nip55: init

- Add `AndroidSigner`
- Add `AndroidSigner::is_external_signer_installed`

Closes #938

Signed-off-by: Yuki Kishimoto <yukikishimoto@protonmail.com>

Author: yukibtc

Cargo.lock

@@ -49,6 +49,7 @@ nostr-ndb = { version = "0.42", path = "./database/nostr-ndb", default-features
 nostr-relay-builder = { version = "0.42", path = "./crates/nostr-relay-builder", default-features = false }
 nostr-relay-pool = { version = "0.42", path = "./crates/nostr-relay-pool", default-features = false }
 nostr-sdk = { version = "0.42", path = "./crates/nostr-sdk", default-features = false }
+once_cell = "1.21"
 reqwest = { version = "0.12", default-features = false }
 serde = { version = "1.0", default-features = false }
 serde_json = { version = "1.0", default-features = false }

Cargo.toml

@@ -37,6 +37,7 @@ buildargs=(
     "-p nostr --no-default-features --features alloc"             # Only alloc feature
     "-p nostr --no-default-features --features alloc,all-nips"    # alloc + all-nips
     "-p nip07 --target wasm32-unknown-unknown"
+    "-p nip55"
     "-p nostr-blossom"
     "-p nostr-http-file-storage"
     "-p nostr-database"

contrib/scripts/check-crates.sh

@@ -5,6 +5,7 @@ set -euo pipefail
 args=(
     "-p nostr"
     "-p nip07"
+    "-p nip55"
     "-p nostr-database"
     "-p nostr-lmdb"
     "-p nostr-mls-storage"

contrib/scripts/release.sh

@@ -0,0 +1,18 @@
+[package]
+name = "nip55"
+version = "0.42.0"
+edition = "2021"
+description = "Nostr Android signer implementation (NIP-55)."
+authors.workspace = true
+homepage.workspace = true
+repository.workspace = true
+license.workspace = true
+readme = "README.md"
+rust-version.workspace = true
+keywords = ["nostr", "nip55", "android", "signer"]
+
+[dependencies]
+jni = "0.21"
+jvm-getter = "0.1"
+nostr = { workspace = true, features = ["std"] }
+once_cell = "1.21"

crates/nip55/Cargo.toml

@@ -0,0 +1,17 @@
+# Android signer (NIP-55)
+
+## Description
+
+Nostr Android signer implementation ([NIP-55](https://github.com/nostr-protocol/nips/blob/master/55.md)).
+
+## State
+
+**This library is in an ALPHA state**, things that are implemented generally work but the API will change in breaking ways.
+
+## Donations
+
+`rust-nostr` is free and open-source. This means we do not earn any revenue by selling it. Instead, we rely on your financial support. If you actively use any of the `rust-nostr` libs/software/services, then please [donate](https://rust-nostr.org/donate).
+
+## License
+
+This project is distributed under the MIT software license - see the [LICENSE](../../LICENSE) file for details

crates/nip55/README.md

@@ -0,0 +1,45 @@
+// Copyright (c) 2022-2023 Yuki Kishimoto
+// Copyright (c) 2023-2025 Rust Nostr Developers
+// Distributed under the MIT software license
+
+//! Android Signer error
+
+use std::fmt;
+
+use jni::errors::Error as JniError;
+use nostr::event;
+
+/// Android Signer error
+#[derive(Debug)]
+pub enum Error {
+    /// JNI error
+    Jni(JniError),
+    /// Nostr event error
+    Event(event::Error),
+    /// Can't find the JVM
+    JVMNotFound,
+}
+
+impl std::error::Error for Error {}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Jni(e) => write!(f, "{e}"),
+            Self::Event(e) => write!(f, "{e}"),
+            Self::JVMNotFound => write!(f, "JVM not found"),
+        }
+    }
+}
+
+impl From<JniError> for Error {
+    fn from(e: JniError) -> Self {
+        Self::Jni(e)
+    }
+}
+
+impl From<event::Error> for Error {
+    fn from(e: event::Error) -> Self {
+        Self::Event(e)
+    }
+}