A Model Context Protocol (MCP) server for NATS messaging system integration

Developer Sinadarbouy released mcp-nats, a Model Context Protocol (MCP) server that connects AI models and applications to NATS messaging systems through a standardized interface, certified by MCP Review. The Go 1.25-based server exposes tools for read-only NATS server and stream inspection, object store and key-value operations, message publishing, and multi-account support, and is compatible with MCP clients such as Claude Desktop. Tagged releases publish the ghcr.io/sinadarbouy/mcp-nats container image and sign the multi-arch index with Sigstore Cosign via keyless GitHub OIDC, with Helm chart version 0.1.4 installable from OCI.

A Model Context Protocol MCP https://modelcontextprotocol.io/ server for NATS https://nats.io/ messaging system integration This MCP server is certified by MCP Review https://mcpreview.com/mcp-servers/sinadarbouy/mcp-nats . This project provides a Model Context Protocol MCP server for NATS, enabling AI models and applications to interact with NATS messaging systems through a standardized interface. It exposes a comprehensive set of tools for interacting with NATS servers, making it ideal for AI-powered applications that need to work with messaging systems. The Model Context Protocol MCP is an open protocol that standardizes how applications provide context to Large Language Models LLMs . This server implements the MCP specification to provide NATS messaging capabilities to LLMs and AI applications, allowing them to: - Interact with NATS messaging systems in a standardized way - Safely inspect and monitor NATS servers and streams - Perform read-only operations through a secure interface - Integrate with other MCP-compatible clients and hosts - Server Management Read-only Operations - List and inspect NATS servers - Server health monitoring and ping - Server information retrieval - Round-trip time RTT measurement - Stream Operations Read-only Operations - View and inspect NATS streams - Stream state and information queries - Message viewing and retrieval - Subject inspection - Object Store Operations - Create and manage object store buckets - Put and get files from object stores - List buckets and their contents - Delete objects and buckets - Watch buckets for changes - Seal buckets to prevent updates - Key-Value Operations - Create and manage KV buckets - Store and retrieve key-value pairs - Watch for KV updates - Delete keys and buckets - Publish Operations - Publish messages to NATS subjects - Support for different message formats - Asynchronous message publishing - Account Operations - View account information and metrics - Generate account reports connections and statistics - Create and restore account backups - Inspect TLS chain for connected servers - Multi-Account Support - Handle multiple NATS accounts simultaneously - Secure credential management - MCP Integration - Implements MCP server specification - Compatible with MCP clients like Claude Desktop - Standardized tool definitions for LLM interaction - Safe, read-only operations for AI interaction with NATS - Go 1.25 or later - NATS server accessible via URL - NATS credentials for authentication - MCP-compatible client e.g., Claude Desktop, or other MCP clients go install github.com/sinadarbouy/mcp-nats/cmd/mcp-nats@latest git clone https://github.com/sinadarbouy/mcp-nats.git cd mcp-nats go build -o mcp-nats ./cmd/mcp-nats The chart is in deploy/charts/mcp-nats https://github.com/sinadarbouy/mcp-nats/blob/main/deploy/charts/mcp-nats . Install guides including OCI / GHCR and umbrella-chart dependencies , values overview, probes, and the HashiCorp Vault Agent Injector example are in deploy/charts/mcp-nats/README.md https://github.com/sinadarbouy/mcp-nats/blob/main/deploy/charts/mcp-nats/README.md . Quick start from the repository root: helm install mcp-nats ./deploy/charts/mcp-nats --namespace mcp-nats --create-namespace Published releases are also installable from OCI, for example: helm install mcp-nats oci://ghcr.io/sinadarbouy/charts/mcp-nats --version "0.1.4" --namespace mcp-nats --create-namespace See the chart README for Chart.yaml dependency snippets and registry login. Tagged releases push ghcr.io/sinadarbouy/mcp-nats and sign the multi-arch index and each platform manifest with Sigstore Cosign https://docs.sigstore.dev/cosign/signing/overview/ using keyless GitHub OIDC. Verify a published tag: cosign verify ghcr.io/sinadarbouy/mcp-nats:0.1.4 \ --certificate-identity-regexp 'https://github.com/sinadarbouy/mcp-nats/.github/workflows/ release\.yml@refs/tags/v. |sign-image\.yml@refs/heads/main ' \ --certificate-oidc-issuer https://token.actions.githubusercontent.com Historical tags published before signing was added can be signed from Actions → sign-image run from main . Use Tilt to deploy both official NATS and the local mcp-nats chart for end-to-end auth testing. Prerequisites: - Tilt installed - Helm installed - Docker Desktop Kubernetes enabled - Current kube context set to docker-desktop Start the integration stack: tilt up This uses: - Tiltfile - deploy/tilt/nats-values.yaml - deploy/tilt/mcp-nats-values.yaml - a local image build with deploy/tilt/Dockerfile.tilt before Helm deploy Stop and clean up: tilt down helm uninstall -n mcp-nats-tilt nats mcp-nats kubectl delete namespace mcp-nats-tilt --ignore-not-found Quick verification commands: kubectl get pods,svc -n mcp-nats-tilt kubectl logs -n mcp-nats-tilt deploy/mcp-nats-mcp-nats kubectl logs -n mcp-nats-tilt statefulset/nats kubectl port-forward -n mcp-nats-tilt svc/mcp-nats-mcp-nats 8000:8000 Auth smoke test: - NATS is configured with mcpuser / mcppassword in deploy/tilt/nats-values.yaml . - mcp-nats uses the same credentials via chart-managed secret in deploy/tilt/mcp-nats-values.yaml . - If credentials mismatch, mcp-nats logs will show connection/authentication failures. - NATS URL : The URL of your NATS server e.g., localhost:4222 - NATS <ACCOUNT CREDS : Base64 encoded NATS credentials for each account - Example: NATS SYS CREDS , NATS A CREDS - Example: - NATS NO AUTHENTICATION : Set to "true" to enable anonymous connections no credentials required - NATS USER : Username or token for user/password authentication - NATS PASSWORD : Password for user/password authentication - --transport : Transport type stdio, sse, or streamable-http , default: streamable-http - --address : Address for HTTP transport to listen on, default: 0.0.0.0:8000 - --endpoint-path : Endpoint path for streamable-http transport, default: /mcp - --sse-address : Deprecated alias of --address - --log-level : Log level debug, info, warn, error , default: info - --json-logs : Output logs in JSON format, default: false - --no-authentication : Allow anonymous connections without credentials - --user : NATS username or token can also be set via NATS USER env var - --password : NATS password can also be set via NATS PASSWORD env var - GET /livez : process liveness check does not validate NATS dependency - GET /readyz : readiness check validates TCP connectivity to NATS URL - GET /healthz : compatibility alias for liveness These endpoints are available when running with sse or streamable-http transport. Default probes and lifecycle.preStop are documented in deploy/charts/mcp-nats/README.md https://github.com/sinadarbouy/mcp-nats/blob/main/deploy/charts/mcp-nats/README.md . The MCP NATS server supports three authentication methods: 1. Credentials-based Authentication default : Uses NATS credentials files - Set NATS <ACCOUNT CREDS environment variables - Requires account name parameter in all tools 2. Set 3. User/Password Authentication : Uses username and password - Set NATS USER and NATS PASSWORD environment variables or use --user and --password flags 4. Set 5. Anonymous Authentication : No authentication required - Set NATS NO AUTHENTICATION=true environment variable or use --no-authentication flag 6. Set Run with Streamable HTTP transport default and debug logging ./mcp-nats --log-level debug Run with custom Streamable HTTP endpoint path ./mcp-nats --transport streamable-http --address localhost:9000 --endpoint-path /mcp Run with JSON logging ./mcp-nats --json-logs Run with SSE transport ./mcp-nats --transport sse --address localhost:9000 Run with anonymous authentication ./mcp-nats --no-authentication Run with user/password authentication ./mcp-nats --user myuser --password mypass Run with environment variables for authentication NATS NO AUTHENTICATION=true ./mcp-nats NATS USER=myuser NATS PASSWORD=mypass ./mcp-nats Make sure your .vscode/settings.json includes: "mcp": { "servers": { "nats": { "type": "streamable-http", "url": "http://localhost:8000/mcp" } } } Cursor mcpServers : { "mcpServers": { "nats": { "env": { "NATS URL": "nats://localhost:4222", "NATS SYS CREDS": "<base64 of SYS account creds ", "NATS A CREDS": "<base64 of A account creds " }, "url": "http://localhost:8000/mcp" } } } Anonymous Authentication: { "mcpServers": { "nats": { "env": { "NATS URL": "nats://localhost:4222", "NATS NO AUTHENTICATION": "true" }, "url": "http://localhost:8000/mcp" } } } User/Password Authentication: { "mcpServers": { "nats": { "env": { "NATS URL": "nats://localhost:4222", "NATS USER": "myuser", "NATS PASSWORD": "mypass" }, "url": "http://localhost:8000/mcp" } } } If using the binary: { "mcpServers": { "nats": { "command": "mcp-nats", "args": "--transport", "stdio" , "env": { "NATS URL": "nats://localhost:4222", "NATS SYS CREDS": "<base64 of SYS account creds ", "NATS A CREDS": "<base64 of A account creds " } } } } Anonymous Authentication with Binary: { "mcpServers": { "nats": { "command": "mcp-nats", "args": "--transport", "stdio", "--no-authentication" , "env": { "NATS URL": "nats://localhost:4222" } } } } User/Password Authentication with Binary: { "mcpServers": { "nats": { "command": "mcp-nats", "args": "--transport", "stdio", "--user", "myuser" , "env": { "NATS URL": "nats://localhost:4222", "NATS PASSWORD": "mypass" } } } } Docker Configuration: { "mcpServers": { "nats": { "command": "docker", "args": "run", "-i", "--rm", "--init", "-e", "NATS URL", "-e", "NATS SYS CREDS", "ghcr.io/sinadarbouy/mcp-nats:0.1.4", "--transport", "stdio" , "env": { "NATS SYS CREDS": "<base64 of SYS account creds ", "NATS URL": "<nats url " } } } } - Go 1.25+ - Docker optional - NATS CLI - Understanding of MCP specification make help Print help message make build Build the binary make run Run in stdio mode make run-sse Run with SSE transport make lint Run linters For detailed instructions on how to test the MCP server using stdio transport, please refer to our Stdio Example Guide https://github.com/sinadarbouy/mcp-nats/blob/main/docs/stdio/stdio example.md .