ludfjig · Oct 15, 2026 · Oct 15, 2026 · Oct 15, 2026 · Oct 15, 2026
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
@@ -36,3 +36,11 @@ updates:
     target-branch: "main"
     labels:
       - "kind/dependencies"
+  - package-ecosystem: "nuget"
+    directory: "/dotnet"
+    schedule:
+      interval: "daily"
+      time: "03:00"
+    target-branch: "main"
+    labels:
+      - "kind/dependencies"
diff --git a/.gitignore b/.gitignore
@@ -457,6 +457,7 @@ $RECYCLE.BIN/
 ## Hyperlight
 
 **/include/hyperlight*.h
+!src/hyperlight_wasm_capi/include/hyperlight_wasm.h
 **/include/printf.h
 **/native/HyperlightGuest.lib
 **/native/HyperlightGuest.pdb

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,20 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Prerelease] - Unreleased
 
+### Added
+
+- Added the `hyperlight-wasm-capi` crate, a C API that calls component functions with arguments and results encoded in hyperlight's component wire format.
+- Added the `Hyperlight.Wasm` and `Hyperlight.Wasm.Build` .NET packages. They run components from .NET with typed C# bindings generated from WIT at build time. See `dotnet/README.md`.
+- Added `SandboxBuilder::with_runtime_file` to load the guest runtime from a file, and `SandboxBuilder::with_interrupt_vcpu_sigrtmin_offset` to change the interrupt signal on Linux.
+
+### Changed
+
+- **BREAKING CHANGE:** Component functions use hyperlight's wire names and little-endian encoding, so hosts and guests built with earlier versions cannot call each other.
+
+### Fixed
+
+- Wasm traps report an error instead of aborting the guest with a general protection fault.
+
 ## [v0.15.0] - 2026-08
 
 ### Changed

diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -1,5 +1,5 @@
 [workspace]
-members = [ "src/hyperlight_wasm", "src/examples_common", "src/hyperlight_wasm_aot", "src/hyperlight_wasm_runtime", "src/hyperlight_wasm_macro" ]
+members = [ "src/hyperlight_wasm", "src/hyperlight_wasm_capi", "src/hyperlight_wasm_bindgen", "src/examples_common", "src/hyperlight_wasm_aot", "src/hyperlight_wasm_runtime", "src/hyperlight_wasm_macro" ]
 exclude = [ "src/tests/rust_guests/rust_wasm_samples", "src/tests/rust_guests/component_sample", "src/tests/rust_guests/greeter_sample" ]
 resolver = "2"
 
@@ -15,9 +15,24 @@ readme = "README.md"
 [workspace.dependencies]
 hyperlight-common = { version = "0.18.0", default-features = false }
 hyperlight-component-macro = "0.18.0"
+hyperlight-component-csharp = "0.18.0"
 hyperlight-component-util = "0.18.0"
 hyperlight-guest = "0.18.0"
 hyperlight-guest-bin = "0.18.0"
 hyperlight-host = { version = "0.18.0", default-features = false }
 hyperlight-wasm-macro = { version = "0.15.0", path = "src/hyperlight_wasm_macro" }
 hyperlight-wasm-runtime = { version = "0.15.0", path = "src/hyperlight_wasm_runtime" }
+
+# Unreleased hyperlight with the component wire format and C# bindings.
+# Remove once hyperlight releases these changes.
+[patch.crates-io]
+hyperlight-host = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-common = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-guest = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-guest-bin = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-guest-macro = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-guest-tracing = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-libc = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-component-macro = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-component-util = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
+hyperlight-component-csharp = { git = "https://github.com/hyperlight-dev/hyperlight", branch = "component-wire-format" }
diff --git a/Justfile b/Justfile
@@ -124,6 +124,22 @@ examples-components target=default-target features="": (build-rust-component-exa
     {{ wit-world }} cargo run {{ if features =="" {''} else {"--no-default-features -F kvm -F " + features } }} --profile={{ if target == "debug" {"dev"} else { target } }} --example component_example
     {{ wit-world-c }} cargo run {{ if features =="" {''} else {"--no-default-features -F kvm -F " + features } }} --profile={{ if target == "debug" {"dev"} else { target } }} --example c-component
     {{ wit-world }} {{ wit-world-name-greeter }} cargo run {{ if features =="" {''} else {"--no-default-features -F kvm -F " + features } }} --profile={{ if target == "debug" {"dev"} else { target } }} --example component_greeter_example
+    {{ wit-world }} cargo test -p hyperlight-wasm-capi --profile={{ if target == "debug" {"dev"} else { target } }} -- --include-ignored
+
+# Builds the native libraries, and a guest runtime and component for the component_sample example world, for the .NET tests
+dotnet-test-assets target=default-target: (build-rust-component-examples target)
+    cargo build -p hyperlight-wasm-capi -p hyperlight-wasm-bindgen --profile={{ if target == "debug" {"dev"} else { target } }}
+    {{ wit-world }} cargo hyperlight build --profile={{ if target == "debug" {"dev"} else { target } }} --manifest-path src/hyperlight_wasm_runtime/Cargo.toml --target-dir target/component-sample-runtime --locked
+
+# Runs the .NET tests. Needs the .NET 8 SDK or later.
+dotnet-test target=default-target: (dotnet-test-assets target)
+    dotnet test dotnet/tests/Hyperlight.Wasm.Tests -c {{ if target == "debug" {"Debug"} else {"Release"} }}
+
+# Packs the .NET packages for this machine's runtime identifier into dotnet/artifacts
+dotnet-pack target="release":
+    cargo build -p hyperlight-wasm-capi -p hyperlight-wasm-bindgen --profile={{ if target == "debug" {"dev"} else { target } }}
+    dotnet pack dotnet/src/Hyperlight.Wasm -c {{ if target == "debug" {"Debug"} else {"Release"} }} -o dotnet/artifacts
+    dotnet pack dotnet/src/Hyperlight.Wasm.Build -c {{ if target == "debug" {"Debug"} else {"Release"} }} -o dotnet/artifacts
 
 # Test a component and a module compiled with pulley
 examples-pulley target=default-target features="": (build-pulley-rust-component-examples target features) (build-pulley-rust-wasm-examples target features)

diff --git a/README.md b/README.md
@@ -134,6 +134,13 @@ WIT_WORLD=</path/to/output.wasm>  HYPERLIGHT_COMPONENT_MACRO_DEBUG=/tmp/guest.rs
 HYPERLIGHT_COMPONENT_MACRO_DEBUG=/tmp/host.rs cargo build
 ```
 
+### Other languages
+
+* [`src/hyperlight_wasm_capi`](src/hyperlight_wasm_capi) is a C API. Its header is `include/hyperlight_wasm.h`.
+* [`dotnet`](dotnet) has .NET packages with C# bindings generated from WIT.
+
+Both load a guest runtime built for the component's world from a file.
+
 
 ## Code of Conduct