Bamboo is a mature, well-architected Elixir library for composing and delivering emails through adapters. It provides a clean functional API for building email structs, a powerful address normalization system via the `Bamboo.Formatter` protocol, and built-in adapters for Mailgun, Mandrill, SendGrid, local in-memory storage, and testing. The library supports background delivery, email interceptors, attachments, plug-based preview of sent emails, and comprehensive test helpers. Production code is separated from optional Phoenix view integration (extracted to bamboo_phoenix). The architecture uses behaviours for adapters and delivery strategies, making it extensible. It is actively maintained, with recent commits and CI passing on Elixir 1.17-1.19.
Bandit is a production-grade HTTP server library for Elixir, implementing HTTP/1 (RFC 9112), HTTP/2 (RFC 9113), and WebSocket (RFC 6455) protocols. It is built on the Thousand Island connection management library and serves as the default HTTP server for the Phoenix web framework (since version 1.7.11). The library is designed for correctness, security, and performance, achieving 100% conformance in the h2spec (HTTP/2) and Autobahn (WebSocket) test suites, while outperforming alternatives like Cowboy in benchmark comparisons. Architecturally, Bandit uses a protocol-sniffing initial handler that dispatches incoming connections to either an HTTP/1 or HTTP/2 handler based on the client preface. HTTP/2 connections follow a process-per-connection model with a separate stream process for each concurrent request, while HTTP/1 and WebSocket connections operate within a single process. The library exposes a small public API centered on the `Bandit` module, which validates options and delegates to Thousand Island. Internally, it defines clear abstractions such as the `Bandit.HTTPTransport` protocol for shared transport logic, a reusable `Bandit.Extractor` state machine for frame parsing, and telemetry spans for observability. Key features include support for HTTP/1 keepalive, HTTP/2 flow control and HPACK header compression, WebSocket permessage-deflate compression, content-encoding negotiation (gzip, deflate, zstd), Unix socket binding, and comprehensive error handling with clear RFC citations. The library is actively maintained with frequent releases addressing security vulnerabilities and edge cases, and includes extensive CI workflows for conformance testing, benchmarking, and regression prevention.
TeslaMate is a self-hosted data logger for Tesla vehicles that collects telemetry via the Tesla API (both polling and streaming), stores data in PostgreSQL, and provides visualization through a Phoenix LiveView web interface and Grafana dashboards. It integrates with home automation systems via MQTT and supports importing historical vehicle data from CSV files (TeslaFi format). The application uses a supervision tree to manage background processes for data collection, MQTT publishing, import tasks, and update checking. Key features include geofencing for location-based cost tracking, encrypted storage for API tokens using Cloak, internationalization via Gettext, and custom Ecto expressions for geographic calculations. The architecture is monolithic with clear separation of concerns through Phoenix contexts (Log, Vehicles, Settings, Locations).
Operately is an open-source company operating system for coordinating goals, projects, and teams. It provides a full collaboration suite including spaces (groups), goals with OKRs, project management with milestones and tasks, check-in cadence, retrospectives, discussions, document and file management (Resource Hubs), KPI tracking, and people management. The system is built as a monolith with a Phoenix (Elixir) backend serving a custom TurboConnect API (mutation/query protocol) and a React/TypeScript single-page application frontend with a reusable component library (turboui). It also offers a CLI tool, Model Context Protocol (MCP) integration for AI agents, and extensive background job processing via Oban for notifications, email delivery, search indexing, and billing operations. The architecture follows a clean domain-driven design with operations (Ecto.Multi transactions), activity logging (event sourcing with embedded schemas), an access control system with hierarchical groups and bindings, and a rich content editor with link enrichment and blob storage. The codebase is well-tested with both backend (ExUnit, Wallaby) and frontend (Jest, React Testing Library) tests, and includes a demo data builder for development. The enterprise edition (ee/) extends the core with SaaS admin capabilities, billing management via Polar, site messages, and feature flags. The system has evolved significantly with over 115 data migrations, indicating active development. While the core architecture is solid and many patterns are reusable, there are some incomplete features (e.g., stubbed notification handlers, missing email templates) and occasional code duplication between internal API and MCP tool layers. Overall, it demonstrates strong engineering craftsmanship with practical trade-offs for an open-source SaaS application.
Caclawphony is an Elixir/OTP application that automates pull request triage, review, and merging by orchestrating AI agents (Codex). It polls a Linear project board for issues in configured states, creates isolated workspaces per issue, and runs phase-specific agent prompts (triage, review, prepare, merge, closure). A real-time terminal dashboard and optional Phoenix LiveView web UI provide observability into running agents, token usage, and rate limits. The system is driven by a single WORKFLOW.md file that serves as both configuration (YAML front matter) and per-issue prompt template. The architecture follows OTP GenServer patterns: an orchestration loop polls the tracker, dispatches to AgentRunner instances that manage Codex subprocesses via stdin/stdout JSON-RPC, and reconciles state transitions. External integrations include the Linear GraphQL API, GitHub CLI for PR operations, and Telegram for notifications. The repository includes extensive test coverage, CI/CD workflows, and reusable patterns such as a tracker behaviour, snapshot testing support, and a spec coverage linting mix task. While designed for the openclaw/openclaw repository with hardcoded Linear identifiers and defaults, the plugin architecture (tracker adapters, workspace hooks, prompt templates) supports customization. The codebase is actively maintained with modern Elixir tooling (Phoenix, Bandit, NimbleOptions) and demonstrates solid software engineering practices, though its tight coupling to specific Linear states and the prototype nature noted in README limit immediate reuse outside the originating project.