diff --git a/Cargo.toml b/Cargo.toml
index 27b7505..aa7bc62 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,5 +4,6 @@ resolver = "2"
 members = [
     "rust/joinstr",
     "rust/simple_nostr_client",
-    "rust/simple_electrum_client", 
+    "rust/simple_electrum_client",
+    "rust/joinstr_wallet",
 ]
diff --git a/rust/joinstr/src/lib.rs b/rust/joinstr/src/lib.rs
index 7f0dd83..33e18bc 100644
--- a/rust/joinstr/src/lib.rs
+++ b/rust/joinstr/src/lib.rs
@@ -9,6 +9,8 @@ pub mod utils;
 pub use bip39;
 pub use log;
 pub use miniscript;
+pub use serde;
+pub use serde_json;
 
 #[cfg(feature = "async")]
 pub use nostr_sdk;
@@ -19,7 +21,7 @@ use std::{
     ptr::null,
 };
 
-fn serialize_to_cstring<T>(value: T) -> Result<CString, Error>
+pub fn serialize_to_cstring<T>(value: T) -> Result<CString, Error>
 where
     T: Serialize,
 {
diff --git a/rust/joinstr_wallet/Cargo.toml b/rust/joinstr_wallet/Cargo.toml
new file mode 100644
index 0000000..51afaa6
--- /dev/null
+++ b/rust/joinstr_wallet/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "joinstr_wallet"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["rlib", "cdylib", "staticlib"]
+
+[dependencies]
+dirs = "6.0.0"
+joinstr = { path = "../joinstr" }
+libc = "0.2.170"
+serde = { version = "1.0.218", features = ["derive"] }
+url = "2.5.4"
+
+
diff --git a/rust/joinstr_wallet/src/lib.rs b/rust/joinstr_wallet/src/lib.rs
new file mode 100644
index 0000000..a1846d6
--- /dev/null
+++ b/rust/joinstr_wallet/src/lib.rs
@@ -0,0 +1,2 @@
+mod settings;
+pub use settings::*;
diff --git a/rust/joinstr_wallet/src/settings.rs b/rust/joinstr_wallet/src/settings.rs
new file mode 100644
index 0000000..c42e4f9
--- /dev/null
+++ b/rust/joinstr_wallet/src/settings.rs
@@ -0,0 +1,223 @@
+use std::{
+    ffi::{c_char, c_int, CStr, CString},
+    fs::File,
+    io::Read,
+    path::{Path, PathBuf},
+    ptr,
+    str::FromStr,
+};
+
+use libc::malloc;
+
+use joinstr::{bip39::Mnemonic, serde_json};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+type MutStrPtr = *mut *mut c_char;
+type ConstStr = *const c_char;
+
+fn datadir() -> PathBuf {
+    #[cfg(target_os = "linux")]
+    let mut dir = {
+        let mut dir = dirs::home_dir().unwrap();
+        dir.push(".joinstr");
+        dir
+    };
+
+    #[cfg(not(target_os = "linux"))]
+    let mut dir = {
+        let mut dir = dirs::config_dir().unwrap();
+        dir.push("Joinstr");
+        dir
+    };
+
+    maybe_create_dir(&dir);
+
+    dir.push("joinstr.conf");
+
+    dir
+}
+
+fn maybe_create_dir(dir: &PathBuf) {
+    if !dir.exists() {
+        #[cfg(unix)]
+        {
+            use std::fs::DirBuilder;
+            use std::os::unix::fs::DirBuilderExt;
+
+            let mut builder = DirBuilder::new();
+            builder.mode(0o700).recursive(true).create(dir).unwrap();
+        }
+
+        #[cfg(not(unix))]
+        std::fs::create_dir_all(dir).unwrap();
+    }
+}
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn is_mnemonic_valid(mnemonic: ConstStr) -> c_int {
+    let cstr = unsafe { CStr::from_ptr(mnemonic) };
+    let mnemonic = match cstr.to_str() {
+        Ok(r) => r,
+        Err(_) => return -1,
+    };
+    match Mnemonic::from_str(mnemonic).is_ok() {
+        true => 0,
+        false => -2,
+    }
+}
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn is_electrum_valid(addr: ConstStr) -> c_int {
+    let cstr = unsafe { CStr::from_ptr(addr) };
+    let electrum = match cstr.to_str() {
+        Ok(r) => r,
+        Err(_) => return -1,
+    };
+    let separators = electrum.chars().filter(|c| *c == ':').count();
+    if separators != 1 {
+        return -2;
+    }
+    let (url, port) = electrum.split_once(':').expect("checked");
+    let port = u16::from_str(port).is_ok();
+    let url = Url::parse(url).is_ok();
+    if !url {
+        -3
+    } else if !port {
+        -4
+    } else {
+        0
+    }
+}
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn is_relay_valid(addr: ConstStr) -> c_int {
+    let cstr = unsafe { CStr::from_ptr(addr) };
+    let url = match cstr.to_str() {
+        Ok(r) => r,
+        Err(_) => return -1,
+    };
+    match Url::parse(url).is_ok() {
+        true => 0,
+        false => -2,
+    }
+}
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn save_settings(
+    mnemonics: ConstStr,
+    electrum: ConstStr,
+    relay: ConstStr,
+) -> c_int {
+    if is_mnemonic_valid(mnemonics) != 0 {
+        return -1;
+    }
+    if is_electrum_valid(electrum) != 0 {
+        return -2;
+    }
+    if is_relay_valid(relay) != 0 {
+        return -3;
+    }
+    let mnemonics = unsafe { CStr::from_ptr(mnemonics) }.to_str();
+    let electrum = unsafe { CStr::from_ptr(electrum) }.to_str();
+    let relay = unsafe { CStr::from_ptr(relay) }.to_str();
+
+    if let (Ok(mnemonics), Ok(electrum), Ok(relay)) = (mnemonics, electrum, relay) {
+        if Settings::new(mnemonics, electrum, relay).to_file(&datadir()) != 0 {
+            -4
+        } else {
+            0
+        }
+    } else {
+        -5
+    }
+}
+
+unsafe fn write_string(src: &str, dst: *mut *mut c_char) -> c_int {
+    let c_str = match CString::new(src) {
+        Ok(r) => r,
+        Err(_) => return -1,
+    };
+    let len = c_str.as_bytes_with_nul().len();
+    let mem = malloc(len) as *mut c_char;
+    if mem.is_null() {
+        return -2;
+    }
+    ptr::copy_nonoverlapping(c_str.as_ptr(), mem, len);
+    *dst = mem;
+    0
+}
+
+#[no_mangle]
+#[allow(clippy::missing_safety_doc)]
+pub unsafe extern "C" fn load_settings(
+    mnemonics: MutStrPtr,
+    electrum: MutStrPtr,
+    relay: MutStrPtr,
+) -> c_int {
+    if mnemonics.is_null() || electrum.is_null() || relay.is_null() {
+        return -1;
+    }
+    let settings = match Settings::from_file(&datadir()) {
+        Some(s) => s,
+        None => return -2,
+    };
+
+    if write_string(&settings.mnemonics, mnemonics) != 0 {
+        return -3;
+    }
+    if write_string(&settings.electrum, electrum) != 0 {
+        return -4;
+    }
+    if write_string(&settings.relay, relay) != 0 {
+        return -5;
+    }
+
+    0
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct Settings {
+    pub mnemonics: String,
+    pub electrum: String,
+    pub relay: String,
+}
+
+impl Settings {
+    pub fn new(mnemonics: &str, electrum: &str, relay: &str) -> Self {
+        Settings {
+            mnemonics: mnemonics.into(),
+            electrum: electrum.into(),
+            relay: relay.into(),
+        }
+    }
+
+    pub fn to_file(&self, path: &Path) -> c_int {
+        let path: &str = &path.to_string_lossy();
+        let file = match File::create(path) {
+            Ok(f) => f,
+            Err(_) => return -1,
+        };
+        if serde_json::to_writer_pretty(file, self).is_ok() {
+            0
+        } else {
+            -2
+        }
+    }
+
+    pub fn from_file(path: &Path) -> Option<Self> {
+        if !path.exists() || !path.is_file() {
+            return None;
+        }
+
+        let mut file = File::open(path).ok()?;
+        let mut settings_str = String::new();
+        let _conf_size = file.read_to_string(&mut settings_str).ok()?;
+        let conf: Self = serde_json::from_str(&settings_str).ok()?;
+        Some(conf)
+    }
+}