MCP Helm Server

An MCP (Model Context Protocol) server that provides tools for interacting with Helm repositories and charts. This

server enables AI assistants to query Helm repositories, retrieve chart information, and access chart values without

requiring local Helm installation.

The purpose of using MCP for Helm is to avoid making up format of `values.yaml` and contents of the charts when working

with LLMs.

Instead, the server provides a standardized way to access this information, making it easier for AI assistants to

interact with Helm charts and repositories.

This MCP server is and will be providing tools for working with Helm repositories only. If you need to work with other

Kubernetes resources, consider using a separate MCP server that provides tools for Kubernetes resources.

Features

The MCP Helm server provides the following tools:

• list_repository_charts - Lists all charts available in a Helm repository (or chart name for OCI registries)
• list_chart_versions - Lists all available versions/tags for a chart
• get_latest_version_of_chart - Retrieves the latest version of a specific chart
• get_chart_values - Retrieves the values file for a chart (latest version or specific version)
• get_chart_contents - Retrieves the contents of a chart (including templates, values, and metadata)
• get_chart_dependencies - Retrieves the dependencies of a chart as defined in its `Chart.yaml` file
• get_chart_images - Extracts container images used in a Helm chart by rendering templates and parsing Kubernetes

manifests

Repository Types

All tools support both traditional HTTP Helm repositories and OCI registries:

OCI Registry Support

OCI (Open Container Initiative) registries store Helm charts as OCI artifacts. Unlike HTTP repositories where multiple

charts share an index, OCI registries typically contain one chart per repository with multiple version tags.

Example usage with OCI:

repository_url: oci://ghcr.io/nginxinc/charts/nginx-ingress
chart_name: (empty - chart name is in the URL)

Try without installation

There is a publicly available instance of the MCP Helm server that you can use to test the features without installing

it: https://mcp-helm.zekker.dev/mcp

Installation

Run with docker

You can run the MCP Helm server using Docker. This is the easiest way to get started without needing to install Go or

build from source.

docker run -d --name mcp-helm -p 8012:8012 ghcr.io/zekker6/mcp-helm:v1.3.0 -mode=sse

Note that the `--mode=sse` flag is used to enable Server-Sent Events mode, which used by MCP clients to connect.

Alternatively, you can use `-mode=http` to enable Streamable HTTP mode.

Via pre-build binary

Download binary from the releases page.

Example for Linux x86_64 (note that other architectures and platforms are also available):

latest=$(curl -s https://api.github.com/repos/zekker6/mcp-helm/releases/latest | grep 'tag_name' | cut -d\" -f4)
wget https://github.com/zekker6/mcp-helm/releases/download/$latest/mcp-helm_Linux_x86_64.tar.gz
tar axvf mcp-helm_Linux_x86_64.tar.gz

Via Mise

Mise (mise-en-place) is a development environment setup tool.

mise i ubi:zekker6/mcp-helm@latest

Install with Go

> Note: Go 1.24.3 is required.

go install github.com/zekker6/mcp-helm/cmd/mcp-helm@latest

Build from Source

> Note: Go 1.24.3 is required.

1. Clone the repository:

git clone https://github.com/zekker6/mcp-helm.git
   cd mcp-helm

2. Build the binary:

go build -o mcp-helm ./cmd/mcp-helm

3. Run the server:

./mcp-helm

Configuration

Configure your MCP client to connect to this server. The server implements the standard MCP protocol for tool discovery

and execution.

Authentication

The server supports authentication for both OCI registries and HTTP Helm repositories.

Command-Line Flags

Basic Authentication

For repositories requiring username/password authentication:

# Create a password file (recommended for security)
echo "your-password" > /path/to/password.txt
chmod 600 /path/to/password.txt

# Run with basic auth
./mcp-helm -username myuser -password-file /path/to/password.txt

OCI Registry Authentication

For private OCI registries, authentication can be configured via:

1. Docker credentials - The server automatically uses credentials from `~/.docker/config.json`

2. Explicit credentials file - Use `-registry-credentials` flag

# Using Docker login (credentials stored in ~/.docker/config.json)
docker login ghcr.io
echo $GITHUB_TOKEN | docker login ghcr.io -u USERNAME --password-stdin

# Using explicit credentials file
./mcp-helm -registry-credentials /path/to/docker/config.json

# Using basic auth for OCI registry
./mcp-helm -username myuser -password-file /path/to/password.txt

Combining basic auth with a registry credentials file

A single instance can serve private HTTP repositories and private OCI registries

at the same time. When both `-username/-password-file` and `-registry-credentials`

are set, OCI requests are routed per registry host:

• If the credentials file resolves a credential for the chart's registry host,

that per-host credential is used (`auths`, `credHelpers`, and `credsStore` are

all consulted, using the same Docker credential resolution as the Helm CLI, so

Docker Hub's canonical `https://index.docker.io/v1/` key is matched correctly).

• Otherwise, the static `-username/-password-file` basic auth is used.

This lets `-registry-credentials` stay authoritative for the OCI registries it

covers while basic auth still applies to HTTP repositories (and any OCI registry

the credentials file does not resolve).

# HTTP repos use basic auth; OCI hosts in config.json use their per-host creds
./mcp-helm \
  -username myuser -password-file /path/to/password.txt \
  -registry-credentials /path/to/docker/config.json

Credentials behind an external credential store (`credsStore`) or per-registry

helper (`credHelpers`) are resolved by invoking that helper binary at runtime.

If the helper is not available in the runtime environment, the affected

registries fall back to basic auth; a warning is logged at startup so this is

visible. Routing considers only the file passed to `-registry-credentials` (no

implicit `~/.docker/config.json` fallback), so list every private OCI registry

you need in that file.

TLS/mTLS Configuration

For repositories with custom TLS requirements:

# Custom CA certificate (for self-signed or internal CAs)
./mcp-helm -tls-ca /path/to/ca.crt

# Client certificate authentication (mTLS)
./mcp-helm -tls-cert /path/to/client.crt -tls-key /path/to/client.key

# Combined: mTLS with custom CA
./mcp-helm -tls-cert client.crt -tls-key client.key -tls-ca ca.crt

# Skip TLS verification (development only, not recommended for production)
./mcp-helm -tls-insecure-skip-verify

Docker Configuration

Example with Docker, passing authentication:

# With basic auth
docker run -d --name mcp-helm -p 8012:8012 \
  -v /path/to/password.txt:/secrets/password.txt:ro \
  ghcr.io/zekker6/mcp-helm:v1.3.0 \
  -mode=sse -username myuser -password-file /secrets/password.txt

# With Docker credentials
docker run -d --name mcp-helm -p 8012:8012 \
  -v ~/.docker/config.json:/root/.docker/config.json:ro \
  ghcr.io/zekker6/mcp-helm:v1.3.0 \
  -mode=sse

Roadmap

• [x] Add more tools
• [x] Support OCI registries
• [x] Support using private HTTP repositories