Inference regions

[ESegundoRolon]

What this does

Support region-aware inference profiles for AWS Bedrock

Problem

The current implementation hardcodes us. prefix for all Bedrock inference
profile models, causing failures when using cross-region inference in
non-US regions like EU, AP, or CA.

• Error encountered:
  The provided model identifier is invalid. (RubyLLM::BadRequestError)

This occurs because:

1. EU regions expect for example eu.anthropic.claude-sonnet-4-20250514-v1:0
2. But the library sends us.anthropic.claude-sonnet-4-20250514-v1:0
3. AWS Bedrock rejects the incorrect region prefix

Solution

Updated model_id_with_region method to dynamically extract the region
prefix from the configured bedrock_region:

• eu-west-3 → eu. prefix
• us-east-1 → us. prefix
• ap-south-1 → ap. prefix
• ca-central-1 → ca. prefix

Changes Made

Core Fix

File: lib/ruby_llm/providers/bedrock/models.rb

• Modified model_id_with_region to use dynamic region prefix
• Added inference_profile_region_prefix helper method
• Uses first two characters of bedrock_region as prefix
• Maintains backwards compatibility with us default

Tests Added

File: spec/ruby_llm/providers/bedrock/models_spec.rb

• Comprehensive tests for different AWS regions (US, EU, AP, CA)
• Tests for edge cases (empty/nil regions)
• Tests for both inference profile and on-demand models
• Ensures backwards compatibility

Testing

• ✅ US regions continue to work (us. prefix)
• ✅ EU regions now work (eu. prefix)
• ✅ AP/CA regions supported (ap./ca. prefixes)
• ✅ ON_DEMAND models unaffected
• ✅ Backwards compatible with existing configurations

Breaking Changes

None. This change is fully backwards compatible.

Type of change

• Bug fix
• New feature
• Breaking change
• Documentation
• Performance improvement

Scope check

• I read the Contributing Guide
• This aligns with RubyLLM's focus on LLM communication
• This isn't application-specific logic that belongs in user code
• This benefits most users, not just my specific use case

Quality check

• I ran overcommit --install and all hooks pass
• I tested my changes thoroughly
• I updated documentation if needed
• I didn't modify auto-generated files manually (models.json, aliases.json)

API changes

• Breaking change
• New public methods/classes
• Changed method signatures
• No API changes