Prototype · Preview: every server in the official registry, synced every 30 minutes. Reviews and accounts come in a later step.
PopNx MCPMCP servers for people who use AI · explained in plain words

Solmail

by ExpertVagabondversion 1.0.2i★ –iRuns on your computer
Registry nameio.github.ExpertVagabond/solmail

Install

Overview

Description from the maker (original English)

Send physical mail with Solana cryptocurrency - AI agents can send real letters worldwide

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

  • Connection: Runs on your computer
  • Transport: stdio
  • Category: Other
  • You need to fill in: SOLANA_PRIVATE_KEY

Install

Pick the AI app you use, then copy the settings.

Before you install

  • Basic checks: 1 of 1 passed
  • Runs on your computer with your user’s permissions (files, network, apps).
  • You fill in yourself: SOLANA_PRIVATE_KEY, SOLANA_NETWORK, SOLMAIL_API_URL, MERCHANT_WALLET

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

  • npmNode.js installed (for the npx command)

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "solmail": {
      "command": "npx",
      "args": [
        "-y",
        "solmail-mcp"
      ],
      "env": {
        "SOLANA_PRIVATE_KEY": "your-value",
        "SOLANA_NETWORK": "your-value",
        "SOLMAIL_API_URL": "your-value",
        "MERCHANT_WALLET": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add solmail --env SOLANA_PRIVATE_KEY=your-value --env SOLANA_NETWORK=your-value --env SOLMAIL_API_URL=your-value --env MERCHANT_WALLET=your-value -- npx -y solmail-mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "solmail": {
      "command": "npx",
      "args": [
        "-y",
        "solmail-mcp"
      ],
      "env": {
        "SOLANA_PRIVATE_KEY": "your-value",
        "SOLANA_NETWORK": "your-value",
        "SOLMAIL_API_URL": "your-value",
        "MERCHANT_WALLET": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "solmail": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "solmail-mcp"
      ],
      "env": {
        "SOLANA_PRIVATE_KEY": "your-value",
        "SOLANA_NETWORK": "your-value",
        "SOLMAIL_API_URL": "your-value",
        "MERCHANT_WALLET": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

  • SOLANA_PRIVATE_KEY secret required env
    Your agent's Solana wallet private key (base58 or JSON array format)
  • SOLANA_NETWORK env
    Solana network: devnet for testing, mainnet-beta for production
  • SOLMAIL_API_URL env
    SolMail API endpoint
  • MERCHANT_WALLET env
    Merchant wallet address for payments

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified with the GitHub account ExpertVagabond, which owns the repo

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • – Not applicable

    Endpoint responds

    This one runs on your computer; there is no internet endpoint

  • – Not applicable

    Sign-in with OAuth

    Runs on your computer and uses local settings instead

  • … Not checked yet

    No hidden instructions in tool descriptions

    Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Otheri

  • More stars than 0% of the other 32718 servers in this category
  • Published to the registry more recently than 2% of the other 32718 servers in this category
  • Basic checks equal to or better than 100% of the other 32718 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Solmail safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: SOLANA_PRIVATE_KEY

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.2) reached the registry 9 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Spec Driven Development, Remote Desktop Commander, MemberVault MCP by usefulapi

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Spec Driven Development

by formulahendry

MCP Server that facilitates spec-driven development workflows, not just Vibe Coding.

Runs on your computer★ 440MITUpdated 14 months ago
Install

Remote Desktop Commander

by desktop-commander

Remote Desktop Commander: use files, terminal and processes on your own computers from any AI app.

Runs in the cloud★ 211Updated 2 days ago
Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

:mailbox_with_mail: solmail-mcp

Send real physical mail using Solana cryptocurrency from your AI agent. A Model Context Protocol server that enables Claude and other AI agents to send physical letters and postcards to real addresses worldwide, paid with SOL. Built for the Colosseum Agent Hackathon (#47).

Install

npx solmail-mcp@latest

Add to your MCP config:

{

"mcpServers": { "solmail": { "command": "npx", "args": ["-y", "solmail-mcp"], "env": { "SOLANA_NETWORK": "devnet", "SOLANA_PRIVATE_KEY": "your_base58_private_key" } } } }

Features

  • Physical Mail -- Letters printed and mailed to 200+ countries via Lob.com
  • Solana Payments -- Pay with SOL on devnet (testing) or mainnet (production)
  • Non-Custodial -- Direct wallet control, no intermediaries
  • AI-Native -- Built specifically for MCP agent integration
  • Demo Mode -- Test with devnet SOL and Lob test API at zero cost

Tools (4)

ToolDescription
get_mail_quoteGet price quote for sending mail (country, color options)
send_mailSend a physical letter with Solana payment
get_wallet_balanceCheck agent wallet SOL balance
get_wallet_addressGet wallet address for funding

Usage Example

You: Send a thank you note to John Doe at 123 Main St, San Francisco, CA 94102

Claude: [calls get_mail_quote] Cost: $1.50 (~0.015 SOL) for domestic US mail [calls send_mail] Letter sent! Letter ID: ltr_abc123 Tracking: 9400000000000000000000 Payment: 0.015 SOL (tx: 5j7s...) Delivery: 3-5 business days

How It Works

Agent composes letter --> MCP validates address --> Solana tx signed

--> Payment sent to merchant --> SolMail verifies on-chain --> Lob.com prints letter --> USPS delivers --> Tracking returned

Pricing

TypePriceSOL (at $100/SOL)
US Domestic$1.50~0.015 SOL
International$2.50~0.025 SOL
Color printing+$0.50+0.005 SOL
Solana tx fee~$0.00025~0.0000025 SOL

Configuration

VariableRequiredDescription
SOLANA_PRIVATE_KEYYesAgent wallet private key (base58)
SOLANA_NETWORKNodevnet (default) or mainnet-beta
SOLMAIL_API_URLNoAPI endpoint (default: https://solmail.online/api)
MERCHANT_WALLETNoCustom payment destination

Important: Create a dedicated wallet with limited funds for AI agents. Never use your primary wallet.

Development

npm install && npm run build

npm run dev # Watch mode npm start # Production

Related Projects

Contributing

  1. Fork the repository
  2. Create your feature branch (git checkout -b feature/my-feature)
  3. Commit your changes
  4. Open a Pull Request

Links

License

MIT -- Purple Squirrel Media

Ask PopNx