Unified Airdrop Eligibility: Bridging Browser Tools and LLMs via MCP

Paste a wallet, get a personal airdrop verdict — and call the same logic from any LLM

Weston G has released a dual-surface tool that evaluates 14 hand-verified on-chain rules for airdrop eligibility. The system bridges a browser-based frontend with a Model Context Protocol (MCP) server to ensure consistent results across all interfaces.

Why This Matters

Traditional airdrop directories often provide low-signal data by matching broad chain activity rather than specific contract interactions. This tool addresses the signal-to-noise problem by utilizing client-side RPC fanning and a single source of truth for rules, preventing data drift. By exposing this logic via MCP, developers can integrate high-fidelity on-chain verification directly into LLM workflows like Claude or Cursor, bypassing the need for fragile web scraping.

Key Insights

• The system evaluates 14 rules against 42 curated entries, resolving in 2-5 seconds for complex wallets like vitalik.eth.
• JSON-RPC batching optimizes performance by bundling eth_getTransactionCount and eth_call requests into a single POST per EVM chain.
• A single-file source of truth (eligibility-rules.json) is shared between the Astro web frontend and the MCP serverless function to ensure zero drift.
• The MCP tool returns structured JSON verdicts categorized into eligible, partial, skip, manual, and unavailable buckets for LLM consumption.

Working Examples

Calling the check_eligibility tool via the MCP JSON-RPC interface

curl -s -X POST https://web3-discover.vercel.app/api/mcp \
-H 'content-type: application/json' \
-d '{
"jsonrpc": "2.0",
"id": 7,
"method": "tools/call",
"params": {
"name": "check_eligibility",
"arguments": { "evm": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045" }
}
}'

Configuration for integrating the tool into Claude Desktop or Cursor

{
"mcpServers": {
"web3-discover": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://web3-discover.vercel.app/api/mcp"]
}
}
}

Prebuild script ensuring the MCP server and browser tool share the same rule registry

fs.copyFileSync(
path.join(ROOT, 'src/data/eligibility-rules.json'),
path.join(ROOT, 'api/_eligibility-rules.json'),
);

Practical Applications

• Integrating wallet eligibility checks into LLM chats (Claude/Cursor) to provide real-time decision support for crypto users.
• Using browser-side RPC calls to verify on-chain status without signature requirements or server-side address logging.
• Pitfall: Relying on broad ‘chain usage’ metrics which leads to high false-positive rates in airdrop discovery.
• Pitfall: Manual HTML scraping of directory sites which results in flaky data integration for automated agents.

References:

• https://web3-discover.vercel.app/tools/eligibility
• https://web3-discover.vercel.app/api/mcp
• https://dev.to/weston_g/paste-a-wallet-get-a-personal-airdrop-verdict-and-call-the-same-logic-from-any-llm-4ej0