Olyx Guardrails

olyx-guardrails is a Ruby gem for checking text before you send it to a model and after you receive a complete response. Its pattern checks run inside your application. Rails applications can add the adapters described in this section.

This section documents the 1.2 release line. See the project changelog for release changes.

Capabilities

Capability	Application entry point
Input decisions	Olyx::Guardrails.check
Structured messages and adjacent-turn detection	Olyx::Guardrails.check_messages
Completed-output decisions	Olyx::Guardrails.check_output
PII, secret, and restricted-content redaction	Olyx::Guardrails.redact and .redact_output
Organization-specific restrictions	Immutable Policy and PolicyRule objects
Optional semantic analysis	Application-owned llm_provider callable
Rails enforcement and telemetry	Opt-in boundary adapters and Active Support events

Checking and redaction are separate operations

Decision methods return an allow/block result. They do not modify content. Redaction methods return transformed text and do not make an allow/block decision. Call both operations explicitly when your workflow requires both.

Requirements

Component	Supported versions
Ruby	3.4 or newer
Rails, when used	8.0 and 8.1

The gem uses the bundled base64 gem as its only runtime gem dependency. The framework-free API does not load Rails.

Check and redact

require "olyx/guardrails"

input = "Contact ada@example.com"
decision = Olyx::Guardrails.check(input)
puts decision[:allowed] # true: default policy reports PII without blocking
puts Olyx::Guardrails.redact(input)[:text] # Contact [EMAIL]

Start building

• Quickstart: install the gem and evaluate your first input.
• Policies: configure blocking, monitoring, replacements, and YAML.
• Rails integration: protect controllers, jobs, GraphQL, Action Cable, uploads, and model attributes.
• Operations: choose failure modes, notifications, and production behavior.
• Ruby API: verify exact signatures, result structures, and exceptions.

Application boundaries

Call Guardrails before sending text to a model and before returning a completed response to the caller. Your application makes the model call and handles access control, file reading, streaming, and saved audit records. To check a response before anyone sees it, collect the complete response, check it, and then return it.

You can use the gem with an application that calls Olyx CLI server mode or any other model client. Configure and invoke Guardrails in your application; it is a separate package and does not change the CLI’s configured route selection.

Pattern detection has documented coverage limits and can miss novel or encoded attacks. Read detection limits before choosing production enforcement behavior.

Project resources

• Source and examples
• RubyGems package
• Security reporting

Olyx Guardrails is licensed under Apache-2.0.