Rails Error Dashboard (RED) is an open-source, self-hosted Rails engine for investigating production exceptions without sending error data to a monitoring vendor. It groups errors and records request context and cause chains and, when enabled, breadcrumbs plus local and instance variables captured before Ruby unwinds the stack. RED attaches Rails and Ruby runtime health to the error record on every captured occurrence, including Active Record pool, Puma, background jobs, GC, memory, threads, file descriptors and system pressure. Built-in storm protection progressively sheds expensive context and I/O during error floods while retaining useful exemplars and exact occurrence counts. Run RED with your application's database or an isolated error database. It supports PostgreSQL, MySQL/Trilogy and SQLite, and includes workflow, notifications (Slack, Email, Discord, PagerDuty, webhooks), two-way issue sync with GitHub, GitLab, Codeberg and Linear, Copy as RSpec/curl/LLM, swallowed-exception detection, LLM observability without prompt capture, OpenTelemetry span export and Rails-specific operational views. The dashboard is translated into 11 languages (machine-translated outside English, awaiting native review). A self-hosted Sentry alternative that keeps error data in your own database. The gem is MIT and free forever. Supports Rails 7.0-8.1 and Ruby 3.2-4.0. Beta: APIs may change before 1.0. Live demo: https://rails-error-dashboard.anjan.dev