Add test: FetchOhttpKeys in non-Tokio context

payjoin-ffi/Cargo.toml

@@ -33,7 +33,7 @@ serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.142"
 thiserror = "2.0.14"
 tokio = { version = "1.47.1", features = ["full"], optional = true }
-uniffi = { version = "0.30.0", features = ["cli"] }
+uniffi = { version = "0.30.0", features = ["cli", "tokio"] }
 uniffi-bindgen-cs = { git = "https://github.com/chavic/uniffi-bindgen-cs.git", rev = "878a3d269eacce64beadcd336ade0b7c8da09824", optional = true }
 uniffi-dart = { git = "https://github.com/Uniffi-Dart/uniffi-dart.git", rev = "f830323", optional = true }
 url = "2.5.4"

payjoin-ffi/csharp/IntegrationTests.cs

@@ -323,6 +323,32 @@ public ValueTask DisposeAsync()
             return ValueTask.CompletedTask;
         }
 
+        /// <summary>
+        /// Regression test: <see cref="PayjoinMethods.FetchOhttpKeysWithCert"/> called from a plain .NET async
+        /// context should successfully return OHTTP keys.
+        ///
+        /// Without the fix this test fails with:
+        ///   PanicException: "there is no reactor running, must be called from the context of a Tokio 1.x runtime"
+        /// </summary>
+        [Fact]
+        public async Task FetchOhttpKeys_ShouldWorkFromNonTokioContext()
+        {
+            // Arrange: use TestServices' URLs and certificate so connectivity is guaranteed and
+            // the failure (if any) is purely about missing Tokio runtime, not TLS trust setup.
+            _services!.WaitForServicesReady();
+            var ohttpRelay = _services.OhttpRelayUrl();
+            var directory = _services.DirectoryUrl();
+            var cert = _services.Cert();
+
+            // Act: call the raw UniFFI async binding directly — NOT TestServices.FetchOhttpKeys(),
+            // which uses an internal block_on(RUNTIME) and therefore always has a Tokio context.
+            // PayjoinMethods.FetchOhttpKeysWithCert() has no such safety net.
+            var keys = await PayjoinMethods.FetchOhttpKeysWithCert(ohttpRelay, directory, cert);
+
+            // Assert
+            Assert.NotNull(keys);
+        }
+
         [Fact]
         public void TestFfiValidation()
         {

payjoin-ffi/csharp/README.md

@@ -56,20 +56,20 @@ dotnet test
 
 Generation uses the Cargo-managed C# generator from `payjoin-ffi/Cargo.toml`.
 
-By default, generation builds `payjoin-ffi` with `_test-utils` enabled to keep parity with other language test scripts. Override via `PAYJOIN_FFI_FEATURES`.
+By default, generation builds `payjoin-ffi` with `_test-utils,_manual-tls` so C# integration tests can use local HTTPS services with generated self-signed certificates. Override via `PAYJOIN_FFI_FEATURES`.
 
 ### Unix shells
 
 ```shell
-export PAYJOIN_FFI_FEATURES=_test-utils     # default behavior
+export PAYJOIN_FFI_FEATURES=_test-utils,_manual-tls     # default behavior
 # export PAYJOIN_FFI_FEATURES=""            # build without extra features
 bash ./scripts/generate_bindings.sh
 ```
 
 ### PowerShell
 
 ```powershell
-$env:PAYJOIN_FFI_FEATURES = "_test-utils"   # default behavior
+$env:PAYJOIN_FFI_FEATURES = "_test-utils,_manual-tls"   # default behavior
 # $env:PAYJOIN_FFI_FEATURES = ""            # build without extra features
 powershell -ExecutionPolicy Bypass -File .\scripts\generate_bindings.ps1
 dotnet build

payjoin-ffi/csharp/scripts/generate_bindings.ps1

@@ -40,8 +40,9 @@ Write-Host "Generating payjoin C#..."
 if ($null -ne $env:PAYJOIN_FFI_FEATURES) {
     $payjoinFfiFeatures = $env:PAYJOIN_FFI_FEATURES
 } else {
-    # Keep parity with other language test scripts: include _test-utils by default.
-    $payjoinFfiFeatures = "_test-utils"
+    # Include test utilities and manual TLS by default so local test services
+    # can fetch OHTTP keys over HTTPS with their generated self-signed cert.
+    $payjoinFfiFeatures = "_test-utils,_manual-tls"
 }
 
 if ($payjoinFfiFeatures) {

payjoin-ffi/csharp/scripts/generate_bindings.sh

@@ -22,8 +22,9 @@ SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 cd "$SCRIPT_DIR/../.."
 
 echo "Generating payjoin C#..."
-# Keep parity with other language test scripts: include _test-utils by default.
-PAYJOIN_FFI_FEATURES=${PAYJOIN_FFI_FEATURES:-_test-utils}
+# Include test utilities and manual TLS by default so local test services
+# can fetch OHTTP keys over HTTPS with their generated self-signed cert.
+PAYJOIN_FFI_FEATURES=${PAYJOIN_FFI_FEATURES:-_test-utils,_manual-tls}
 GENERATOR_FEATURES="csharp"
 if [[ -n $PAYJOIN_FFI_FEATURES ]]; then
     GENERATOR_FEATURES="$GENERATOR_FEATURES,$PAYJOIN_FFI_FEATURES"

payjoin-ffi/src/io.rs

@@ -21,7 +21,7 @@ pub mod error {
 ///
 /// * `payjoin_directory`: The payjoin directory from which to fetch the ohttp keys.  This
 ///   directory stores and forwards payjoin client payloads.
-#[uniffi::export]
+#[uniffi::export(async_runtime = "tokio")]
 pub async fn fetch_ohttp_keys(
     ohttp_relay: &str,
     payjoin_directory: &str,
@@ -43,6 +43,7 @@ pub async fn fetch_ohttp_keys(
 ///
 /// * `cert_der`: The DER-encoded certificate to use for local HTTPS connections.
 #[cfg(feature = "_manual-tls")]
+#[uniffi::export(async_runtime = "tokio")]
 pub async fn fetch_ohttp_keys_with_cert(
     ohttp_relay: &str,
     payjoin_directory: &str,