SnapEX Pay

SnapEX Pay MCP server

MCP server for crypto payments: an AI agent opens its own merchant account and accepts, sends and exchanges crypto.

SnapEX Pay MCP server lets an AI agent work with crypto payments without a person in the loop. The agent connects to https://pay.snapex.pro/mcp, opens a SnapEX Pay merchant account by itself (no captcha, no email) and gets an API key. Then it can create invoices with hosted payment pages, receive crypto on permanent deposit addresses, keep a USDT balance, send payouts in many coins and networks, and manage webhooks. Test mode runs the whole flow without real money. Payouts always start with a free preview and use an idempotency key, so a retry never pays twice. Remote server (Streamable HTTP) or local package: npx -y snapex-pay-mcp.

• Remote server (recommended, nothing to install): https://pay.snapex.pro/mcp — Streamable HTTP.
• Local stdio package: npx -y snapex-pay-mcp — the same tools, a thin client of the same API.
• Docker: docker build -t snapex-pay-mcp . && docker run -i --rm snapex-pay-mcp.
• MCP Registry name: pro.snapex/pay.
• Docs for people: https://pay.snapex.pro/mcp · REST reference: https://pay.snapex.pro/partner/merchant/docs · server card: https://pay.snapex.pro/.well-known/mcp.json · https://pay.snapex.pro/llms.txt
• Privacy policy: https://pay.snapex.pro/privacy · Terms: https://pay.snapex.pro/terms · Rules for merchants: https://pay.snapex.pro/rules · Support: https://pay.snapex.pro/#chat

How an agent uses it

1. Connect without a key. The catalogue tools (list_assets, get_fiat_rates, get_fees, list_static_address_networks) work at once.
2. Call create_account. It returns api_key (shown once), a cabinet login/password for a person, and mcp_personal_url. The new key is used right away: on the remote server for the rest of the MCP session, in the stdio package for the process (and it is saved to ~/.config/snapex-pay/credentials.json for the next runs).
3. Receive: create_invoice → give pay_url to the payer → get_invoice until paid. environment: "test" runs the whole flow without real money (a test invoice turns paid ~10 s after a coin is selected; the balance does not change).
4. Send: preview_payout (free quote) → create_payout with the preview_id and your own idempotency_key (irreversible; a retry with the same key never pays twice).
5. The balance is kept in USDT: to get another coin, pay out in that coin. preview_conversion → create_conversion converts other assets an older account still holds.

Every error answer says what to do next (what_to_do), e.g. unauthorized → call create_account; rate_limited → wait retry_after_seconds.

Connect

Claude Code

claude mcp add --transport http snapex-pay https://pay.snapex.pro/mcp
# with an existing key:
claude mcp add --transport http snapex-pay https://pay.snapex.pro/mcp --header "Authorization: Bearer smk_…"

Cursor — ~/.cursor/mcp.json

{
  "mcpServers": {
    "snapex-pay": { "url": "https://pay.snapex.pro/mcp" }
  }
}

Add "headers": { "Authorization": "Bearer smk_…" } to keep one account across sessions.

VS Code — .vscode/mcp.json

{
  "servers": {
    "snapex-pay": { "type": "http", "url": "https://pay.snapex.pro/mcp" }
  }
}

Windsurf — ~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "snapex-pay": { "serverUrl": "https://pay.snapex.pro/mcp" }
  }
}

Cline — cline_mcp_settings.json

{
  "mcpServers": {
    "snapex-pay": { "type": "streamableHttp", "url": "https://pay.snapex.pro/mcp" }
  }
}

Step-by-step for AI installers: llms-install.md.

Gemini CLI

As an extension (this repository has gemini-extension.json):

gemini extensions install https://github.com/snapexpay/snapex-pay-mcp

or in ~/.gemini/settings.json:

{
  "mcpServers": {
    "snapex-pay": { "httpUrl": "https://pay.snapex.pro/mcp" }
  }
}

Claude Desktop — claude_desktop_config.json

Remote server through mcp-remote:

{
  "mcpServers": {
    "snapex-pay": { "command": "npx", "args": ["-y", "mcp-remote", "https://pay.snapex.pro/mcp"] }
  }
}

or the local package:

{
  "mcpServers": {
    "snapex-pay": {
      "command": "npx",
      "args": ["-y", "snapex-pay-mcp"],
      "env": { "SNAPEX_API_KEY": "smk_…" }
    }
  }
}

(SNAPEX_API_KEY is optional: without it the agent calls create_account and the key is saved for the next runs.)

claude.ai and ChatGPT connectors

Add a custom connector with the URL https://pay.snapex.pro/mcp and no authentication. These clients cannot send headers, so after create_account take mcp_personal_url from its answer (also returned by get_account) and use it as the connector URL — every new chat then works with the same account. That URL contains a credential: treat it as a password.

OpenAI Responses API

{
  "type": "mcp",
  "server_label": "snapex_pay",
  "server_url": "https://pay.snapex.pro/mcp",
  "headers": { "Authorization": "Bearer smk_…" },
  "require_approval": { "always": { "tool_names": ["create_payout", "create_conversion"] } }
}

Other clients and catalogs

The repository carries the manifests the catalogs read: server.json (official MCP Registry), glama.json (Glama), gemini-extension.json + GEMINI.md (Gemini CLI), lhm.plugin.json (LobeHub), .cursor-plugin/plugin.json + mcp.json (Cursor Marketplace), plugin.json (Agent Plugins / Kiro), llms-install.md (Cline).

Docker

docker build -t snapex-pay-mcp .
docker run -i --rm -e SNAPEX_API_KEY=smk_… snapex-pay-mcp

Tools

Account

Catalogue (no key needed)

Balance

Receive

Send (payouts)

Exchange

Webhooks

Resources: snapex://docs/quickstart, snapex://docs/webhooks. Prompts: accept_crypto_payment, send_crypto_payout.

Environment (stdio package)

Safety

• An agent moves only its own account's money; a new account starts at zero.
• The key and the generated password are shown once. A person can open the cabinet with the login and password and revoke or rotate keys there.
• Payouts are two-step (quote, then send) and need an idempotency_key; create_payout, create_conversion and rotate_webhook_secret are marked destructiveHint, so clients can ask before running them.
• Limits: a few new accounts per IP per hour; about 120 API calls a minute per key; payouts 5 a minute and 30 an hour.
• Rules for what can be sold: https://pay.snapex.pro/rules.

Development

The tool list is generated from the SnapEX Pay server (app/Mcp/McpToolCatalog.php):

php artisan mcp:export-tools      # writes src/tools.json, syncs the version of the manifests and LobeHub's tools
npm ci && npm test                # build + offline smoke test with the official MCP SDK client
SNAPEX_E2E_BASE_URL=http://127.0.0.1:8765 node test/smoke.mjs   # full flow against a local (never production) server

Support

Chat: https://pay.snapex.pro/#chat · Privacy: https://pay.snapex.pro/privacy · Terms: https://pay.snapex.pro/terms