by OpenAI
Access OpenAI GPT-5.2, the best model for coding and agentic tasks across industries. Also supports GPT-5 mini for fast, affordable responses on well-defined tasks.
Install the x402 MCP server to let your AI agent access this data with automatic USDC payments on Base.
Required: You need a SerenDB database to store query results.
Get your connection string from the SerenDB Console under your database settings.
Add to claude_desktop_config.json:
{
"mcpServers": {
"x402": {
"command": "npx",
"args": ["@serendb/x402-mcp-server"],
"env": {
"X402_GATEWAY_URL": "https://x402.serendb.com",
"WALLET_PRIVATE_KEY": "0x...",
"BASE_RPC_URL": "https://mainnet.base.org",
"SERENDB_CONNECTION_STRING": "postgresql://..."
}
}
}
}Replace 0x... with your wallet private key and postgresql://... with your SerenDB connection string.
claude mcp add x402 \ -e X402_GATEWAY_URL=https://x402.serendb.com \ -e WALLET_PRIVATE_KEY=0x... \ -e BASE_RPC_URL=https://mainnet.base.org \ -e "SERENDB_CONNECTION_STRING=postgresql://..." \ -- npx -y @serendb/x402-mcp-server
claude mcp add x402 ` -e X402_GATEWAY_URL=https://x402.serendb.com ` -e WALLET_PRIVATE_KEY=0x... ` -e BASE_RPC_URL=https://mainnet.base.org ` -e "SERENDB_CONNECTION_STRING=postgresql://..." ` '--' npx -y @serendb/x402-mcp-server
Replace 0x... with your wallet private key and postgresql://... with your SerenDB connection string.
gemini mcp add x402 \ -e X402_GATEWAY_URL=https://x402.serendb.com \ -e WALLET_PRIVATE_KEY=0x... \ -e BASE_RPC_URL=https://mainnet.base.org \ -e "SERENDB_CONNECTION_STRING=postgresql://..." \ -- npx -y @serendb/x402-mcp-server
Replace 0x... with your wallet private key and postgresql://... with your SerenDB connection string.
codex mcp add x402 \ --env X402_GATEWAY_URL=https://x402.serendb.com \ --env WALLET_PRIVATE_KEY=0x... \ --env BASE_RPC_URL=https://mainnet.base.org \ --env "SERENDB_CONNECTION_STRING=postgresql://..." \ -- npx -y @serendb/x402-mcp-server
Important: Cursor has a 60s timeout. Pre-install globally first: npm install -g @serendb/x402-mcp-server
First, install globally to avoid timeout issues:
npm install -g @serendb/x402-mcp-server
Then add to ~/.cursor/mcp.json:
{
"mcpServers": {
"x402": {
"command": "x402-mcp-server",
"args": [],
"env": {
"X402_GATEWAY_URL": "https://x402.serendb.com",
"WALLET_PRIVATE_KEY": "0x...",
"BASE_RPC_URL": "https://mainnet.base.org",
"SERENDB_CONNECTION_STRING": "postgresql://..."
}
}
}
}Also works with Windsurf, Zed, and other MCP-compatible clients. See the full setup guide for details.
Access data directly via HTTP using the x402 payment protocol.
HTTP 402 with payment requirements (amount, wallet, EIP-712 data)X-PAYMENT header containing the signaturecurl -X POST https://x402.serendb.com/api/proxy \
-H "Content-Type: application/json" \
-d '{
"publisherId": "df224e6a-def9-498a-a3c0-0db89b883753",
"agentWallet": "0xYourWalletAddress",
"request": {
"method": "GET",
"path": "/endpoint"
}
}'This returns 402 Payment Required with the payment details you need to sign.
After signing the EIP-712 authorization, add the base64-encoded signature:
curl -X POST https://x402.serendb.com/api/proxy \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <base64-encoded-signature>" \
-d '{ ... }'Pay per API call via x402 protocol
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