ocireg-mcp
An MCP server that provides tools for querying OCI registries and image references.
OCI Registry MCP Server
An MCP (Model Context Protocol) server that provides tools for querying OCI registries and image references.
Overview
This project implements an SSE-based MCP server that allows LLM-powered applications to interact with OCI registries. It provides tools for retrieving information about container images, listing tags, and more.
Features
- Get information about OCI images
- List tags for repositories
- Get image manifests
- Get image configs
MCP Tools
The server provides the following MCP tools:
get_image_info
Get information about an OCI image.
Input:
image_ref: The image reference (e.g., docker.io/library/alpine:latest)
Output:
- Image information including digest, size, architecture, OS, creation date, and number of layers
list_tags
List tags for a repository.
Input:
repository: The repository name (e.g., docker.io/library/alpine)
Output:
- List of tags for the repository
get_image_manifest
Get the manifest for an OCI image.
Input:
image_ref: The image reference (e.g., docker.io/library/alpine:latest)
Output:
- The image manifest
get_image_config
Get the config for an OCI image.
Input:
image_ref: The image reference (e.g., docker.io/library/alpine:latest)
Output:
- The image config
Usage
Running with ToolHive (Recommended)
The easiest way to run the OCI Registry MCP server is using ToolHive, which provides secure, containerized deployment of MCP servers:
# Install ToolHive (if not already installed)
# See: https://docs.stacklok.com/toolhive/guides-cli/install
# Register a supported client so ToolHive can auto-configure your environment
thv client setup
# Run the OCI Registry MCP server (packaged as 'oci-registry' in ToolHive)
thv run oci-registry
# List running servers
thv list
# Get detailed information about the server
thv registry info oci-registry
The server will be available to your MCP-compatible clients and can query OCI registries for image information.
Authentication with ToolHive
If you need to access private registries, you can provide authentication credentials using ToolHive's secret management:
# For bearer token authentication
thv secret set oci-token
# Enter your bearer token when prompted
thv run --secret oci-token,target=OCI_TOKEN oci-registry
# For username/password authentication
thv secret set oci-username
thv secret set oci-password
# Enter your credentials when prompted
thv run --secret oci-username,target=OCI_USERNAME --secret oci-password,target=OCI_PASSWORD oci-registry
Development
Prerequisites
- Go 1.21 or later
- Access to OCI registries
Authentication
The server supports the following authentication methods for accessing private OCI registries:
-
Bearer Token: Set the following environment variable:
OCI_TOKEN: Bearer token for registry authentication
-
Username and Password: Set the following environment variables:
OCI_USERNAME: Username for registry authenticationOCI_PASSWORD: Password for registry authentication
-
Docker Config: If no token or username/password is provided, the server will use the default Docker keychain, which reads credentials from
~/.docker/config.json.
Examples:
# Bearer token authentication
export OCI_TOKEN=mytoken
# Username/password authentication
export OCI_USERNAME=myuser
export OCI_PASSWORD=mypassword
Port Configuration
The server can be configured to listen on a specific port using either:
-
Environment Variable:
MCP_PORT: The port number to listen on (must be between 0 and 65535)- If not set or invalid, defaults to port 8080
-
Command-line Flag:
-port: Overrides the environment variable setting (must be between 0 and 65535)- If invalid port provided it defaults to port 8080
- Example:
./ocireg-mcp -port 9090
Testing
go test ./...
Linting
golangci-lint run
Contributing
We welcome contributions to this MCP server! If you'd like to contribute, please review the for details on how to get started.
If you run into a bug or have a feature request, please
open an issue in the
repository or join us in the #mcp-servers channel on our
community Discord server.
License
This project is licensed under the Apache v2 License - see the LICENSE file for details.
