Spin (Fermyon Cloud)

Spin is an open-source framework for building and running serverless WebAssembly applications.

Features

• Component Model: Uses WebAssembly Component Model
• Open Source: Run anywhere that supports Spin
• Fermyon Cloud: Managed hosting platform
• Key-Value Store: Built-in KV storage (TBA)
• SQLite: Embedded database (TBA)

Project Setup

Generate a new Spin project:

uzumibi new --template spin my-app
cd my-app

Configuration

Edit spin.toml:

spin_manifest_version = 2

[application]
name = "my-app"
version = "0.1.0"
authors = ["Your Name <your.email@example.com>"]

[[trigger.http]]
route = "/..."
component = "my-app"

[component.my-app]
source = "target/wasm32-wasi/release/my_app.wasm"
allowed_outbound_hosts = []
[component.my-app.build]
command = "cargo build --target wasm32-wasi --release"

Local Development

# Build and run
spin build
spin up

Deployment

Deploy to Fermyon Cloud:

spin login
spin deploy

Or run on your own infrastructure using any Spin-compatible runtime.

Limitations

• Execution Time: Platform-dependent
• Memory: Platform-dependent
• Component Model: Uses newer WASI preview 2 (compatibility varies)

Platform-Specific Features

• Access to Spin KV Store (TBA)
• Access to SQLite (TBA)
• Redis integration (TBA)