Omnia Wasm Runtime

The Omnia Wasm runtime provides a thin wrapper around wasmtime for ergonomic integration of host-based services for WASI components.

It allows you to declaratively assemble a runtime that provides specific capabilities (like HTTP, Key-Value, Messaging) to guest components, backed by real host implementations.

Quick Start

Use the runtime! macro to configure which WASI interfaces and backends your host runtime needs. This generates a runtime_run function that handles the entire lifecycle.

use omnia::runtime;
use omnia_wasi_http::WasiHttpCtx;
use omnia_wasi_keyvalue::KeyValueDefault;
use omnia_wasi_otel::DefaultOtel;

// Define the runtime with required capabilities
omnia::runtime!({
    "http": WasiHttpCtx,
    "keyvalue": KeyValueDefault,
    "otel": DefaultOtel,
});

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    // Parse command line arguments (provided by the macro-generated Cli)
    let cli = Cli::parse();

    // Run the runtime
    runtime_run(cli).await
}

Core Traits

The runtime is built around a set of traits that allow services to be plugged in:

Trait	Purpose
`Host<T>`	Links a WASI interface (e.g., `wasi:http`) into the `wasmtime::Linker`.
`Server<S>`	Starts a server (e.g., HTTP listener, NATS subscriber) to handle incoming requests.
`Backend`	Connects to an external service (e.g., Redis, Postgres) during startup.
`State`	Manages per-request state and provides access to the component instance.
`FromEnv`	Configures backend connections from environment variables.

Features

jit (default): Enables Cranelift JIT compilation, allowing you to run .wasm files directly. Disable this to only support pre-compiled .bin components (useful for faster startup in production).

Configuration

The runtime and its included services are configured via environment variables:

RUST_LOG: Controls logging verbosity (e.g., info, debug, omnia=trace).
OTEL_GRPC_URL: Endpoint for OpenTelemetry collector (if omnia-otel is used).

Architecture

See the workspace documentation for the full architecture guide and list of available WASI interface crates.

License

MIT OR Apache-2.0