IO Aerospace MCP Server

Use the hosted server now, or self-host fast with Docker or .NET. Minimal steps below.

Hosted (no setup) - Streamable-HTTP

Base URL (streamable-HTTP, recommended): https://mcp.io-aerospace.org
SSE endpoint (legacy): /sse - Only for backward compatibility
Modern MCP clients (2024+) automatically use streamable-HTTP with the base URL.
Only use /sse if you have an older client that specifically requires SSE protocol.

MCP client (Claude Desktop, HTTP - Streamable-HTTP)

{
  "mcpServers": {
    "astrodynamics": {
      "transport": { "type": "http", "url": "https://mcp.io-aerospace.org" }
    }
  }
}

Uses modern streamable-HTTP transport. Do NOT append /sse.

MCP client (STDIO)

Download the Server.Stdio executable for your OS (see “Download executables”).
Provide kernels via -k or IO_DATA_DIR.

{
  "mcpServers": {
    "astrodynamics": {
      "command": "/path/to/Server.Stdio",
      "args": ["-k", "/path/to/kernels"]
    }
  }
}

# Run directly
./Server.Stdio -k /path/to/kernels
# Windows
Server.Stdio.exe -k C:\path\to\kernels

Download executables

Releases: GitHub Releases → download single-file Server.Stdio for your OS (linux-x64, win-x64, osx-arm64).
Actions (artifacts): Release single-file (server.Stdio) → latest run → Artifacts → pick your OS.
Linux/macOS: chmod +x ./Server.Stdio
macOS (if blocked): xattr -d com.apple.quarantine ./Server.Stdio

Self-host quick

Docker (dev):

git clone https://github.com/IO-Aerospace-software-engineering/mcp-server
cd mcp-server
docker-compose up

HTTP: http://localhost:8080

.NET:

git clone https://github.com/IO-Aerospace-software-engineering/mcp-server
cd mcp-server
dotnet build
# STDIO (MCP clients)
./Server.Stdio -k /path/to/kernels
# or via env
export IO_DATA_DIR="/path/to/kernels" && ./Server.Stdio
# HTTP (web - supports streamable-HTTP + legacy SSE)
cd Server.Http && dotnet run  # http://localhost:8080

Kernels (minimal set)

de440s.bsp (ephemeris)
latest_leapseconds.tls
pck00011.tpc
earth_latest_high_prec.bpc

Troubleshooting

Missing kernels dir: fix -k or IO_DATA_DIR path.
Kernel load failed: ensure files exist and are readable.
HTTP errors: check ports/firewall/proxy.

Legacy SSE (old clients only)

Only use this if you have an older client that requires SSE protocol:

// ONLY for legacy SSE clients
const eventSource = new EventSource('https://mcp.io-aerospace.org/sse');
eventSource.onmessage = (event) => console.log('message', event.data);
eventSource.onerror = (err) => console.error('sse error', err);