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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 can be fetched from the Hayride registry using a package reference.

Example

To plug a datetime utility into the appropriate import of an AI agent component:

hayride wac plug --socket agent.wasm --plugs hayride:datetime@0.0.1

This automatically connects the datetime component to the matching interface in the agent.wasm 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.

Registered Hayride components can be referenced using their package names and versions.

Example Composition File

Below is a WAC composition file for an AI agent that connects memory, model, and datetime components, and exports a complete server:

package hayride:agent;

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

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

let datetime = new hayride:datetime@0.0.1 {...};

let agent = new hayride:basic@0.0.1 {
  context: context.context,
  model: llama.model,
  datetime: datetime.datetime,
  ...
};

let server = new hayride-core:ai-server-cfg@0.0.1 {
  agent: agent.agent,
  ...
};

// Export the server handler and config
export server...;

Building the Composed Component

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

hayride wac compose --path basic-agent.wac --out server.wasm

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