> ## Documentation Index
> Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AWS Signature Version 4

> The gateway signs each request to an MCP server on AWS with AWS Signature Version 4.

For an MCP server on AWS, such as one hosted on Amazon Bedrock AgentCore, the gateway signs each request with [AWS Signature Version 4](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_sigv.html). Signing applies to MCP servers, not to [APIs added as tools](https://developers.telnyx.com/docs/agent-gateway/targets/tools.md#apis).

## Settings

The server's `auth` names the region, and optionally the service and credentials:

```json theme={null}
{
  "type": "aws_sigv4",
  "region": "us-east-1",
  "access_key_id": "AKIAIOSFODNN7EXAMPLE",
  "secret_access_key": "example-secret-access-key"
}
```

* `region` is the AWS region to sign for.
* `service` is the service to sign for, `bedrock-agentcore` unless set.
* `access_key_id` and `secret_access_key`, with an optional `session_token`, are AWS keys. `role_name` is the ARN of a role for the gateway to assume instead.