openab: Instructions file for Codex

OpenAB — Agent Guidelines

You are contributing to OpenAB, a lightweight Rust-based ACP harness bridging Discord, Slack, and webhook platforms to coding CLIs over stdio JSON-RPC.

Architecture

src/
├── main.rs           # entrypoint, multi-adapter startup, graceful shutdown
├── adapter.rs        # ChatAdapter trait, AdapterRouter (platform-agnostic)
├── config.rs         # TOML config + ${ENV_VAR} expansion
├── discord.rs        # DiscordAdapter (serenity EventHandler)
├── slack.rs          # SlackAdapter (Socket Mode)
├── gateway.rs        # Custom Gateway WebSocket adapter
├── cron.rs           # Config-driven + usercron scheduler
├── media.rs          # Image resize/compress + STT download
├── format.rs         # Message splitting, thread name shortening
├── markdown.rs       # Discord markdown rendering
├── reactions.rs      # Emoji status controller (debounce, stall detection)
├── bot_turns.rs      # Bot turn tracking
├── error_display.rs  # User-facing error formatting
├── stt.rs            # Speech-to-text (Whisper API)
├── setup/            # Interactive setup wizard
│   ├── config.rs     # Setup config helpers
│   ├── validate.rs   # Input validation
│   └── wizard.rs     # CLI setup flow
└── acp/
    ├── protocol.rs   # JSON-RPC types + ACP event classification
    ├── connection.rs # Spawn CLI, stdio JSON-RPC, env_clear whitelist
    └── pool.rs       # Session key → AcpConnection map + lifecycle

Helm chart: charts/openab/ — Go templates, values.yaml, NOTES.txt Gateway: gateway/ — standalone Rust binary for Telegram/LINE/Teams Docs: docs/ — user-facing guides, ADRs, config reference

Message Flow

Discord/Slack event
  → channel allowlist check
  → user allowlist check (bot messages bypass this)
  → bot message filter (off/mentions/all)
  → thread detection (thread_metadata = thread, NOT parent_id)
  → bot ownership check (bot_owns = thread creator matches bot user ID)
  → multibot detection (allowUserMessages mode)
  → handle_message → pool.get_or_create → ACP JSON-RPC