The main purpose of this document is to establish the API for version 1.0 of the library.

The structure of the models will be different than what it is today.

• The activitypub module will be renamed to vocab and contain the vanilla types described in the Activity vocabulary specification.
• The processing module will become the new activitypub module, and it will contain the state machine for processing client to server and server to server activities.
  • It will include subpackages for convenience functionality to interop with the wider Go ecosystem: HTTP handlers
  • The authorization module moves as a subpackage here.
• The client module stays as is.

The vocabulary

Generating code should start from a Go struct with annotations.

The steps should be something like this:

Structure

We need to validate the struct’s compatibility with the Vanilla AP objects:

• the properties must match the position and type of one of the Object, Actor, IntransitiveActivity, Activity, Link, etc.
• the struct must validate against the JSON-LD contexts that the developer chooses for them.

Helper functions

Generate helper functions:

• Initializer function: New<Type>
• Generate functions: On<StructName>, and To<StructName>
• Generate function type With<Type>Fn
• Generate MarshalJSON/UnmarshalJSON, GobEncode/GobDecode
• Add type switch cases to the IsObject, IsActor, IsActivity, IsIntransitiveActivity, IsLink
• Add type switch cases to the ToObject, ToActor, ToActivity, ToIntransitiveActivity, ToLink
• Add type switch cases to the IsNil function.

Types

Accumulate types for generated objects and add their types to the slices for:

• ActorTypes: struct has Inbox/Outbox properties
• ActivityTypes: struct has Actor/Object properties
• IntransitiveActivityTypes: struct has Actor property but no Object property
• LinkTypes: no ID property, but has a Href property.
• ObjectTypes: what’s left?

Accumulate types into the interfaces that can be used by generic code (Actors, Objects, etc).