Composition

WebAssembly Composition with Hayride

Hayride supports composing modular WebAssembly components using WAC, a tool developed by the Bytecode Alliance. This enables developers to break down complex applications into smaller, reusable components that expose their functionality through WIT interfaces.

These components can then be composed into a complete application that runs on the Hayride runtime.

tip

For more tools related to WebAssembly composition, see the Tools Reference.

Hayride CLI Integration with WAC

Hayride includes native support for WAC commands in its CLI, providing a streamlined developer experience for composing and managing components via the Hayride registry.

hayride wac plug

The plug command provides a fast way to wire together components by resolving interfaces (sockets) and implementations (plugs) automatically.

Components are fetched from the Hayride registry using a package reference.

Example

To plug the hayride core cfg component into the appropriate import of the hayride core server component:

hayride wac plug --socket hayride-core:server@0.0.1 --plugs hayride-core:cfg@0.0.1

This automatically connects the cfg component to the matching interface to produce a full component.

hayride wac compose

The compose command allows you to build more complex applications by explicitly defining how multiple components are connected using a WAC composition file.

Components are fetched from the Hayride registry using a package reference.

Example Composition File

Below is a WAC composition file for a cli that use Hayride AI imports for context, model, tools, and agents components, and exports a complete cli component:

package hayride:agent;

let context = new hayride:inmemory@0.0.1 {...};

let llama = new hayride:llama31@0.0.1 {...};

let tools = new hayride:default-tools@0.0.1 {...};

let agent = new hayride:default-agent@0.0.1 {
  context: context.context,
  model: llama.model,
  tools: tools.tools,
  ...
};

let cli = new hayride:cli@0.0.1 {
  context: context.context,
  model: llama.model,
  tools: tools.tools,
  agents: agent.agents,
  ...
};

// Export the cli
export cli...;

Building the Composed Component

To build the composed component into a standalone .wasm file:

hayride wac compose --path default-agent-cli.wac --out cli.wasm

This will resolve all referenced components, apply the specified wiring, and produce a deployable cli.wasm.