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io.github.tusk80/fastx402

Official registry Finance and payments

60+ pay-per-call tools for agents (data, dates, QR, crypto, web), paid in USDC via x402.

Source code Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package fastx402-mcp
Claude Code 
claude mcp add fastx402 -e 'FASTX402_EVM_PRIVATE_KEY=<your fastx402_evm_private_key>' -e 'FASTX402_SOLANA_PRIVATE_KEY=<your fastx402_solana_private_key>' -e 'FASTX402_MAX_USD_PER_CALL=<FASTX402_MAX_USD_PER_CALL>' -e 'FASTX402_MAX_USD_PER_DAY=<FASTX402_MAX_USD_PER_DAY>' -- npx -y fastx402-mcp@0.1.1
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "fastx402": {
            "command": "npx",
            "args": [
                "-y",
                "fastx402-mcp@0.1.1"
            ],
            "env": {
                "FASTX402_EVM_PRIVATE_KEY": "<your fastx402_evm_private_key>",
                "FASTX402_SOLANA_PRIVATE_KEY": "<your fastx402_solana_private_key>",
                "FASTX402_MAX_USD_PER_CALL": "<FASTX402_MAX_USD_PER_CALL>",
                "FASTX402_MAX_USD_PER_DAY": "<FASTX402_MAX_USD_PER_DAY>"
            }
        }
    }
}

Environment variables

  • FASTX402_EVM_PRIVATE_KEY secret Dedicated wallet key that pays in USDC on Base (0x + 64 hex)
  • FASTX402_SOLANA_PRIVATE_KEY secret Dedicated wallet key that pays in USDC on Solana (base58)
  • FASTX402_MAX_USD_PER_CALL Maximum USD per single payment (default 0.05)
  • FASTX402_MAX_USD_PER_DAY Maximum USD spent per day (default 1)

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. fastx402-mcp
  2. Quick start
  3. Settings
  4. How paying works
  5. Safety
  6. Links

fastx402-mcp

80+ small, fast tools for your AI agent, paid per call in USDC with x402. No account, no API key, no subscription: your agent pays a fraction of a cent per successful call, on Base or Solana.

Tools include background removal, image to SVG, image and video conversion, video to GIF, text to speech, QR codes, YAML/XML/CSV/JSON conversion, Markdown to HTML, text diffs, date math and formatting, cron descriptions, time zones, color conversion, unit conversion, IP and DNS lookups, email/IBAN/ISBN validation, hashing and JWT decoding, Ethereum/Base/Solana balances, token info, transaction status, gas prices, ENS and Basename resolution, web page text, screenshots, PDF text, OCR and audio transcription. The list is read live from fastx402.tools, so new tools appear without updating this package.

Quick start

Claude Desktop, one click: download fastx402.mcpb from the latest release, double-click it, and fill in the form (wallet key and limits). Done.

Any MCP client, by config:

Create a new, dedicated wallet and put a few dollars of USDC in it (on Base, or on Solana). Never use your main wallet.

Claude Desktop (claude_desktop_config.json), Cursor (~/.cursor/mcp.json) and most MCP clients:

{
  "mcpServers": {
    "fastx402": {
      "command": "npx",
      "args": ["-y", "fastx402-mcp"],
      "env": {
        "FASTX402_EVM_PRIVATE_KEY": "0xYOUR_DEDICATED_WALLET_KEY",
        "FASTX402_MAX_USD_PER_DAY": "1"
      }
    }
  }
}

For Solana, set FASTX402_SOLANA_PRIVATE_KEY (base58 secret key) instead of, or next to, the EVM key.

Settings

VariableDefaultWhat it does
FASTX402_EVM_PRIVATE_KEYnoneWallet that pays in USDC on Base (0x + 64 hex)
FASTX402_SOLANA_PRIVATE_KEYnoneWallet that pays in USDC on Solana (base58, 64-byte secret key)
FASTX402_MAX_USD_PER_CALL0.05Refuses any single payment above this, whatever the server asks
FASTX402_MAX_USD_PER_DAY1Stops paying once this much was spent today (kept in ~/.fastx402-mcp/spend.json)
FASTX402_URLhttps://fastx402.toolsThe shop to use

Without a key the server still lists every tool, so you can look before you pay.

How paying works

  1. The agent calls a tool; the server sends the request to fastx402.tools.
  2. The shop answers 402 Payment Required with the exact price.
  3. Your key signs a USDC authorization for that amount only, locally. The key never leaves your machine.
  4. The request is repeated with the signature; the facilitator settles it on-chain (it also pays the network fee) and the answer comes back.

Failed calls (bad input 400, source down 502) are not charged. Prices are shown in every tool description.

Safety

  • Use a dedicated wallet with a small balance; the limits above are a second line of defence.
  • The key is only used to sign x402 USDC payments to fastx402.tools for the listed price.
  • Source: this single file, index.js. Read it.

MIT License.

Frequently asked questions

What is io.github.tusk80/fastx402?

60+ pay-per-call tools for agents (data, dates, QR, crypto, web), paid in USDC via x402.

How do I install io.github.tusk80/fastx402?

It runs on your machine. In Claude Code: claude mcp add fastx402 -e 'FASTX402_EVM_PRIVATE_KEY=<your fastx402_evm_private_key>' -e 'FASTX402_SOLANA_PRIVATE_KEY=<your fastx402_solana_private_key>' -e 'FASTX402_MAX_USD_PER_CALL=<FASTX402_MAX_USD_PER_CALL>' -e 'FASTX402_MAX_USD_PER_DAY=<FASTX402_MAX_USD_PER_DAY>' -- npx -y fastx402-mcp@0.1.1. For other clients, paste the JSON configuration from this page into their MCP settings.

Does io.github.tusk80/fastx402 need an API key?

Yes. It expects FASTX402_EVM_PRIVATE_KEY, FASTX402_SOLANA_PRIVATE_KEY, which you set in its configuration.

Is io.github.tusk80/fastx402 open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains io.github.tusk80/fastx402?

It is published by tusk80. AI.tn lists it but does not maintain or endorse it.

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