X402 Api

io.github.fernsugiPublished by GitHub account fernsugiv1.0.5Updated Oct 24, 2026

Eight paid DeFi tools: prices, gas, swaps, token security, holders, yields, funding and wallets

VerifiedSTDIODesktop onlyFinanceSecurity & Monitoring

Overview

AI-generated overview

A local MCP server giving assistants eight pay-per-call crypto and DeFi data tools, paid in USDC on Base via the x402 protocol.

What you can do
Fetch crypto prices and multi-chain gas prices with no parameters required, and get a single DEX swap quote for a token pair and amount, plus hourly perpetual funding rates for an asset or all assets on Hyperliquid and dYdX v4. Run token security scans for rug-pull and honeypot flags, sample top holders and supply share, and list DeFi yield pools filtered by chain and minimum TVL. Profile a wallet's observed balances and transaction counts. By default it only inspects payment requirements and returns the 402 details without paying.
When to use it
Useful when an assistant needs quick crypto market, gas, DEX quote, token risk, holder, yield, funding-rate or wallet data and you are willing to pay small per-call USDC fees. The inspect mode is a safe way to see what each call costs before enabling payments.
Requirements
Runs locally via npx or a global npm install (Node.js). Optional auto-pay needs the viem package, a Base wallet funded with USDC, and the X402_WALLET_PRIVATE_KEY environment variable. Optional settings: X402_API_BASE_URL, X402_MAX_PER_CALL_USDC (default 0.01), X402_EXPECTED_PAY_TO and X402_REFERRAL_SOURCE. Network access to the x402 API is required.
Before you install
Auto-pay spends real USDC on Base, 0.001 to 0.008 per call, and repeated calls charge again; set X402_MAX_PER_CALL_USDC before enabling it. X402_WALLET_PRIVATE_KEY is a wallet private key: keep it in local environment settings, outside Git, and fund the wallet only with what you can spend. Keep X402_EXPECTED_PAY_TO pinned to the official recipient unless you trust an alternative deployment. Some tool outputs are explicitly partial or indicative.

Installation

In SourceWeft

  1. Open X402 Api in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

@x402-api/mcp-server

[x402-api MCP server]

MCP server that gives Claude, ChatGPT, and any MCP-compatible AI agent access to pay-per-call crypto/DeFi data via the x402 protocol.

8 tools. No API keys. AI agents pay USDC micropayments on Base, per request.

Find this service: Official MCP Registry · Glama · Agent discovery manifest · OpenAPI.

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Tools

ToolAPI EndpointCostDescription
get_crypto_pricesGET /api/price-feed0.001 USDCBTC/ETH/SOL + top 24h movers
get_gas_pricesGET /api/gas-tracker0.001 USDCMulti-chain gas (ETH, Base, Polygon, Arbitrum)
get_dex_quotesGET /api/dex-quotes0.002 USDCOne ParaSwap aggregate route
scan_tokenGET /api/token-scanner0.003 USDCGoPlus security flags and heuristic
track_whalesGET /api/whale-tracker0.005 USDCTop-holder sample and supply share
scan_yieldsGET /api/yield-scanner0.005 USDCDefiLlama pool APYs and TVL
get_funding_ratesGET /api/funding-rates0.008 USDCHyperliquid and dYdX hourly rates
profile_walletGET /api/wallet-profiler0.008 USDCObserved Blockscout balances; partial coverage

Quick Start

Option A: Inspect mode (no payment needed)

Just run it — any 402 responses will return human-readable payment instructions:

bash
npx @x402-api/mcp-server

Claude will tell you what's needed when a tool requires payment.

Option B: Auto-pay mode (fully autonomous)

Install optional payment deps and set your wallet key:

bash
npm install -g @x402-api/mcp-servernpm install -g viemexport X402_WALLET_PRIVATE_KEY=0x<your_private_key>x402-api-mcp

The MCP server signs Base USDC EIP-3009 authorizations only when the API advertises that settlement mode. The default payment cap is 0.01 USDC per call. Fund the wallet with USDC on Base; the API operator sponsors gas in direct settlement mode.

Claude Desktop Integration

Add to your claude_desktop_config.json:

Without auto-pay (inspect mode)

json
{  "mcpServers": {    "x402-api": {      "command": "npx",      "args": ["@x402-api/mcp-server"]    }  }}

With auto-pay

json
{  "mcpServers": {    "x402-api": {      "command": "npx",      "args": ["@x402-api/mcp-server"],      "env": {        "X402_WALLET_PRIVATE_KEY": "0x<your_private_key>"      }    }  }}

Config file location:

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
  • Windows: %APPDATA%\Claude\claude_desktop_config.json
  • Linux: ~/.config/Claude/claude_desktop_config.json

Environment Variables

VariableRequiredDescription
X402_WALLET_PRIVATE_KEYOptionalBase wallet private key for EIP-3009 automatic payment. Requires viem.
X402_MAX_PER_CALL_USDCOptionalPer-call cap, default 0.01 USDC.
X402_API_BASE_URLOptionalOverride API URL (default: https://x402-api.fly.dev)

How x402 Payments Work

This API uses the x402 protocol — HTTP 402 Payment Required:

  1. Agent calls tool → MCP server makes API request
  2. Server returns 402 with payment details (amount, USDC address, Base network)
  3. Auto-pay mode: this client signs an EIP-3009 authorization and retries; the API settles it on Base
  4. Inspect mode: MCP returns 402 details without signing or paying

Payment details:

  • Token: USDC on Base mainnet
  • Address: 0x60264c480b67adb557efEd22Cf0e7ceA792DefB7
  • Chain: Base (chain ID 8453)
  • Amount: 0.001–0.008 USDC per call (< 1 cent USD)

Tool Reference

get_crypto_prices

No parameters. Returns current prices for BTC, ETH, SOL + top 24h movers.

Cost: 0.001 USDC

get_gas_prices

No parameters. Returns gas prices for Ethereum, Base, Polygon, Arbitrum — slow/standard/fast tiers.

Cost: 0.001 USDC

get_dex_quotes

Get one ParaSwap aggregate route. No independent comparison between DEX venues.

ParameterTypeRequiredDescription
fromstring✅Input token (e.g. "ETH", "0x...")
tostring✅Output token (e.g. "USDC")
amountstring✅Amount to swap (e.g. "1.5")
Cost: 0.002 USDC

scan_token

Token security scan — detects rug-pull flags, honeypot patterns, mint authority, etc.

ParameterTypeRequiredDescription
tokenstring✅Contract address or symbol (e.g. "PEPE")
Cost: 0.003 USDC

track_whales

Top-holder sample from GoPlus. Gini and recent transfer history unavailable.

ParameterTypeRequiredDescription
tokenstring✅Contract address or symbol
Cost: 0.005 USDC

scan_yields

Top DeFi yield opportunities across Aave, Compound, Morpho, Lido, Pendle, etc.

ParameterTypeRequiredDescription
chainstring❌Filter by chain: "ethereum", "base", "arbitrum", "polygon"
min_tvlnumber❌Minimum TVL in USD (e.g. 1000000)
Cost: 0.005 USDC

get_funding_rates

Hourly perpetual funding from Hyperliquid and dYdX v4. Spreads are indicative.

ParameterTypeRequiredDescription
assetstring❌Asset symbol (e.g. "BTC", "ETH"). All assets if omitted.
Cost: 0.008 USDC

profile_wallet

Observed priced wallet balances and available transaction counts. DeFi positions, PnL and risk score unavailable.

ParameterTypeRequiredDescription
addressstring✅Ethereum/Base wallet address (0x...)
Cost: 0.008 USDC

Development

bash
git clone https://github.com/fernsugi/x402-api-mcp-servercd x402-api-mcp-server
npm installnpm run buildnpm start

To test without a payment wallet, simply run and see the 402 responses:

bash
node dist/index.js

Links

License

MIT

Three runnable workflows

WorkflowToolsTotal USDC
Token checkscan_token + track_whales0.008
ETH fundingget_funding_rates0.008
Swap quote + gasget_dex_quotes + get_gas_prices0.003

Runnable Node examples start in inspect mode. Each demo has inputs, recorded provider output, coverage limits, a spending cap, and an agent prompt.

Optional X402_REFERRAL_SOURCE labels requests for first-party aggregate attribution (default mcp). It is a hint, not verified caller identity. The API journals no raw payer wallets, IP addresses, or signatures. X402_EXPECTED_PAY_TO pins the payment recipient to the official wallet by default. Tools advertise that auto-pay can spend money and repeated calls can incur another charge.

Cursor / other local MCP clients

Use the same mcpServers configuration shown above. For Cursor, put it in .cursor/mcp.json in your project. Inspect mode needs no wallet. Set X402_MAX_PER_CALL_USDC before enabling auto-pay; repeated calls spend again. Keep wallet credentials in local environment settings, outside Git.

Registry publication

The Publish MCP Registry GitHub workflow validates the matching npm version, then publishes server.json using GitHub OIDC. It runs on a published GitHub release or a manual dispatch from main. No npm token, GitHub PAT, or wallet key is stored in CI. Actions and official publisher source are pinned to verified commits. npm publication still happens separately before creating the release.

Source: README.md at commit 44bdf37

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

3
  1. v1.0.5LatestSep 30, 2026
  2. v1.0.4Sep 29, 2026
  3. v1.0.2Sep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

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  • Auth declared10 pts

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  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts