Principle:Cohere ai Cohere python Bedrock Client Initialization
| Property | Value |
|---|---|
| Type | Principle |
| Domain | Client Initialization, AWS Bedrock, Transparent Proxy |
| Source | Cohere Python SDK |
| Last Updated | 2026-02-15 |
| Implemented By | Implementation:Cohere_ai_Cohere_python_BedrockClientV2_Init |
Overview
A client initialization pattern for accessing Cohere models deployed on AWS Bedrock with transparent authentication and response transformation.
Description
Bedrock Client Initialization creates a specialized Cohere client that routes all API calls through AWS Bedrock instead of the direct Cohere API. BedrockClientV2 extends AwsClientV2 which extends ClientV2, inheriting all standard SDK methods (chat, embed, rerank). The key difference is that it creates an httpx.Client with event hooks for SigV4 signing (request hook) and Bedrock response format conversion (response hook). This makes Bedrock deployment transparent — the same code works with both direct API and Bedrock.
Usage
Use BedrockClientV2 when accessing Cohere models through AWS Bedrock. Provide AWS credentials and region. All standard SDK methods work transparently. Use Bedrock model identifiers (e.g., "cohere.command-r-plus-v1:0").
- Initialize with AWS credentials or rely on default credential chain
- Use Bedrock-specific model identifiers
- All standard SDK methods (chat, embed, rerank) work without modification
- Response types are identical to the direct Cohere API
Theoretical Basis
The transparent proxy pattern enables code portability between deployment targets. By intercepting at the HTTP event hook level, the SDK can rewrite URLs, transform payloads, and sign requests without modifying the high-level API surface.
- Inheritance chain (BedrockClientV2 -> AwsClientV2 -> ClientV2) preserves the full API surface
- Event hooks provide a clean separation between transport concerns and business logic
- The pattern enables switching between Cohere direct API, Bedrock, and SageMaker with minimal code changes