MCP Server Setup

Quick Setup

Install httpcat-cli

Choose your preferred installation method:

npx (Recommended for MCP)
Global Install
Homebrew

No installation needed! The MCP config will use npx to run httpcat automatically.

npm install -g httpcat-cli

brew tap hathbanger/httpcat
brew install httpcat

Get your private key

You’ll need a Base-compatible private key with USDC for trading.

Never hardcode your private key in config files. Use environment variables or your MCP client’s secrets management.

Configure your MCP client

Follow the instructions below for your specific client.

Test the connection

Ask your AI assistant:

"Check my httpcat balance"

If it responds with your ETH and USDC balances, you’re all set!

Cursor Configuration

Cursor supports MCP natively. Configure in your MCP settings:

Location

macOS/Linux: ~/.cursor/mcp_settings.json
Windows: %APPDATA%\Cursor\mcp_settings.json

Or use Cursor’s UI: Settings → Extensions → MCP Servers

Configuration (npx)

{
  "mcpServers": {
    "httpcat": {
      "command": "npx",
      "args": ["-y", "httpcat-cli", "mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Using npx ensures you always get the latest version of httpcat-cli without manual updates.

Configuration (Global Install)

If you installed httpcat-cli globally:

{
  "mcpServers": {
    "httpcat": {
      "command": "httpcat",
      "args": ["mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Using Environment Variables

Instead of hardcoding the private key:

{
  "mcpServers": {
    "httpcat": {
      "command": "npx",
      "args": ["-y", "httpcat-cli", "mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "${HTTPCAT_PRIVATE_KEY}"
      }
    }
  }
}

Then set in your shell:

export HTTPCAT_PRIVATE_KEY="0x..."

Restart Cursor

After saving the configuration, restart Cursor to load the MCP server.

Claude Desktop Configuration

Claude Desktop (Anthropic’s official app) supports MCP.

Location

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

Configuration (npx)

{
  "mcpServers": {
    "httpcat": {
      "command": "npx",
      "args": ["-y", "httpcat-cli", "mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Configuration (Global Install)

{
  "mcpServers": {
    "httpcat": {
      "command": "httpcat",
      "args": ["mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Restart Claude Desktop

Quit Claude Desktop completely and restart to load the MCP server.

Custom MCP Clients

For other MCP-compatible clients:

Standard MCP Configuration

{
  "servers": {
    "httpcat": {
      "command": "npx",
      "args": ["-y", "httpcat-cli", "mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Programmatic Setup

If you’re building an MCP client:

import { MCPClient } from '@modelcontextprotocol/sdk';

const client = new MCPClient({
  command: 'npx',
  args: ['-y', 'httpcat-cli', 'mcp-server'],
  env: {
    HTTPCAT_PRIVATE_KEY: process.env.HTTPCAT_PRIVATE_KEY
  }
});

await client.connect();

Environment Configuration

Available Environment Variables

Configure httpcat behavior via environment variables:

{
  "mcpServers": {
    "httpcat": {
      "command": "npx",
      "args": ["-y", "httpcat-cli", "mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x...",
        "HTTPCAT_NETWORK": "eip155:84532",
        "HTTPCAT_AGENT_URL": "https://agent.402.cat",
        "HTTPCAT_RPC_URL": "https://sepolia.base.org"
      }
    }
  }
}

Variable	Description	Default
`HTTPCAT_PRIVATE_KEY`	Your private key	Required
`HTTPCAT_NETWORK`	Network: `eip155:84532` (testnet) or `eip155:8453` (mainnet)	Auto-detected
`HTTPCAT_AGENT_URL`	Agent endpoint	`https://agent.402.cat`
`HTTPCAT_RPC_URL`	Custom RPC URL	Base default

Network Selection

Base Sepolia (Testnet)
Base (Mainnet)

{
  "env": {
    "HTTPCAT_PRIVATE_KEY": "0x...",
    "HTTPCAT_NETWORK": "eip155:84532"
  }
}

Perfect for:

Testing and learning
Free testnet USDC
No financial risk

{
  "env": {
    "HTTPCAT_PRIVATE_KEY": "0x...",
    "HTTPCAT_NETWORK": "eip155:8453"
  }
}

Perfect for:

Real token launches
Production trading
Actual value transfers

If you don’t specify HTTPCAT_NETWORK, it will be auto-detected from your wallet’s transactions.

Security Best Practices

Private Key Management

DO:

Use environment variables
Use your MCP client’s secrets management
Use different keys for testnet and mainnet
Rotate keys regularly

DON’T:

Commit keys to version control
Hardcode keys in config files
Share keys in screenshots
Reuse keys across projects

Environment Variables

Best approach:

Create a .env file (add to .gitignore):
```
HTTPCAT_PRIVATE_KEY=0x...
```
Load in your shell:
```
source .env
```

Reference in MCP config:

{
  "env": {
    "HTTPCAT_PRIVATE_KEY": "${HTTPCAT_PRIVATE_KEY}"
  }
}

Testing Setup

Always test with testnet first:

Use Base Sepolia network
Get free testnet tokens from faucets
Verify tools work correctly
Then switch to mainnet with real funds

Backup & Recovery

Back up your seed phrase (not private key)
Store offline in secure location
Never share with anyone
Consider hardware wallet for mainnet

Verifying Setup

Test Connection

Ask your AI assistant to run a health check:

"Check if httpcat is working"

Expected response:

The httpcat agent is healthy and running on [network].

Test Balance

"What's my wallet balance?"

Expected response:

Your wallet has:
- ETH: 0.005
- USDC: 10.00

Test Token Info

"Get information about MOON token"

Expected response should include token details, price, and market cap.

Troubleshooting

MCP server not found

Symptoms: AI assistant says httpcat tools are unavailableSolutions:

Restart your MCP client completely
Verify config file location

Check command path:

which httpcat  # For global install
npx httpcat-cli --version  # For npx

Check MCP client logs for errors

Private key errors

Symptoms: “Invalid private key” or “Authentication failed”Solutions:

Verify key format starts with 0x
Ensure key is 64 hex characters (+ 0x prefix)
Check environment variable is set:
```
echo $HTTPCAT_PRIVATE_KEY
```
Try hardcoding temporarily to test

Network connection errors

Symptoms: “Cannot connect to agent” or timeout errorsSolutions:

Check internet connection
Verify agent URL is reachable:
```
curl https://agent.402.cat/health
```
Check for firewall/proxy issues
Try custom agent URL if needed

Tool execution failures

Symptoms: Tools return errors or unexpected resultsSolutions:

Check wallet has USDC for operations
Check wallet has ETH for gas fees
Verify network matches your funds
Try the same operation via CLI:
```
httpcat balance
httpcat health
```
Check httpcat-cli logs

Version mismatch

Symptoms: Tools behave differently than documentedSolutions:

Update to latest version:
```
npm update -g httpcat-cli
```
For npx, it auto-updates on each run
Check version:
```
httpcat --version
```
Clear npm cache if needed:
```
npm cache clean --force
```

Advanced Configuration

Multiple Environments

Configure different environments for different use cases:

{
  "mcpServers": {
    "httpcat-testnet": {
      "command": "npx",
      "args": ["-y", "httpcat-cli", "mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x...testnet_key",
        "HTTPCAT_NETWORK": "eip155:84532"
      }
    },
    "httpcat-mainnet": {
      "command": "npx",
      "args": ["-y", "httpcat-cli", "mcp-server"],
      "env": {
        "HTTPCAT_PRIVATE_KEY": "0x...mainnet_key",
        "HTTPCAT_NETWORK": "eip155:8453"
      }
    }
  }
}

Then specify which to use when talking to AI:

"Using httpcat-testnet, check my balance"
"Using httpcat-mainnet, create a token"

Custom RPC Endpoint

Use a custom RPC provider for better reliability:

{
  "env": {
    "HTTPCAT_PRIVATE_KEY": "0x...",
    "HTTPCAT_RPC_URL": "https://base-mainnet.g.alchemy.com/v2/YOUR_KEY"
  }
}

Recommended providers:

Next Steps

Tools Reference

Learn all 11 available MCP tools

CLI Commands

Understand underlying CLI commands

Examples

See complete workflow examples

API Reference

Build custom integrations

Once configured, try asking your AI: “Create a test token on httpcat” to verify everything works!

Getting Started

httpcat-cli

MCP Server

Core Concepts

Quick Setup

Cursor Configuration

Location

Configuration (npx)

Configuration (Global Install)

Using Environment Variables

Restart Cursor

Claude Desktop Configuration

Location

Configuration (npx)

Configuration (Global Install)

Restart Claude Desktop

Custom MCP Clients

Standard MCP Configuration

Programmatic Setup

Environment Configuration

Available Environment Variables

Network Selection

Security Best Practices

Verifying Setup

Test Connection

Test Balance

Test Token Info

Troubleshooting

Advanced Configuration

Multiple Environments

Custom RPC Endpoint

Next Steps

Tools Reference

CLI Commands

Examples

API Reference

Getting Started

httpcat-cli

MCP Server

Core Concepts

​Quick Setup

​Cursor Configuration

​Location

​Configuration (npx)

​Configuration (Global Install)

​Using Environment Variables

​Restart Cursor

​Claude Desktop Configuration

​Location

​Configuration (npx)

​Configuration (Global Install)

​Restart Claude Desktop

​Custom MCP Clients

​Standard MCP Configuration

​Programmatic Setup

​Environment Configuration

​Available Environment Variables

​Network Selection

​Security Best Practices

​Verifying Setup

​Test Connection

​Test Balance

​Test Token Info

​Troubleshooting

​Advanced Configuration

​Multiple Environments

​Custom RPC Endpoint

​Next Steps

Tools Reference

CLI Commands

Examples

API Reference

Quick Setup

Cursor Configuration

Location

Configuration (npx)

Configuration (Global Install)

Using Environment Variables

Restart Cursor

Claude Desktop Configuration

Location

Configuration (npx)

Configuration (Global Install)

Restart Claude Desktop

Custom MCP Clients

Standard MCP Configuration

Programmatic Setup

Environment Configuration

Available Environment Variables

Network Selection

Security Best Practices

Verifying Setup

Test Connection

Test Balance

Test Token Info

Troubleshooting

Advanced Configuration

Multiple Environments

Custom RPC Endpoint

Next Steps