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Whale Alert API

Official registry Other

Track large on-chain whale transactions on Ethereum and Base. x402 micropayment.

Source code Website 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).

Remote (sse)
Claude Code 
claude mcp add --transport sse whale-alert-api 'https://whale-alert.api.klymax402.com/mcp'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "whale-alert-api": {
            "type": "sse",
            "url": "https://whale-alert.api.klymax402.com/mcp"
        }
    }
}

Documentation

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

Contents
  1. Whale Alert API
  2. Quickstart -- MCP
  3. Quickstart -- HTTP (x402)
  4. Tools
  5. Example agent prompts
  6. Payment
  7. Part of klymax402
  8. License

Whale Alert API

Whale transaction tracker -- large on-chain transfers with sender, value, USD estimate. Market-moving alerts. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "whale-alert": {
      "url": "https://whale-alert.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl -X POST "https://whale-alert.api.klymax402.com/api/whales" \
  -H "Content-Type: application/json" \
  -d '{}'
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

ToolMethodPathPriceDescription
crypto_track_whale_transactionsPOST/api/whales$0.008Track large on-chain whale transactions
crypto_track_whale_transactions

Use this when you need to track large on-chain transactions (whale movements) on Ethereum or Base. Returns recent high-value transfers in JSON.

Parameters

NameTypeRequiredDescription
chainstringnoBlockchain: 'ethereum' or 'base' (default: ethereum)
minValuenumbernoMinimum transaction value in ETH (default: 100)

Returns

  • transactions -- array of whale transfers sorted by value descending
  • from -- sender wallet address
  • to -- receiver wallet address
  • valueEth -- transaction value in ETH
  • valueUsd -- estimated USD value at time of transfer
  • txHash -- transaction hash for on-chain verification
  • blockNumber -- block number of the transaction
  • timestamp -- when the transaction occurred

Example response:

{"transactions":[{"from":"0xab...","to":"0xcd...","valueEth":500.0,"valueUsd":1552500,"txHash":"0xef...","blockNumber":19845632,"timestamp":"2026-04-13T11:22:00Z"}],"chain":"ethereum","minValue":100,"totalFound":8}

When to use: detecting market-moving whale activity and smart money flows. Essential for trading signal generation and on-chain intelligence.

Not for: wallet balance (use wallet_get_portfolio), token prices (use finance_get_token_price), holder distribution (use token_get_holder_analysis).

Example agent prompts

  • "Track large on-chain transactions (whale movements) on Ethereum or Base"

Payment

  • Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
  • Network: Base L2 (eip155:8453)
  • Asset: USDC
  • Facilitator: Coinbase CDP (primary), PayAI (fallback)
  • Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

License

MIT

Frequently asked questions

What is Whale Alert API?

Track large on-chain whale transactions on Ethereum and Base. x402 micropayment.

How do I install Whale Alert API?

It runs as a remote server. In Claude Code: claude mcp add --transport sse whale-alert-api 'https://whale-alert.api.klymax402.com/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Whale Alert API need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Whale Alert API open source?

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

Who maintains Whale Alert API?

It is published by Br0ski777. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.