vocabulary:
  name: Spin Vocabulary
  description: >-
    Domain vocabulary for the Spin WebAssembly application framework by Fermyon,
    covering application manifest configuration, component architecture, trigger types,
    storage APIs, and cloud deployment terminology.
  version: "1.0"
  created: "2026-05-02"
  modified: "2026-05-02"
  tags:
    - WebAssembly
    - Microservices
    - Serverless
    - Fermyon

terms:
  - term: Spin
    definition: >-
      An open-source framework by Fermyon for building and running fast, secure, and
      composable cloud microservices using WebAssembly. Spin provides a developer
      experience for building event-driven serverless applications that compile to Wasm.
    synonyms: [Spin Framework, Fermyon Spin]
    related: [WebAssembly, Component, Trigger]

  - term: Component
    definition: >-
      The fundamental unit of a Spin application — a single WebAssembly module that
      handles a specific type of event (HTTP request, Redis message, cron job).
      Components are isolated, stateless, and have explicit access grants for
      outbound requests and storage.
    synonyms: [Wasm Component, Module]
    related: [Trigger, Source, Application]

  - term: Application
    definition: >-
      A collection of one or more Spin components described in a spin.toml manifest file.
      Applications define the component sources, triggers, variables, and resource
      access grants. Applications are deployed as OCI artifacts.
    synonyms: [Spin App]
    related: [Component, Manifest, spin.toml]

  - term: Trigger
    definition: >-
      The event source that invokes a Spin component. Supported triggers include
      HTTP (incoming HTTP requests), Redis (pub/sub messages), and Cron (scheduled
      execution). Each component declares its trigger type and routing configuration.
    values: [http, redis, cron]
    related: [Component, Route, Channel]

  - term: spin.toml
    definition: >-
      The TOML-format application manifest file that defines a Spin application's
      components, triggers, variables, and resource access configuration.
      spin_manifest_version 2 is the current format version.
    synonyms: [Manifest, Application Manifest]
    related: [Application, Component, Variable]

  - term: WebAssembly
    definition: >-
      A portable binary instruction format that provides a sandboxed execution
      environment for code compiled from languages like Rust, Go, Python, and C.
      Spin uses WebAssembly (specifically WASI) as its runtime substrate for
      secure, isolated component execution.
    synonyms: [Wasm, WASM]
    related: [WASI, Component, Sandbox]

  - term: WASI
    definition: >-
      WebAssembly System Interface — a standard API for WebAssembly modules to
      access system resources like files, clocks, and network interfaces.
      Spin uses WASI for component access to storage, configuration, and outbound
      HTTP within defined permission boundaries.
    synonyms: [WebAssembly System Interface]
    related: [WebAssembly, Spin, Component]

  - term: Key-Value Store
    definition: >-
      A Spin runtime API providing components with access to a persistent key-value
      storage service. Components must declare key_value_stores access in spin.toml.
      The default store is provided by the Spin runtime; production deployments use
      backing services like Redis or cloud managed stores.
    synonyms: [KV Store, Key Value Storage]
    related: [Component, SQLite, Storage]

  - term: SQLite
    definition: >-
      An embedded relational database accessible to Spin components via the SQLite
      storage API. Components must declare sqlite_databases access in spin.toml.
      Suitable for structured data within Spin applications.
    related: [Component, Key-Value Store, Storage]

  - term: Serverless AI
    definition: >-
      The Spin API for accessing AI inference models (e.g., Llama 2, CodeLlama)
      directly within Spin components. Components declare ai_models access in
      spin.toml and use the infer() SDK function. Supported by Fermyon Cloud
      and SpinKube deployments.
    synonyms: [Spin AI, LLM Inferencing]
    related: [Component, Llama, ai_models]

  - term: Outbound HTTP
    definition: >-
      The Spin API for making HTTP requests from within a component. Components
      must declare allowed outbound hosts in spin.toml under allowed_outbound_hosts
      to restrict egress to approved endpoints.
    related: [Component, allowed_outbound_hosts, HTTP Trigger]

  - term: Variable
    definition: >-
      A named configuration value for a Spin application that can be required or
      optional, with an optional default value. Secret variables are masked in
      logs. Variables are injected into components via the variables SDK API.
    synonyms: [Config Variable, App Variable]
    related: [spin.toml, Component, Secret]

  - term: SpinKube
    definition: >-
      A Kubernetes operator and runtime for deploying Spin applications natively
      on Kubernetes using the SpinApp CRD and containerd-shim-spin. Enables
      running Spin Wasm workloads alongside traditional container workloads.
    related: [Kubernetes, Spin, Deployment]

  - term: Fermyon Cloud
    definition: >-
      The managed cloud hosting platform by Fermyon for running Spin applications.
      Provides zero-configuration deployment via spin deploy with built-in key-value
      storage, SQLite, AI inferencing, and custom domains.
    synonyms: [Fermyon Platform]
    related: [Spin, Deployment, Serverless]