+        // Socket is NOT in trusted range
+        let ip = client_ip(&headers, "192.168.1.1".parse().unwrap(), &proxies);
+        assert_eq!(ip.to_string(), "192.168.1.1");
+    }
+
+    #[test]
+    fn test_client_ip_xff_invalid_ip() {
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", "not-an-ip".parse().unwrap());
+        let proxies = vec!["10.0.0.0/8".into()];
+        let ip = client_ip(&headers, "10.0.0.1".parse().unwrap(), &proxies);
+        // Falls back to socket addr when XFF can't be parsed
+        assert_eq!(ip.to_string(), "10.0.0.1");
+    }
+
+    #[test]
+    fn test_has_role() {
+        let admin = AuthIdentity::ApiKey("admin".into());
+        assert!(admin.has_role("viewer"));
+        assert!(admin.has_role("admin"));
+
+        let viewer = AuthIdentity::User {
+            email: "test@test.com".into(),
+            role: "viewer".into(),
+            groups: vec![],
+        };
+        assert!(viewer.has_role("viewer"));
+        assert!(!viewer.has_role("operator"));
+        assert!(!viewer.has_role("admin"));
+    }
+}
diff --git a/src/browser.rs b/src/browser.rs
index 055c5ce..a2e626e 100644
--- a/src/browser.rs
+++ b/src/browser.rs
@@ -747,3 +747,113 @@ impl std::fmt::Display for BrowserError {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_encrypt_chromium_password_v10_prefix() {
+        let blob = encrypt_chromium_password("secret").unwrap();
+        assert_eq!(&blob[..3], b"v10");
+    }
+
+    #[test]
+    fn test_encrypt_chromium_password_deterministic() {
+        let a = encrypt_chromium_password("test123").unwrap();
+        let b = encrypt_chromium_password("test123").unwrap();
+        assert_eq!(a, b);
+    }
+
+    #[test]
+    fn test_encrypt_chromium_password_different_inputs() {
+        let a = encrypt_chromium_password("password1").unwrap();
+        let b = encrypt_chromium_password("password2").unwrap();
+        assert_ne!(a, b);
+    }
+
+    #[test]
+    fn test_encrypt_chromium_password_block_aligned() {
+        // AES-128-CBC with PKCS7: output is always multiple of 16 bytes
+        let blob = encrypt_chromium_password("short").unwrap();
+        let ciphertext_len = blob.len() - 3; // minus "v10" prefix
+        assert_eq!(ciphertext_len % 16, 0);
+    }
+
+    #[test]
+    fn test_encrypt_chromium_password_empty() {
+        let blob = encrypt_chromium_password("").unwrap();
+        assert_eq!(&blob[..3], b"v10");
+        // Empty plaintext + PKCS7 padding = one full block
+        assert_eq!(blob.len(), 3 + 16);
+    }
+
+    #[test]
+    fn test_populate_login_data_creates_db() {
+        let dir = std::env::temp_dir().join("rustguac-test-login-data");
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+
+        let creds = vec![(
+            "https://example.com".into(),
+            "alice".into(),
+            "secret".into(),
+        )];
+        populate_login_data(&dir, &creds).unwrap();
+
+        let db_path = dir.join("Default/Login Data");
+        assert!(db_path.exists(), "Login Data SQLite should be created");
+
+        // Verify the database is valid SQLite and has data
+        let conn = rusqlite::Connection::open(&db_path).unwrap();
+        let count: i64 = conn
+            .query_row("SELECT COUNT(*) FROM logins", [], |r| r.get(0))
+            .unwrap();
+        assert_eq!(count, 1);
+
+        let origin: String = conn
+            .query_row("SELECT origin_url FROM logins", [], |r| r.get(0))
+            .unwrap();
+        assert_eq!(origin, "https://example.com/");
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn test_populate_login_data_multiple_creds() {
+        let dir = std::env::temp_dir().join("rustguac-test-login-data-multi");
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+
+        let creds = vec![
+            ("https://app.com".into(), "user1".into(), "pass1".into()),
+            ("https://idp.com".into(), "user2".into(), "pass2".into()),
+        ];
+        populate_login_data(&dir, &creds).unwrap();
+
+        let db_path = dir.join("Default/Login Data");
+        let conn = rusqlite::Connection::open(&db_path).unwrap();
+        let count: i64 = conn
+            .query_row("SELECT COUNT(*) FROM logins", [], |r| r.get(0))
+            .unwrap();
+        assert_eq!(count, 2);
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn test_range_allocator() {
+        let alloc = RangeAllocator::new(100, 102);
+        let a = alloc.allocate().unwrap();
+        let b = alloc.allocate().unwrap();
+        let c = alloc.allocate().unwrap();
+        assert_ne!(a, b);
+        assert_ne!(b, c);
+        // Pool exhausted
+        assert!(alloc.allocate().is_none());
+        // Release one and re-allocate
+        alloc.release(b);
+        let d = alloc.allocate().unwrap();
+        assert_eq!(d, b);
+    }
+}
diff --git a/src/config.rs b/src/config.rs
index f3a3231..ca539d1 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -51,6 +51,13 @@ pub struct VaultConfig {
     /// Only use this for development with self-signed certificates.
     #[serde(default)]
     pub tls_skip_verify: bool,
+    /// Path to a custom CA certificate (PEM) for verifying the Vault server.
+    /// Use this when Vault/OpenBao uses a private or self-signed CA.
+    pub ca_cert: Option<String>,
+    /// Path to a client certificate (PEM) for mTLS authentication to Vault.
+    pub client_cert: Option<String>,
+    /// Path to the client private key (PEM) for mTLS authentication to Vault.
+    pub client_key: Option<String>,
 }
 
 #[derive(Debug, Deserialize, Clone)]
@@ -883,3 +890,87 @@ impl Config {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_builtin_presets_exist() {
+        let presets = builtin_presets();
+        assert!(presets.len() >= 6, "expected at least 6 presets");
+        let names: Vec<&str> = presets.iter().map(|(n, _)| *n).collect();
+        assert!(names.contains(&"dark"));
+        assert!(names.contains(&"light"));
+        assert!(names.contains(&"high-contrast"));
+        assert!(names.contains(&"terminal"));
+        assert!(names.contains(&"nord"));
+        assert!(names.contains(&"corporate"));
+    }
+
+    #[test]
+    fn test_builtin_presets_no_empty_colors() {
+        for (name, colors) in builtin_presets() {
+            assert!(!colors.primary.is_empty(), "{} has empty primary", name);
+            assert!(!colors.bg.is_empty(), "{} has empty bg", name);
+            assert!(!colors.text.is_empty(), "{} has empty text", name);
+        }
+    }
+
+    #[test]
+    fn test_theme_resolve_default_preset() {
+        let cfg: ThemeConfig = toml::from_str("").unwrap();
+        let (name, colors) = cfg.resolve();
+        assert_eq!(name, "dark");
+        assert!(!colors.primary.is_empty());
+    }
+
+    #[test]
+    fn test_theme_resolve_named_preset() {
+        let cfg: ThemeConfig = toml::from_str(r#"preset = "light""#).unwrap();
+        let (name, _) = cfg.resolve();
+        assert_eq!(name, "light");
+    }
+
+    #[test]
+    fn test_theme_resolve_override() {
+        let cfg: ThemeConfig =
+            toml::from_str("preset = \"dark\"\nprimary_color = \"#ff0000\"").unwrap();
+        let (_, colors) = cfg.resolve();
+        assert_eq!(colors.primary, "#ff0000");
+    }
+
+    #[test]
+    fn test_theme_resolve_unknown_preset_falls_back() {
+        let cfg: ThemeConfig = toml::from_str(r#"preset = "nonexistent""#).unwrap();
+        let (name, colors) = cfg.resolve();
+        assert_eq!(name, "nonexistent");
+        // Falls back to first preset (dark)
+        let dark = &builtin_presets()[0].1;
+        assert_eq!(colors.primary, dark.primary);
+    }
+
+    #[test]
+    fn test_config_defaults() {
+        assert_eq!(default_listen_addr(), "127.0.0.1:8089");
+        assert_eq!(default_guacd_addr(), "127.0.0.1:4822");
+        assert_eq!(default_display_range_start(), 100);
+        assert_eq!(default_display_range_end(), 199);
+        assert_eq!(default_cdp_port_range_start(), 9200);
+        assert_eq!(default_cdp_port_range_end(), 9299);
+    }
+
+    #[test]
+    fn test_vault_config_deserialize_minimal() {
+        let toml_str = r#"
+            addr = "https://vault:8200"
+            role_id = "test"
+        "#;
+        let config: VaultConfig = toml::from_str(toml_str).unwrap();
+        assert_eq!(config.addr, "https://vault:8200");
+        assert_eq!(config.mount, "secret");
+        assert_eq!(config.base_path, "rustguac");
+        assert!(!config.tls_skip_verify);
+        assert!(config.ca_cert.is_none());
+    }
+}
diff --git a/src/db.rs b/src/db.rs
index 31ad22c..b77bb83 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -919,3 +919,83 @@ pub fn resolve_role_from_groups(db: &Db, groups: &[String]) -> rusqlite::Result<
 
     Ok(best_role)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_hash_key_sha256() {
+        let hash = hash_key("test-api-key");
+        assert_eq!(hash.len(), 64); // SHA-256 = 64 hex chars
+                                    // Deterministic
+        assert_eq!(hash, hash_key("test-api-key"));
+    }
+
+    #[test]
+    fn test_hash_key_different_inputs() {
+        assert_ne!(hash_key("key-a"), hash_key("key-b"));
+    }
+
+    #[test]
+    fn test_generate_key_format() {
+        let key = generate_key();
+        assert_eq!(key.len(), 64); // 32 bytes = 64 hex chars
+        assert!(key.chars().all(|c| c.is_ascii_hexdigit()));
+    }
+
+    #[test]
+    fn test_generate_key_unique() {
+        let a = generate_key();
+        let b = generate_key();
+        assert_ne!(a, b);
+    }
+
+    #[test]
+    fn test_user_groups_vec() {
+        let user = User {
+            id: 1,
+            oidc_subject: None,
+            created_at: "2025-01-01".into(),
+            last_login_at: None,
+            email: "test@test.com".into(),
+            name: "test".into(),
+            role: "viewer".into(),
+            disabled: false,
+            oidc_groups: "admins,developers,ops".into(),
+        };
+        assert_eq!(user.groups_vec(), vec!["admins", "developers", "ops"]);
+    }
+
+    #[test]
+    fn test_user_groups_vec_empty() {
+        let user = User {
+            id: 1,
+            oidc_subject: None,
+            created_at: "2025-01-01".into(),
+            last_login_at: None,
+            email: "test@test.com".into(),
+            name: "test".into(),
+            role: "viewer".into(),
+            disabled: false,
+            oidc_groups: String::new(),
+        };
+        assert!(user.groups_vec().is_empty());
+    }
+
+    #[test]
+    fn test_user_groups_vec_single() {
+        let user = User {
+            id: 1,
+            oidc_subject: None,
+            created_at: "2025-01-01".into(),
+            last_login_at: None,
+            email: "test@test.com".into(),
+            name: "test".into(),
+            role: "viewer".into(),
+            disabled: false,
+            oidc_groups: "solo-group".into(),
+        };
+        assert_eq!(user.groups_vec(), vec!["solo-group"]);
+    }
+}
diff --git a/src/import.rs b/src/import.rs
index fd4662c..88a4203 100644
--- a/src/import.rs
+++ b/src/import.rs
@@ -128,14 +128,20 @@ pub async fn cmd_import_guacamole(
     );
 
     if dry_run {
-        println!("\n[DRY RUN] Would import to folder \"{}\" (scope: {}):\n", folder, scope);
+        println!(
+            "\n[DRY RUN] Would import to folder \"{}\" (scope: {}):\n",
+            folder, scope
+        );
         for (name, entry) in &entries {
             println!(
                 "  {} ({}) → {}:{}",
                 name,
                 entry.session_type,
                 entry.hostname.as_deref().unwrap_or("?"),
-                entry.port.map(|p| p.to_string()).unwrap_or_else(|| "?".into()),
+                entry
+                    .port
+                    .map(|p| p.to_string())
+                    .unwrap_or_else(|| "?".into()),
             );
             if let Some(ref dn) = entry.display_name {
                 if dn != name {
@@ -177,7 +183,10 @@ pub async fn cmd_import_guacamole(
         allowed_groups: vec![],
         description: "Imported from Guacamole".to_string(),
     };
-    if let Err(e) = client.put_folder_config(scope, folder, &folder_config).await {
+    if let Err(e) = client
+        .put_folder_config(scope, folder, &folder_config)
+        .await
+    {
         eprintln!("Error creating folder \"{}\": {}", folder, e);
         std::process::exit(1);
     }
@@ -268,7 +277,10 @@ fn parse_parameters(sql: &str) -> HashMap<i64, Vec<(String, String)>> {
                 };
                 let param_name = unescape_sql(&vals[1]);
                 let param_value = unescape_sql(&vals[2]);
-                results.entry(id).or_default().push((param_name, param_value));
+                results
+                    .entry(id)
+                    .or_default()
+                    .push((param_name, param_value));
             }
         }
     }
@@ -569,7 +581,8 @@ mod tests {
 
     #[test]
     fn test_extract_tuples() {
-        let line = "INSERT INTO `guacamole_connection` VALUES (1,'web',NULL,'ssh'),(2,'db',1,'rdp');";
+        let line =
+            "INSERT INTO `guacamole_connection` VALUES (1,'web',NULL,'ssh'),(2,'db',1,'rdp');";
         let tuples = extract_tuples(line);
         assert_eq!(tuples.len(), 2);
         assert_eq!(tuples[0], "1,'web',NULL,'ssh'");
@@ -675,9 +688,21 @@ mod tests {
     #[test]
     fn test_group_path_nesting() {
         let groups = vec![
-            Group { id: 1, parent_id: None, name: "Production".into() },
-            Group { id: 2, parent_id: Some(1), name: "DMZ".into() },
-            Group { id: 3, parent_id: Some(2), name: "Web".into() },
+            Group {
+                id: 1,
+                parent_id: None,
+                name: "Production".into(),
+            },
+            Group {
+                id: 2,
+                parent_id: Some(1),
+                name: "DMZ".into(),
+            },
+            Group {
+                id: 3,
+                parent_id: Some(2),
+                name: "Web".into(),
+            },
         ];
         let paths = build_group_paths(&groups);
         assert_eq!(paths[&1], "Production");
diff --git a/src/main.rs b/src/main.rs
index 116f9d6..9b9cd0a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,6 +5,7 @@ mod config;
 mod db;
 mod drive;
 mod guacd;
+mod import;
 mod oidc;
 mod protocol;
 mod recording;
diff --git a/src/session.rs b/src/session.rs
index 012c512..5941f90 100644
--- a/src/session.rs
+++ b/src/session.rs
@@ -1203,6 +1203,115 @@ pub enum SessionError {
     BrowserSpawn(String),
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_check_allowed_network_ipv4_match() {
+        assert!(check_allowed_network("127.0.0.1", 22, &["127.0.0.0/8".into()]).is_ok());
+        assert!(check_allowed_network("10.1.2.3", 80, &["10.0.0.0/8".into()]).is_ok());
+    }
+
+    #[test]
+    fn test_check_allowed_network_ipv4_denied() {
+        let err = check_allowed_network("8.8.8.8", 22, &["127.0.0.0/8".into()]);
+        assert!(err.is_err());
+    }
+
+    #[test]
+    fn test_check_allowed_network_empty_allowlist() {
+        let err = check_allowed_network("127.0.0.1", 22, &[]);
+        assert!(err.is_err());
+        let msg = format!("{}", err.unwrap_err());
+        assert!(msg.contains("no valid CIDR"), "got: {}", msg);
+    }
+
+    #[test]
+    fn test_check_allowed_network_multiple_cidrs() {
+        let cidrs = vec!["10.0.0.0/8".into(), "192.168.0.0/16".into()];
+        assert!(check_allowed_network("10.1.1.1", 22, &cidrs).is_ok());
+        assert!(check_allowed_network("192.168.1.1", 22, &cidrs).is_ok());
+        assert!(check_allowed_network("172.16.0.1", 22, &cidrs).is_err());
+    }
+
+    #[test]
+    fn test_check_allowed_network_localhost_resolves() {
+        // "localhost" should resolve to 127.0.0.1 or ::1
+        let cidrs = vec!["127.0.0.0/8".into(), "::1/128".into()];
+        assert!(check_allowed_network("localhost", 80, &cidrs).is_ok());
+    }
+
+    #[test]
+    fn test_parse_autofill_none() {
+        assert!(parse_autofill_credentials(None, None, None).is_none());
+    }
+
+    #[test]
+    fn test_parse_autofill_empty_string() {
+        assert!(parse_autofill_credentials(Some(""), None, None).is_none());
+    }
+
+    #[test]
+    fn test_parse_autofill_invalid_json() {
+        assert!(parse_autofill_credentials(Some("not json"), None, None).is_none());
+    }
+
+    #[test]
+    fn test_parse_autofill_empty_array() {
+        assert!(parse_autofill_credentials(Some("[]"), None, None).is_none());
+    }
+
+    #[test]
+    fn test_parse_autofill_basic() {
+        let json = r#"[{"url":"https://example.com","username":"alice","password":"secret"}]"#;
+        let creds = parse_autofill_credentials(Some(json), None, None).unwrap();
+        assert_eq!(creds.len(), 1);
+        assert_eq!(creds[0].0, "https://example.com");
+        assert_eq!(creds[0].1, "alice");
+        assert_eq!(creds[0].2, "secret");
+    }
+
+    #[test]
+    fn test_parse_autofill_placeholder_substitution() {
+        let json = r#"[{"url":"https://ex.com","username":"$USERNAME","password":"$PASSWORD"}]"#;
+        let creds = parse_autofill_credentials(Some(json), Some("bob"), Some("pass123")).unwrap();
+        assert_eq!(creds[0].1, "bob");
+        assert_eq!(creds[0].2, "pass123");
+    }
+
+    #[test]
+    fn test_parse_autofill_placeholder_no_credentials() {
+        // Placeholders with no username/password should substitute empty strings
+        let json = r#"[{"url":"https://ex.com","username":"$USERNAME","password":"$PASSWORD"}]"#;
+        let creds = parse_autofill_credentials(Some(json), None, None).unwrap();
+        assert_eq!(creds[0].1, "");
+        assert_eq!(creds[0].2, "");
+    }
+
+    #[test]
+    fn test_parse_autofill_multiple_entries() {
+        let json = r#"[
+            {"url":"https://app.com","username":"$USERNAME","password":"$PASSWORD"},
+            {"url":"https://idp.com","username":"$USERNAME","password":"$PASSWORD"}
+        ]"#;
+        let creds = parse_autofill_credentials(Some(json), Some("alice"), Some("secret")).unwrap();
+        assert_eq!(creds.len(), 2);
+        assert_eq!(creds[0].0, "https://app.com");
+        assert_eq!(creds[1].0, "https://idp.com");
+    }
+
+    #[test]
+    fn test_parse_autofill_missing_fields_skipped() {
+        // Entries missing required fields are silently skipped
+        let json =
+            r#"[{"url":"https://ex.com"},{"url":"https://ok.com","username":"a","password":"b"}]"#;
+        let creds = parse_autofill_credentials(Some(json), None, None).unwrap();
+        assert_eq!(creds.len(), 1);
+        assert_eq!(creds[0].0, "https://ok.com");
+    }
+}
+
 impl std::fmt::Display for SessionError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
diff --git a/src/vault.rs b/src/vault.rs
index 23502ba..02ea47d 100644
--- a/src/vault.rs
+++ b/src/vault.rs
@@ -297,10 +297,7 @@ impl VaultClient {
                 "Vault TLS certificate verification is DISABLED (tls_skip_verify = true)"
             );
         }
-        let http = reqwest::Client::builder()
-            .danger_accept_invalid_certs(config.tls_skip_verify)
-            .build()
-            .map_err(|e| VaultError::Auth(format!("failed to create HTTP client: {}", e)))?;
+        let http = build_vault_http_client(config)?;
 
         let client = Self {
             http,
@@ -754,6 +751,50 @@ impl VaultClient {
     }
 }
 
+/// Build a reqwest HTTP client from a VaultConfig (extracted for testability).
+fn build_vault_http_client(config: &VaultConfig) -> Result<reqwest::Client, VaultError> {
+    let mut builder =
+        reqwest::Client::builder().danger_accept_invalid_certs(config.tls_skip_verify);
+
+    // Custom CA certificate for private/self-signed CAs
+    if let Some(ref ca_path) = config.ca_cert {
+        let pem = std::fs::read(ca_path)
+            .map_err(|e| VaultError::Auth(format!("failed to read CA cert {}: {}", ca_path, e)))?;
+        let cert = reqwest::Certificate::from_pem(&pem)
+            .map_err(|e| VaultError::Auth(format!("failed to parse CA cert {}: {}", ca_path, e)))?;
+        builder = builder.add_root_certificate(cert);
+        tracing::info!("Vault TLS: using custom CA certificate from {}", ca_path);
+    }
+
+    // Client certificate for mTLS
+    if let Some(ref cert_path) = config.client_cert {
+        let key_path = config.client_key.as_deref().ok_or_else(|| {
+            VaultError::Auth(
+                "client_cert is set but client_key is missing in [vault] config".into(),
+            )
+        })?;
+        let cert_pem = std::fs::read(cert_path).map_err(|e| {
+            VaultError::Auth(format!("failed to read client cert {}: {}", cert_path, e))
+        })?;
+        let key_pem = std::fs::read(key_path).map_err(|e| {
+            VaultError::Auth(format!("failed to read client key {}: {}", key_path, e))
+        })?;
+        let mut identity_pem = cert_pem;
+        identity_pem.extend_from_slice(&key_pem);
+        let identity = reqwest::Identity::from_pem(&identity_pem)
+            .map_err(|e| VaultError::Auth(format!("failed to parse client identity: {}", e)))?;
+        builder = builder.identity(identity);
+        tracing::info!(
+            "Vault TLS: using client certificate from {} (mTLS)",
+            cert_path
+        );
+    }
+
+    builder
+        .build()
+        .map_err(|e| VaultError::Auth(format!("failed to create HTTP client: {}", e)))
+}
+
 /// Validate that a folder or entry name is safe (alphanumeric, hyphens, underscores, dots — no path traversal).
 fn validate_name(name: &str) -> Result<(), VaultError> {
     if name.is_empty() || name.len() > 64 {
@@ -777,3 +818,206 @@ fn validate_name(name: &str) -> Result<(), VaultError> {
     }
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn base_config() -> VaultConfig {
+        VaultConfig {
+            addr: "https://vault.example.com:8200".into(),
+            mount: "secret".into(),
+            base_path: "rustguac".into(),
+            role_id: "test-role-id".into(),
+            namespace: None,
+            instance_name: None,
+            tls_skip_verify: false,
+            ca_cert: None,
+            client_cert: None,
+            client_key: None,
+        }
+    }
+
+    #[test]
+    fn test_build_client_defaults() {
+        let config = base_config();
+        let client = build_vault_http_client(&config);
+        assert!(client.is_ok());
+    }
+
+    #[test]
+    fn test_build_client_tls_skip_verify() {
+        let mut config = base_config();
+        config.tls_skip_verify = true;
+        let client = build_vault_http_client(&config);
+        assert!(client.is_ok());
+    }
+
+    #[test]
+    fn test_build_client_ca_cert_missing_file() {
+        let mut config = base_config();
+        config.ca_cert = Some("/nonexistent/ca.pem".into());
+        let err = build_vault_http_client(&config).unwrap_err();
+        let msg = err.to_string();
+        assert!(msg.contains("failed to read CA cert"), "got: {}", msg);
+        assert!(msg.contains("/nonexistent/ca.pem"), "got: {}", msg);
+    }
+
+    #[test]
+    fn test_build_client_ca_cert_invalid_pem() {
+        // reqwest::Certificate::from_pem rejects PEM with valid headers but
+        // garbage DER content.
+        let dir = std::env::temp_dir().join("rustguac-test-vault-tls");
+        let _ = std::fs::create_dir_all(&dir);
+        let ca_path = dir.join("bad-ca.pem");
+        let bad_pem =
+            "-----BEGIN CERTIFICATE-----\nDEFINITELYnotvalid!!!\n-----END CERTIFICATE-----\n";
+        std::fs::write(&ca_path, bad_pem.as_bytes()).unwrap();
+
+        let mut config = base_config();
+        config.ca_cert = Some(ca_path.to_str().unwrap().into());
+        let result = build_vault_http_client(&config);
+        assert!(result.is_err(), "expected error for invalid PEM");
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn test_build_client_client_cert_without_key() {
+        let dir = std::env::temp_dir().join("rustguac-test-vault-tls-nokey");
+        let _ = std::fs::create_dir_all(&dir);
+        let cert_path = dir.join("client.pem");
+        std::fs::write(&cert_path, b"placeholder").unwrap();
+
+        let mut config = base_config();
+        config.client_cert = Some(cert_path.to_str().unwrap().into());
+        // client_key intentionally None
+        let err = build_vault_http_client(&config).unwrap_err();
+        let msg = err.to_string();
+        assert!(msg.contains("client_key is missing"), "got: {}", msg);
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn test_build_client_client_cert_missing_file() {
+        let mut config = base_config();
+        config.client_cert = Some("/nonexistent/client.pem".into());
+        config.client_key = Some("/nonexistent/client-key.pem".into());
+        let err = build_vault_http_client(&config).unwrap_err();
+        let msg = err.to_string();
+        assert!(msg.contains("failed to read client cert"), "got: {}", msg);
+    }
+
+    #[test]
+    fn test_build_client_client_key_missing_file() {
+        let dir = std::env::temp_dir().join("rustguac-test-vault-tls-keyfile");
+        let _ = std::fs::create_dir_all(&dir);
+        let cert_path = dir.join("client.pem");
+        std::fs::write(&cert_path, b"placeholder cert").unwrap();
+
+        let mut config = base_config();
+        config.client_cert = Some(cert_path.to_str().unwrap().into());
+        config.client_key = Some("/nonexistent/client-key.pem".into());
+        let err = build_vault_http_client(&config).unwrap_err();
+        let msg = err.to_string();
+        assert!(msg.contains("failed to read client key"), "got: {}", msg);
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn test_build_client_valid_ca_cert() {
+        let dir = std::env::temp_dir().join("rustguac-test-vault-tls-valid");
+        let _ = std::fs::create_dir_all(&dir);
+        let ca_path = dir.join("ca.pem");
+
+        // Generate a real self-signed cert via openssl
+        let output = std::process::Command::new("openssl")
+            .args([
+                "req",
+                "-x509",
+                "-newkey",
+                "ec",
+                "-pkeyopt",
+                "ec_paramgen_curve:prime256v1",
+                "-keyout",
+                "/dev/null",
+                "-out",
+                ca_path.to_str().unwrap(),
+                "-days",
+                "1",
+                "-nodes",
+                "-subj",
+                "/CN=Test CA",
+            ])
+            .output()
+            .expect("openssl must be available for this test");
+        assert!(output.status.success(), "openssl failed: {:?}", output);
+
+        let mut config = base_config();
+        config.ca_cert = Some(ca_path.to_str().unwrap().into());
+        let result = build_vault_http_client(&config);
+        assert!(result.is_ok(), "expected Ok, got: {:?}", result.err());
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn test_config_deserialize_tls_fields() {
+        let toml_str = r#"
+            addr = "https://vault.example.com:8200"
+            role_id = "test-role"
+            ca_cert = "/opt/rustguac/certs/ca.pem"
+            client_cert = "/opt/rustguac/certs/client.pem"
+            client_key = "/opt/rustguac/certs/client-key.pem"
+            tls_skip_verify = true
+        "#;
+        let config: VaultConfig = toml::from_str(toml_str).unwrap();
+        assert_eq!(
+            config.ca_cert.as_deref(),
+            Some("/opt/rustguac/certs/ca.pem")
+        );
+        assert_eq!(
+            config.client_cert.as_deref(),
+            Some("/opt/rustguac/certs/client.pem")
+        );
+        assert_eq!(
+            config.client_key.as_deref(),
+            Some("/opt/rustguac/certs/client-key.pem")
+        );
+        assert!(config.tls_skip_verify);
+    }
+
+    #[test]
+    fn test_config_deserialize_no_tls_fields() {
+        let toml_str = r#"
+            addr = "https://vault.example.com:8200"
+            role_id = "test-role"
+        "#;
+        let config: VaultConfig = toml::from_str(toml_str).unwrap();
+        assert!(config.ca_cert.is_none());
+        assert!(config.client_cert.is_none());
+        assert!(config.client_key.is_none());
+        assert!(!config.tls_skip_verify);
+    }
+
+    #[test]
+    fn test_validate_name_ok() {
+        assert!(validate_name("my-entry.v2").is_ok());
+        assert!(validate_name("a").is_ok());
+    }
+
+    #[test]
+    fn test_validate_name_rejects_traversal() {
+        assert!(validate_name("../etc").is_err());
+        assert!(validate_name("foo/bar").is_err());
+        assert!(validate_name(".config").is_err());
+    }
+
+    #[test]
+    fn test_validate_name_rejects_empty_and_long() {
+        assert!(validate_name("").is_err());
+        assert!(validate_name(&"a".repeat(65)).is_err());
+    }
+}