Chronos Ruby

Chronos Ruby is the framework-independent client for sending Ruby application errors to Chronos. Version 0.1 is the legacy foundation: it captures exceptions manually, builds a bounded JSON event, and delivers it synchronously or through a fixed-size asynchronous queue.

What the gem collects

For each exception, version 0.1 can collect:

exception class, message, structured backtrace, and chained causes;
timestamp, severity, tags, and an optional fingerprint;
application-supplied context, parameters, session, and user fields;
Ruby version, engine, platform, process ID, opaque thread ID, and hostname;
application version, environment, and service name.

See Data collected for the complete field table.

What is not collected by default

Chronos Ruby does not inspect environment variables, request bodies, cookies, HTTP headers, source code, database contents, or installed gems. Version 0.1 does not automatically sanitize application-supplied context. Do not pass passwords, tokens, cookies, personal documents, or payment data. Advanced redaction belongs to version 0.2.

Supported Ruby and Rails versions

Version 0.x targets Ruby 2.2.10 through Ruby 2.6. Version 0.1 is independent of Rails and does not yet declare support for any Rails integration. All supported combinations must pass dedicated CI before being listed as supported.

See Compatibility.

Plain Ruby installation

The current public build is a pre-release. Add its exact version to the application's Gemfile:

gem "chronos-ruby", "0.1.0.pre.2"

Install with a Bundler version compatible with the application. For the oldest supported runtime:

gem install bundler -v 1.17.3
bundle _1.17.3_ install

Without Bundler:

gem install chronos-ruby --pre

Rails installation

Rails automatic integration is not part of version 0.1. A Rails application may use the plain Ruby API, but this does not constitute declared Rails support. Rack and Rails adapters are planned for later legacy releases.

Minimum configuration

project_id, project_key, and an HTTPS host are required while the agent is enabled:

require "chronos"

Chronos.configure do |config|
  config.project_id = ENV["CHRONOS_PROJECT_ID"]
  config.project_key = ENV["CHRONOS_PROJECT_KEY"]
  config.host = "https://chronos.example.com"
  config.environment = ENV["APP_ENV"] || "production"
  config.service_name = "billing"
  config.app_version = ENV["APP_VERSION"]
end

HTTPS verification is enabled by default. HTTP requires explicitly setting ssl_verify = false and should only be used with a local test server.

Automatic capture

Automatic exception capture is not implemented in version 0.1. Applications must call Chronos.notify or Chronos.notify_sync. Rack, Rails, and worker hooks will be introduced only after their compatibility suites exist.

Manual capture

Asynchronous capture is recommended for application code:

begin
  perform_payment
rescue StandardError => error
  Chronos.notify(error, :tags => ["payment"])
  raise
end

Synchronous capture waits for the HTTP result and is useful in scripts or controlled shutdown paths:

delivered = Chronos.notify_sync(RuntimeError.new("import failed"))

Both methods return false instead of allowing an internal agent error to escape.

User context

User data is opt-in and must contain only values your application is allowed to send:

Chronos.notify(error, :user => {"id" => "customer-42", "role" => "operator"})

Avoid names, e-mail addresses, documents, tokens, and other personal or secret fields in version 0.1.

Breadcrumbs are not implemented in version 0.1.

Filters and LGPD

Version 0.1 limits depth, collection length, string length, backtrace length, and total payload size. It does not provide the recursive sensitive-data filter planned for version 0.2. Review all supplied context before production use. See Privacy and LGPD.

Ignore rules

Entire environments can be ignored:

Chronos.configure do |config|
  # required options omitted
  config.ignored_environments = ["development", "test"]
end

Exception-specific ignore rules are not available in version 0.1.

Performance monitoring

Request, SQL, cache, job, and external HTTP monitoring are not implemented in version 0.1. The local capture pipeline is bounded and HTTP delivery runs outside the caller thread when Chronos.notify is used.

Sidekiq and Active Job

Sidekiq and Active Job integrations are not implemented in version 0.1. Calling the manual API from a job is possible, but automatic capture and deduplication are not yet guaranteed.

Deploy tracking

Deploy notifications are not implemented in version 0.1. app_version may be included in exception events for release correlation.

Asynchronous queue

The queue has a fixed capacity and drops the newest event when full. Worker threads are created lazily after the first accepted event. The default capacity is 100 events with one worker.

flowchart LR
  E[Exception] --> N[Notice builder]
  N --> S[Bounded serializer]
  S --> Q[Bounded queue]
  Q --> W[Fixed worker pool]
  W --> H[Net::HTTP transport]

Use Chronos.flush(timeout) to wait for accepted events and Chronos.close(timeout) during shutdown. Workers are recreated after a process fork.

Retry and backlog

Version 0.1 classifies network failures, 429, 4xx, and 5xx, but does not retry or persist events. Failed deliveries are dropped after the attempt. Bounded retry and backlog are planned for version 0.3.

How it works internally

The code follows hexagonal boundaries:

Chronos::Core contains immutable notices and normalization;
Chronos::Application coordinates capture;
Chronos::Ports defines delivery behavior;
Chronos::Adapters implements Net::HTTP delivery;
Chronos::Internal owns bounded queueing, workers, and defensive logging.

The core has no dependency on Rails, Rack, Sidekiq, or ActiveSupport. See Architecture.

Environment-specific configuration

Configuration values are explicit; the gem never scans the process environment. Read only the variables your application chooses:

Chronos.configure do |config|
  config.project_id = ENV["CHRONOS_PROJECT_ID"]
  config.project_key = ENV["CHRONOS_PROJECT_KEY"]
  config.host = ENV["CHRONOS_HOST"]
  config.environment = ENV["APP_ENV"] || "production"
  config.enabled = ENV["CHRONOS_ENABLED"] != "false"
  config.queue_size = 100
  config.workers = 1
  config.timeout = 5.0
  config.open_timeout = 2.0
end

All options are documented in Configuration.

Troubleshooting

Configuration errors are raised during Chronos.configure. Capture and delivery errors are contained and optionally reported to the configured logger. Verify credentials, HTTPS certificates, timeouts, and Chronos.flush results. See Troubleshooting.

Benchmark

Run the version 0.1 benchmarks with:

bundle _1.17.3_ exec ruby benchmarks/capture_exception.rb
bundle _1.17.3_ exec ruby benchmarks/serialization.rb
bundle _1.17.3_ exec ruby benchmarks/queue.rb

Results depend on runtime, hardware, and payload. No performance comparison is claimed until repeatable measurements are published.

Migration from Airbrake

An Airbrake migration guide will be added before the legacy 1.0 release. Version 0.1 does not claim API compatibility or automatic replacement.

Local development

Clone the repository, install Bundler 1.17.3, and run setup:

gem install bundler -v 1.17.3
bin/setup

Open an interactive console:

bin/console

Install the current source locally:

bundle _1.17.3_ exec rake install

Tests

Run the complete suite on the current Ruby:

bundle _1.17.3_ exec rake

The legacy CI matrix covers Ruby 2.2.10, 2.3.8, 2.4.10, 2.5.9, and 2.6.10. Network integration tests use a local fake HTTP server.

Contributing

Open an issue before introducing a new public API or dependency. Every public class requires YARD documentation, tests, module documentation, and compatibility evidence. See CONTRIBUTING.md.

Security

Never include credentials in event context or logs. Report vulnerabilities privately according to SECURITY.md. Ruby 2.2 through 2.6 are end-of-life; Chronos provides technical compatibility, not runtime security maintenance.

License

Chronos Ruby is distributed under the terms of the MIT License. See LICENSE.txt.