smx-mcp: SMX by Space Markets (testnet) MCP server

MCP server for SMX, the Space Markets testnet venue for humans and agents, and the Space Markets Index (SMI), published by Space Markets, Inc. SMX is operated by SMX Markets Ltd (BVI). Testnet only: Base Sepolia (chain id 84532). Test tokens have no monetary value.

Two separate products, kept separate in every tool:

• SMI (smi_* tools): information on orbital launch activity and other space-sector data. SMI results never contain market prices. Data from GCAT (J. McDowell, planet4589.org/space/gcat), CC BY 4.0, modified by Space Markets. Not affiliated with or endorsed by SpaceX. Data only, not advice.

• SMX event markets (smx_* tools): testnet markets priced in test USDC. Read from the Base Sepolia contracts and the SMX agent API.

This server cannot place, cancel or claim orders and never resolves markets. Orders are signed by your own wallet; smx_trading_guide returns the steps and smx_check_cancel_safety helps you follow the claim-before-cancel rule.

Tools

All tools are annotated readOnlyHint: true and return structuredContent plus a one-line text summary.

Paid tools (x402, testnet USDC, no real value)

Paid tools pay $0.01 in Circle testnet USDC on Base Sepolia via x402 from your own wallet key in X402_PRIVATE_KEY. This package never contains a key. Without the variable, paid tools make no request and explain how to set one up. Before signing, the server checks the 402 challenge: network must be eip155:84532, asset Circle testnet USDC 0x036CbD53842c5426634e7929541eC2318f3dCF7e, receiver 0x5799fe0715C04f479f7f80Fbe6C4CFb384A8E0e9, and amount at most 10000 atomic units ($0.01). Anything else is refused unsigned. Errors (400/404) are not charged.

Use a fresh test wallet (never one with real funds) and get Circle testnet USDC from https://faucet.circle.com (choose Base Sepolia).

Related MCP server: Base Network MCP Server

Install

Requires Node.js 20+. Until the package is published, replace npx -y smx-mcp with node /absolute/path/to/smx-mcp/dist/index.js (after npm ci && npm run build).

Claude Desktop

claude_desktop_config.json (Settings, Developer, Edit Config):

{
  "mcpServers": {
    "smx": {
      "command": "npx",
      "args": ["-y", "smx-mcp"],
      "env": { "X402_PRIVATE_KEY": "0xYOUR_BASE_SEPOLIA_TEST_KEY_optional" }
    }
  }
}

Leave out env to use only the free tools.

Cursor

~/.cursor/mcp.json (global) or .cursor/mcp.json (project):

{
  "mcpServers": {
    "smx": {
      "command": "npx",
      "args": ["-y", "smx-mcp"],
      "env": { "X402_PRIVATE_KEY": "${env:X402_PRIVATE_KEY}" }
    }
  }
}

Any MCP client

• stdio: command npx, args ["-y", "smx-mcp"], optional env X402_PRIVATE_KEY.

• Streamable HTTP: run npx -y smx-mcp --http 8787 and point the client at http://localhost:8787/mcp (stateless, JSON responses). Paid tools are off over HTTP unless SMX_MCP_HTTP_PAID=1 is set, so a hosted server never pays from its own wallet for callers. GET /health for checks.

• Claude Code: claude mcp add smx -- npx -y smx-mcp

• MCP Inspector: npx @modelcontextprotocol/inspector node dist/index.js

Telemetry

Requests to smx.space carry the headers X-SMX-Client (version), X-SMX-Install (a random install id stored in ~/.config/smx-mcp/install-id) and X-SMX-Tool (tool name). They are used only to count anonymous usage. Nothing is sent to any other host. Set SMX_MCP_TELEMETRY=0 to turn off the install id and tool name.

Details: the id file can also live in $XDG_CONFIG_HOME/smx-mcp/ or $SMX_MCP_CONFIG_DIR; delete it to get a new id. Hosted HTTP mode (--http) uses one random id per server process, prefixed hosted-, and a per-process id prefixed ephemeral- is used if the file cannot be written. With SMX_MCP_TELEMETRY=0 only X-SMX-Client is sent. The headers are added only when the request goes to https://smx.space: if SMX_ORIGIN points at another host they are not sent, and redirects are followed hop by hop so a redirect to another host never carries them. On the SMX side these values are logged next to a salted hash of the IP, never the raw IP.

Licence and data

The code is MIT-licensed. The MIT licence covers this code only, not the data it returns. SMI and SMX data come from smx.space under its published terms (SMI: https://smx.space/smi/terms/). GCAT data is CC BY 4.0, modified by Space Markets. Provided as-is, without warranty.

Environment

Develop and test

npm ci
npm run build
npm test              # unit checks, telemetry headers (local echo server), copy-rules check (free live reads, no payments)
npm run smoke         # stdio client: every free tool against live endpoints
npm run smoke:http    # HTTP transport: tools/list + two free calls; asserts paid tools are off
node test/smoke.mjs --paid   # 2 paid calls ($0.02 testnet USDC) + one 404 that must not be charged

The copy check enforces: no old codename, "mock", "odds" or "mainnet" in any description; SMI descriptions avoid settle/settlement/benchmark/live/real-time/reference rate/official/tradeable/signal; SMI outputs carry no price keys and include the publisher and disclaimer; paid tools say "testnet USDC, no real value"; no trading or resolve tools.

Links: https://smx.space/skill.md · https://smx.space/llms.txt · https://smx.space/openapi.yaml · https://smx.space/smi-api/skill.md