Orator - OpenAI API to ActivityPub Gateway

Orator converts between OpenAI-like APIs (OpenResponses, ChatCompletion) and ActivityPub federation protocol, enabling AI agents to communicate via ActivityPub.

Overview

#+name: orator
require "translator"
require "translator/registry"

settings do
  data.adapter = "memory"
  port = 8080
end

struct InputSchema
  include Api::OpenResponses::Request
  include Api::ChatCompletionAPI::Request
  include Api::Models
end

struct OutputSchema
  include Api::OpenResponses::Response
  include Api::ChatCompletionAPI::Response
end

@[Container(static)]
@[Load(".env")]
@[Validate(InputSchema, OutputSchema)]
workflow "orator" do
  follow ["@actra@lefine.pro"]

  send_to_inbox

  recevie_from_outbox
end

Architecture

┌─────────────────┐
│ OpenAI Request  │  (POST /v1/responses or /v1/chat/completions)
│ OpenResponses   │
│ ChatCompletion  │
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│ send_to_inbox   │  Convert to ActivityPub Create{Ticket}
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│ ActivityPub     │  ForgeFed Ticket via Aptok
│ Inbox/Outbox    │
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│ receive_from_   │  Convert back to OpenAI format
│ outbox          │
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│ OpenAI Response │
│ OpenResponses   │
│ ChatCompletion  │
└─────────────────┘

Components

** translators/

• converters.cr - OpenAI ↔ ActivityPub conversion logic
• translators.cr - Ocawe node kind implementations (SendToInbox, ReceiveFromOutbox)
• registry.cr - Registers custom node kinds with Ocawe::RegistryApi.node_kind()

Uses Aptok helpers: Aptok.forgefed_ticket() and Aptok.create()

Usage

cd orator
ocawe up

Then send requests to:

• GET http://localhost:8080/v1/models - List available models
• POST http://localhost:8080/v1/responses - OpenResponses format
• POST http://localhost:8080/v1/chat/completions - ChatCompletion format

Requirements

• Ocawe framework (workflows, federation, node registry)
• Aptok library (ActivityPub helpers)

Deployment

** Container

The project includes GitHub Actions CI/CD to build and publish containers:

# Pull from GitHub Container Registry
docker pull ghcr.io/lefinepro/orator:latest

# Run the container
docker run -p 8080:8080 ghcr.io/lefinepro/orator:latest

** Building Locally

# Build with ocawe CLI
ocawe build --release --output build/ocawe

# Build Docker image
docker build -t orator:latest .

** CI/CD

The .github/workflows/container.yml workflow automatically:

• Builds multi-platform containers (linux/amd64, linux/arm64)
• Publishes to GitHub Container Registry
• Creates tags for branches, PRs, and semantic versions