lex-bedrock

Legion Extension that connects LegionIO to AWS Bedrock for foundation model inference.

Purpose

Wraps the AWS Bedrock SDK as named runners consumable by any LegionIO task chain. Provides the Converse API (multi-turn chat), raw InvokeModel (direct model invocation), and foundation model listing. Uses the AWS SDK directly — no Faraday. Use this extension when you need direct access to the Bedrock API surface within the LEX runner/actor lifecycle. For simple chat/embed workflows, consider legion-llm instead.

Installation

Add to your Gemfile:

gem 'lex-bedrock'

Configuration

AWS credentials are required:

• access_key_id — AWS access key ID
• secret_access_key — AWS secret access key
• region — AWS region (default: us-east-2)
• session_token — optional, for assumed roles

Usage

Standalone Client

client = Legion::Extensions::Bedrock::Client.new(
  access_key_id: 'AKIA...',
  secret_access_key: 'secret',
  region: 'us-east-2'
)

# List foundation models
result = client.list
# => { models: [...] }

# Converse API
result = client.create(
  model_id: 'anthropic.claude-3-5-sonnet-20241022-v2:0',
  messages: [{ role: 'user', content: [{ text: 'Hello' }] }]
)
# => { result: ..., usage: ..., stop_reason: 'end_turn' }

# Raw InvokeModel
result = client.invoke_model(
  model_id: 'anthropic.claude-3-5-sonnet-20241022-v2:0',
  body: { prompt: 'Hello', max_tokens: 256 }
)
# => { result: { ... }, content_type: 'application/json' }

Runner Modules

include Legion::Extensions::Bedrock::Runners::Models
include Legion::Extensions::Bedrock::Runners::Converse
include Legion::Extensions::Bedrock::Runners::Invoke

API Coverage

Runner	Methods
Converse	create
Invoke	invoke_model
Models	list, get

Related

• lex-claude — Direct Anthropic API client (bypasses Bedrock)
• legion-llm — High-level LLM interface including Bedrock via ruby_llm
• extensions-ai/CLAUDE.md — Architecture patterns shared across all AI extensions

License

MIT