awsapimcproxy

awsapimcproxy

A multi-profile proxy for the AWS API MCP Server.

The AWS API MCP server picks its AWS identity from the environment (AWS_API_MCP_PROFILE_NAME) at launch, so a single server can only use one profile. awsapimcproxy runs one upstream server per profile, mirrors all of their tools, and adds a profile argument to each tool. When a tool is called, the proxy picks the matching profile's process and forwards the request.

Claude Code ──stdio──▶ awsapimcproxy ──┬─ profile=dev  ─▶ aws-api-mcp-server (AWS_API_MCP_PROFILE_NAME=my-dev)
                                       └─ profile=prod ─▶ aws-api-mcp-server (AWS_API_MCP_PROFILE_NAME=my-prod)

Requirements

The upstream server is launched on demand. By default that is uvx awslabs.aws-api-mcp-server@latest, so uv must be installed (override with command in the config).

Install

go install github.com/winebarrel/awsapimcproxy/cmd/awsapimcproxy@latest

Configuration

Create a YAML config file. Values are passed through os.ExpandEnv, so values can be referenced as ${ENV_VAR} instead of being written literally.

# awsapimcproxy.yml

# Optional. Default: [uvx, awslabs.aws-api-mcp-server@latest]
# command: [uvx, awslabs.aws-api-mcp-server@latest]

profiles:
  - name: dev
    aws_profile: my-dev
    region: us-east-1
  - name: prod
    aws_profile: my-prod
    region: ap-northeast-1

Each profile launches its own upstream process:

• aws_profile is passed as AWS_API_MCP_PROFILE_NAME.
• region is passed as AWS_REGION.
• env adds or overrides any other environment variables for that process.

Usage

Usage: awsapimcproxy --config=STRING [flags]

Flags:
  -h, --help             Show help.
  -c, --config=STRING    Config file path ($AWSAPIMCPROXY_CONFIG).
      --version

Claude Code

Register it as an MCP server:

{
  "mcpServers": {
    "awsapimcproxy": {
      "command": "awsapimcproxy",
      "args": ["--config", "/path/to/awsapimcproxy.yml"]
    }
  }
}

How it works

• On startup the proxy launches the upstream server for the first profile and lists its tools.
• Each upstream tool is re-registered with a required profile string argument (enumerated over the configured profile names). A proxy-native list_profiles tool is also added.
• On a tool call, the proxy strips the profile argument, looks up that profile's upstream process (launching it lazily, then caching it), and forwards the call.