feat: add Nexus Gateway integration for expanded model access

This commit implements Nexus Gateway integration, allowing the chatbot to connect
to additional AI models through a centralized gateway service. Key additions include:

1. NexusGatewayClient for authentication and API communication:
   - OAuth token management with caching
   - Secure API request handling
   - Comprehensive error handling

2. NexusModelProvider implementation:
   - Model discovery through the gateway
   - Transformation of Nexus models to application format
   - Support for both chat and embedding models

3. Fixed adapter structure issues:
   - Added missing types.py with ModelProvider abstract base class
   - Created direct and nexus provider implementations
   - Fixed import errors with proper directory structure

4. Added comprehensive test coverage:
   - Unit tests for client authentication and API calls
   - Tests for model transformation logic
   - Error handling test cases

Author: Raul Cajias

.gitignore

@@ -461,3 +461,20 @@ lib/user-interface/react-app/src/graphql/subscriptions.ts
 /.project
 /.pydevproject
 /outputs.json
+
+# Hatch
+.hatch/
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+.env*
+.envrc.local
+.env.local
+node_modules
+.amazonq
+AmazonQ.md
+.DS_Store
+cdk-exports.json

.python-version

@@ -0,0 +1 @@
+3.9.18

README.md

@@ -1,82 +1,53 @@
-# Building RAG use cases with GenAI Chatbot on AWS
+# AWS GenAI LLM Chatbot
 
-[![Release Notes](https://img.shields.io/github/v/release/aws-samples/aws-genai-llm-chatbot)](https://github.com/aws-samples/aws-genai-llm-chatbot/releases)
-[![GitHub star chart](https://img.shields.io/github/stars/aws-samples/aws-genai-llm-chatbot?style=social)](https://star-history.com/#aws-samples/aws-genai-llm-chatbot)
-[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
+Enterprise-ready generative AI chatbot with RAG capabilities.
 
-[![Deploy with GitHub Codespaces](https://github.com/codespaces/badge.svg)](https://aws-samples.github.io/aws-genai-llm-chatbot/guide/deploy.html#deploy-with-github-codespaces)
+## Overview
 
-[![Full Documentation](https://img.shields.io/badge/Full%20Documentation-blue?style=for-the-badge&logo=Vite&logoColor=white)](https://aws-samples.github.io/aws-genai-llm-chatbot/)
+The AWS GenAI LLM Chatbot is a production-ready solution that enables organizations to deploy a secure, feature-rich chatbot powered by large language models (LLMs) with Retrieval Augmented Generation (RAG) capabilities.
 
-![sample](docs/about/assets/chabot-sample.gif "GenAI Chatbot on AWS")
+## Key Features
 
+- **Multiple LLM Support**: Amazon Bedrock (Claude, Llama 2), SageMaker, and custom model endpoints
+- **Nexus Gateway Integration**: Connect to Nexus Gateway for additional model access
+- **Comprehensive RAG Implementation**: Connect to various data sources for context-aware responses
+- **Enterprise Security**: Fine-grained access controls, audit logging, and data encryption
+- **Conversation Memory**: Full conversation history with persistent storage
+- **Web UI and API Access**: Modern React interface and API endpoints for integration
+- **Cost Optimization**: Token usage tracking and cost management features
+- **Deployment Flexibility**: Multiple deployment options to fit your needs
 
-## 🚀 NEW! Support for new Amazon Nova Models 🚀
-### Deploy this chatbot to use the recently announced [Amazon Nova models](https://aws.amazon.com/blogs/aws/introducing-amazon-nova-frontier-intelligence-and-industry-leading-price-performance/)!
-### These powerful models can __understand__ and __generate__ images and videos.
+## Getting Started
 
-Deploy this chatbot to experiment with:
-- `Amazon Nova Micro`
-- `Amazon Nova Lite`
-- `Amazon Nova Pro`
-- `Amazon Nova Canvas`
-- `Amazon Nova Reels`
+This blueprint deploys the complete AWS GenAI LLM Chatbot solution in your AWS account.
 
+### Prerequisites
 
+- AWS Account with appropriate permissions
+- AWS CLI configured with credentials
+- Node.js 18+ and npm
+- Python 3.8+
 
-Make sure to request access to the new models [here](https://aws-samples.github.io/aws-genai-llm-chatbot/documentation/model-requirements.html#amazon-bedrock-requirements)
+### Deployment
 
-Read more about the new models [here](https://www.aboutamazon.com/news/aws/amazon-nova-artificial-intelligence-bedrock-aws)
+The deployment process is fully automated using AWS CDK and SeedFarmer.
 
----
+## Architecture
 
+The solution architecture includes:
 
-This solution provides ready-to-use code so you can start **experimenting with a variety of Large Language Models and Multimodal Language Models, settings and prompts** in your own AWS account.
+- Amazon Bedrock for LLM access
+- Amazon OpenSearch for vector storage
+- Amazon S3 for document storage
+- Amazon Cognito for authentication
+- AWS Lambda for serverless processing
+- Amazon API Gateway for API access
+- React-based web interface
 
-Supported model providers:
+## Documentation
 
-- [Amazon Bedrock](https://aws.amazon.com/bedrock/) which supports a wide range of models from AWS, Anthropic, Cohere and Mistral including the latest models from Amazon Nova. See [Recent announcements](https://aws.amazon.com/blogs/aws/introducing-amazon-nova-frontier-intelligence-and-industry-leading-price-performance/) for more details.
-- [Amazon SageMaker](https://aws.amazon.com/sagemaker/) self-hosted models from Foundation, Jumpstart and HuggingFace.
-- Third-party providers via API such as Anthropic, Cohere, AI21 Labs, OpenAI, etc. [See available langchain integrations](https://python.langchain.com/docs/integrations/llms/) for a comprehensive list.
+For complete documentation, visit the [GitHub repository](https://github.com/aws-samples/aws-genai-llm-chatbot).
 
-# Additional Resources
+## License
 
-| Resource |Description|
-|:-------------|:-------------|
-| [Secure Messenger GenAI Chatbot](https://github.com/aws-samples/secure-messenger-genai-chatbot) | A messenger built on Wickr that can interface with this chatbot to provide Q&A service in tightly regulated environments (i.e. HIPAA). |
-| [Project Lakechain](https://github.com/awslabs/project-lakechain) | A powerful cloud-native, AI-powered, document (docs, images, audios, videos) processing framework built on top of the AWS CDK. |
-| [AWS Generative AI CDK Constructs](https://github.com/awslabs/generative-ai-cdk-constructs/) | Open-source library extension of the [AWS Cloud Development Kit (AWS CDK)](https://docs.aws.amazon.com/cdk/v2/guide/home.html)  aimed to help developers build generative AI solutions using pattern-based definitions for their architecture. |
-| [Artifacts and Tools for Bedrock](https://github.com/aws-samples/artifacts-and-tools-for-bedrock) | An innovative chat-based user interface with support for tools and artifacts. It can create graphs and diagrams, analyze data, write games, create web pages, generate files, and much more.  |
-
-# Roadmap
-
-Roadmap is available through the [GitHub Project](https://github.com/orgs/aws-samples/projects/69)
-
-# Authors
-
-- [Bigad Soleiman](https://www.linkedin.com/in/bigadsoleiman/)
-- [Sergey Pugachev](https://www.linkedin.com/in/spugachev/)
-
-# Contributors
-[![contributors](https://contrib.rocks/image?repo=aws-samples/aws-genai-llm-chatbot&max=2000)](https://github.com/aws-samples/aws-genai-llm-chatbot/graphs/contributors)
-
-# License
-
-This library is licensed under the MIT-0 License. See the LICENSE file.
-
-- [Changelog](CHANGELOG.md) of the project.
-- [License](LICENSE) of the project.
-- [Code of Conduct](CODE_OF_CONDUCT.md) of the project.
-- [CONTRIBUTING](CONTRIBUTING.md#security-issue-notifications) for more information.
-
-Although this repository is released under the  MIT-0 license, its front-end and SQL implementation use the following third party projects:
-- [psycopg2-binary](https://github.com/psycopg/psycopg2)
-- [jackspeak](https://github.com/isaacs/jackspeak)
-- [package-json-from-dist](https://github.com/isaacs/package-json-from-dist)
-- [path-scurry](https://github.com/isaacs/path-scurry)
-
-These projects' licensing includes the LGPL v3 and  BlueOak-1.0.0 licenses.
-
-# Legal Disclaimer
-
-You should consider doing your own independent assessment before using the content in this sample for production purposes. This may include (amongst other things) testing, securing, and optimizing the content provided in this sample, based on your specific quality control practices and standards.
+This project is licensed under the MIT-0 License.

aws-genai-llm-chatbot/README.md

@@ -0,0 +1,122 @@
+# AWS GenAI LLM Chatbot - SeedFarmer Blueprint
+
+This directory contains the SeedFarmer blueprint (also known as a "capability" in Nexus terminology) for deploying the AWS GenAI LLM Chatbot solution.
+
+## What is SeedFarmer?
+
+[SeedFarmer](https://seed-farmer.readthedocs.io/) is a deployment framework designed to simplify the process of deploying complex AWS solutions across multiple accounts and regions. It provides a consistent way to define, deploy, and manage infrastructure using a hierarchical structure of deployments, groups, and modules.
+
+> **Note:** In the Nexus ecosystem, the terms "blueprint" and "capability" are used interchangeably to refer to a SeedFarmer deployment configuration.
+
+## Directory Structure
+
+```
+aws-genai-llm-chatbot/
+├── assets/                      # Visual assets and example configurations
+│   ├── chatbot-icon.svg         # Icon for the catalog listing
+│   ├── chatbot-thumbnail.svg    # Thumbnail for the catalog detail page
+│   └── example-input.yaml       # Example input parameters
+├── modules/                     # SeedFarmer modules
+│   └── chatbot/                 # Main chatbot module
+│       ├── deployspec.yaml      # Deployment instructions
+│       └── module.yaml          # Module definition
+├── package/                     # Package for Nexus integration
+│   └── package/                 # Nested directory required by Nexus
+│       └── capability.yaml      # Copy of capability.yaml for Lambda processing
+├── capability.yaml              # Blueprint definition for Nexus catalog
+├── deployment.yaml              # SeedFarmer deployment manifest
+├── README.md                    # This file
+└── seedfarmer.yaml              # Project metadata
+```
+
+## File Descriptions
+
+### capability.yaml
+
+This file defines the blueprint for the Nexus catalog, including:
+- Metadata: name, description, version
+- Input parameters and their validation rules
+- Deployment environments
+- Labels for categorization
+
+This is the primary file that determines how the solution appears in the Nexus catalog and what configuration options are available to users.
+
+### deployment.yaml
+
+The main SeedFarmer deployment manifest that defines:
+- Deployment structure
+- Target accounts and regions
+- Module groups and their relationships
+- Environment variable mapping
+
+This file serves as the entry point for SeedFarmer when deploying the solution.
+
+### seedfarmer.yaml
+
+Contains project metadata:
+- Project name and description
+- Reference to README.md for documentation
+
+This file provides additional context for the SeedFarmer deployment.
+
+### modules/chatbot/module.yaml
+
+Defines the chatbot module:
+- Parameters passed from environment variables
+- Output definitions for deployed resources
+- Stack naming convention
+
+This file specifies how the CDK stack should be deployed and what outputs should be collected.
+
+### modules/chatbot/deployspec.yaml
+
+Contains deployment instructions:
+- Commands to execute during deployment
+- Environment variable handling
+- CDK deployment configuration
+- Cleanup commands for destruction
+
+This file is executed by SeedFarmer during the deployment process.
+
+### assets/example-input.yaml
+
+Provides an example configuration with:
+- Sample values for all parameters
+- Comments explaining each parameter
+- Default values and recommendations
+
+This file helps users understand how to configure the solution.
+
+### assets/chatbot-icon.svg and assets/chatbot-thumbnail.svg
+
+Visual assets for the Nexus catalog:
+- Icon: Small image for the catalog listing
+- Thumbnail: Larger image for the catalog detail page
+
+These files enhance the visual presentation of the solution in the Nexus catalog.
+
+## Deployment Process
+
+When deployed through SeedFarmer or the Nexus catalog, the process follows these steps:
+
+1. User selects the blueprint from the Nexus catalog
+2. User configures parameters through the Nexus UI
+3. SeedFarmer creates a deployment manifest based on these parameters
+4. SeedFarmer deploys the modules in the specified order
+5. Outputs are collected and made available to the user
+
+## Key Parameters
+
+The blueprint supports several configuration parameters:
+
+- **Core Parameters**: PREFIX, BEDROCK_REGION, TARGET_ACCOUNT
+- **Feature Flags**: BEDROCK_ENABLE, RAG_ENABLE, NEXUS_ENABLE
+- **Security Options**: CREATE_CMKS, RETAIN_ON_DELETE
+- **RAG Options**: RAG_OPENSEARCH_ENABLE
+- **Nexus Integration**: NEXUS_GATEWAY_URL, NEXUS_AUTH_CLIENT_ID, etc.
+
+## Additional Resources
+
+- [SeedFarmer Documentation](https://seed-farmer.readthedocs.io/)
+- [Nexus Blueprint Guide](https://nexus-3p-vending-d523f3.pages.aws.dev/)
+- [AWS GenAI LLM Chatbot Documentation](https://github.com/aws-samples/aws-genai-llm-chatbot)

aws-genai-llm-chatbot/assets/chatbot-icon.svg

@@ -0,0 +1,37 @@
+# AWS GenAI LLM Chatbot Configuration
+# --------------------------------
+# This file contains the configuration parameters for the AWS GenAI LLM Chatbot deployment.
+# Modify the values below to customize your deployment.
+
+# Core parameters
+# ------------------------------
+TARGET_ACCOUNT: 123456789012 # Your AWS Account ID
+PREFIX: chatbot           # Prefix for all resources (max 16 chars)
+BEDROCK_REGION: us-east-1 # AWS region for Amazon Bedrock
+
+DEPLOYMENT_TYPE: default  # Deployment type (default or custom)
+RETAIN_ON_DELETE: false    # Retain resources on delete
+CREATE_CMKS: false         # Create customer managed KMS keys
+
+# Bedrock integration
+# ------------------------------
+BEDROCK_ENABLE: false      # Enable Amazon Bedrock integration
+
+# RAG capabilities
+# ------------------------------
+RAG_ENABLE: false          # Enable RAG capabilities
+# RAG_OPENSEARCH_ENABLE: true # Use OpenSearch as vector store
+# RAG_AURORA_ENABLE: false  # Enable Aurora as RAG engine
+# RAG_KENDRA_ENABLE: false  # Enable Kendra as RAG engine
+# RAG_KENDRA_CREATE_INDEX: false # Create a new Kendra index
+# RAG_KENDRA_ENTERPRISE: false # Use Kendra Enterprise edition
+# RAG_KNOWLEDGE_BASE_ENABLE: false # Enable Knowledge Base as RAG engine
+# RAG_CROSS_ENCODING_ENABLE: false # Enable cross-encoding for RAG
+
+# Nexus integration (if needed)
+# ------------------------------
+NEXUS_ENABLE: false      # Enable Nexus integration
+# NEXUS_GATEWAY_URL: https://your-nexus-gateway.example.com # Nexus Gateway URL
+# NEXUS_AUTH_CLIENT_ID: client-12345    # Nexus Auth Client ID
+# NEXUS_AUTH_CLIENT_SECRET: secret-xyz  # Nexus Auth Client Secret
+# NEXUS_AUTH_TOKEN_URL: https://your-token-url.example.com  # Nexus Auth Token URL