AWS Bedrock Knowledge Base Retrieval MCP server

The Amazon Bedrock Knowledge Base Retrieval MCP Server allows you to access and query your Amazon Bedrock Knowledge Bases using natural language, discover knowledge bases and their data sources, filter results, and improve relevance through reranking capabilities.

Prerequisites

Installation Requirements

1. Install uv from Astral
2. Install Python using uv python install 3.10

AWS Requirements

1. AWS CLI Configuration: Configure AWS CLI with credentials and an AWS_PROFILE that has access to Amazon Bedrock and Knowledge Bases
2. Amazon Bedrock Knowledge Base: Have at least one Amazon Bedrock Knowledge Base with the tag key mcp-multirag-kb with a value of true
3. IAM Permissions: Your IAM role/user must have permissions to:
   • List and describe knowledge bases
   • Access data sources
   • Query knowledge bases

Reranking Requirements

For reranking functionality, you need:

1. IAM permissions for both bedrock:Rerank and bedrock:InvokeModel actions
2. These same permissions for the Amazon Bedrock Knowledge Bases service role
3. A supported region for reranking (check the official documentation)
4. Model access for available reranking models in your region

Controlling Reranking

Control reranking with the BEDROCK_KB_RERANKING_ENABLED environment variable:

• false (default): Disables reranking unless explicitly enabled
• true: Enables reranking unless explicitly disabled

Accepted formats:

• Enable: 'true', '1', 'yes', or 'on' (case-insensitive)
• Disable: any other value or not set

For detailed knowledge base setup instructions, see:

• Create a knowledge base
• Managing permissions for Amazon Bedrock knowledge bases
• Permissions for reranking in Amazon Bedrock

Installation

Standard Installation

Configure the MCP server in your MCP client configuration (e.g., for Amazon Q Developer CLI, edit ~/.aws/amazonq/mcp.json):

{
  "mcpServers": {
    "awslabs.bedrock-kb-retrieval-mcp-server": {
      "command": "uvx",
      "args": ["awslabs.bedrock-kb-retrieval-mcp-server@latest"],
      "env": {
        "AWS_PROFILE": "your-profile-name",
        "AWS_REGION": "us-east-1",
        "FASTMCP_LOG_LEVEL": "ERROR",
        "KB_INCLUSION_TAG_KEY": "optional-tag-key-to-filter-kbs",
        "BEDROCK_KB_RERANKING_ENABLED": "false"
      },
      "disabled": false,
      "autoApprove": []
    }
  }
}

Windows Installation

For Windows users, use this configuration format:

{
  "mcpServers": {
    "awslabs.bedrock-kb-retrieval-mcp-server": {
      "disabled": false,
      "timeout": 60,
      "type": "stdio",
      "command": "uv",
      "args": [
        "tool",
        "run",
        "--from",
        "awslabs.bedrock-kb-retrieval-mcp-server@latest",
        "awslabs.bedrock-kb-retrieval-mcp-server.exe"
      ],
      "env": {
        "FASTMCP_LOG_LEVEL": "ERROR",
        "AWS_PROFILE": "your-aws-profile",
        "AWS_REGION": "us-east-1"
      }
    }
  }
}

Docker Installation

First, build the Docker image:

docker build -t awslabs/bedrock-kb-retrieval-mcp-server .

Create a .env file with your AWS credentials:

AWS_ACCESS_KEY_ID=ASIAIOSFODNN7EXAMPLE
AWS_SECRET_ACCESS_KEY=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
AWS_SESSION_TOKEN=AQoEXAMPLEH4aoAH0gNCAPy...truncated...zrkuWJOgQs8IZZaIv2BXIa2R4Olgk

Then configure the MCP server:

{
  "mcpServers": {
    "awslabs.bedrock-kb-retrieval-mcp-server": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "--interactive",
        "--env",
        "FASTMCP_LOG_LEVEL=ERROR",
        "--env",
        "KB_INCLUSION_TAG_KEY=optional-tag-key-to-filter-kbs",
        "--env",
        "BEDROCK_KB_RERANKING_ENABLED=false",
        "--env",
        "AWS_REGION=us-east-1",
        "--env-file",
        "/full/path/to/file/above/.env",
        "awslabs/bedrock-kb-retrieval-mcp-server:latest"
      ],
      "env": {},
      "disabled": false,
      "autoApprove": []
    }
  }
}

Note: Your credentials will need to be kept refreshed from your host.

Limitations

• Results with IMAGE content type are not included in the KB query response.
• The reranking parameter requires additional permissions, Amazon Bedrock model access, and is only available in specific regions.

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "awslabs-bedrock-kb-retrieval-mcp-server" '{"command":"uvx","args":["awslabs.bedrock-kb-retrieval-mcp-server@latest"],"env":{"AWS_PROFILE":"your-profile-name","AWS_REGION":"us-east-1","FASTMCP_LOG_LEVEL":"ERROR","KB_INCLUSION_TAG_KEY":"optional-tag-key-to-filter-kbs","BEDROCK_KB_RERANKING_ENABLED":"false"},"disabled":false,"autoApprove":[]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "awslabs.bedrock-kb-retrieval-mcp-server": {
            "command": "uvx",
            "args": [
                "awslabs.bedrock-kb-retrieval-mcp-server@latest"
            ],
            "env": {
                "AWS_PROFILE": "your-profile-name",
                "AWS_REGION": "us-east-1",
                "FASTMCP_LOG_LEVEL": "ERROR",
                "KB_INCLUSION_TAG_KEY": "optional-tag-key-to-filter-kbs",
                "BEDROCK_KB_RERANKING_ENABLED": "false"
            },
            "disabled": false,
            "autoApprove": []
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "awslabs.bedrock-kb-retrieval-mcp-server": {
            "command": "uvx",
            "args": [
                "awslabs.bedrock-kb-retrieval-mcp-server@latest"
            ],
            "env": {
                "AWS_PROFILE": "your-profile-name",
                "AWS_REGION": "us-east-1",
                "FASTMCP_LOG_LEVEL": "ERROR",
                "KB_INCLUSION_TAG_KEY": "optional-tag-key-to-filter-kbs",
                "BEDROCK_KB_RERANKING_ENABLED": "false"
            },
            "disabled": false,
            "autoApprove": []
        }
    }
}

3. Restart Claude Desktop for the changes to take effect