Gdex MCP

GDEX MCP Server

An MCP (Model Context Protocol) server exposing the GDEX (Geoscience Data Exchange) REST API as tools for LLM clients — dataset discovery/metadata, file listings, data access links, ARCO variables, portal/dataset metrics, staff contacts, and authenticated subsetting-request workflows.

Running locally

pip install -e .

gdex-mcp

Then point your MCP client (Claude Desktop, Claude Code, etc.) at the gdex-mcp command. Configuration is via environment variables or a .env file — see CLAUDE.md's Configuration section. Most tools need no configuration at all; set GDEX_TOKEN only if you'll use the subsetting-request tools (list_request_statuses, check_request_status, get_request_files, submit_subset_request, submit_and_wait_for_request, purge_request).

Running as a shared service

Set GDEX_MCP_TRANSPORT=streamable-http (see Dockerfile) to run this as a network-reachable service instead of a local stdio subprocess. In that mode, callers using the subsetting-request tools pass their own GDEX token as an Authorization: Token header on each request rather than relying on a shared GDEX_TOKEN — see CLAUDE.md's "Two transports" section for how that's wired.

Docker

# Build the image

docker build -t gdex-mcp .

Run the container

docker run -d --name gdex-mcp -p 8080:8080 gdex-mcp

MCP requests go to http://localhost:8080/mcp.

# Stop and remove the container

docker stop gdex-mcp && docker rm gdex-mcp

Deployment

A merged PR to main triggers the GitHub Actions workflow, which runs the test suite (pip install -e ".[test]" && pytest) and then builds a new Docker image and pushes it to Harbor (hub.k8s.ucar.edu/gdex_mcp/gdex-mcp). The app is deployed to Kubernetes via the Helm chart in app-chart/ — see CLAUDE.md's Deployment section for how this follows gdex-web-services' conventions.

# Deploy with Helm

helm upgrade --install gdex-mcp ./app-chart -n

Deploy a test instance

helm upgrade --install gdex-mcp ./app-chart -n --set testName=

MCP Registry

gdex-mcp is published to the official MCP Registry as io.github.rpconroy/gdex-mcp (see server.json), not io.github.NCAR/gdex-mcp. Publishing under the NCAR org namespace kept failing with a 403 even after making org membership public — a known, unresolved issue with the registry's org-membership check (see modelcontextprotocol/registry#1537 and #1649), suspected to be an org-admin-side GitHub OAuth App access restriction rather than anything on our end. .github/workflows/publish-mcp-registry.yaml publishes new versions on v* tags; it uses PAT auth (MCP_GITHUB_TOKEN secret) instead of GitHub OIDC because this repo is NCAR-owned, so Actions OIDC always asserts repository_owner: NCAR and can't authenticate as the personal rpconroy namespace. Once NCAR org access is sorted out, moving to io.github.NCAR/gdex-mcp means publishing a new registry entry (the registry has no rename support) and switching the workflow back to login github-oidc.

Documentation

CLAUDE.md has the full picture: architecture, conventions to follow when adding tools, the two transport modes, and deployment. Read it before making changes here.