#25884 aws_role_name in proxy config YAML silently dropped — cross-account Bedrock AssumeRole never fires
# Bug Report: `aws_role_name` in proxy config YAML silently ignored — cross-account Bedrock AssumeRole never fires
## Summary
When configuring `aws_role_name` in `litellm_params` via the proxy config YAML for cross-account Bedrock access, the parameter is silently dropped during optional params processing. The STS AssumeRole call never fires, and Bedrock calls land in the host account's IAM identity instead of the target role's account.
## Use Case
We're a government organization (City and County of San Francisco) deploying LiteLLM as a centralized LLM Gateway on ECS Fargate. We have a central platform account running LiteLLM and multiple department accounts with Bedrock model access enabled. Each department has its own AWS account with a `LiteLLMBedrockAccess` IAM role that the LiteLLM ECS task role can assume.
Our config uses tag-based routing so each department's models route to their own Bedrock account for billing isolation:
```yaml model_list: - model_name: claude-sonnet-4-6 litellm_params: model: bedrock/us.anthropic.claude-sonnet-4-6 aws_region_name: us-west-2 aws_role_name: arn:aws:iam::244910800867:role/LiteLLMBedrockAccess aws_session_…