This article shows you how to register the Cryptohopper Market Data MCP server in Codex so you can query market data from your ChatGPT-powered coding sessions.
Prerequisites
An active ChatGPT subscription
Codex installed on your machine
Either your Cryptohopper MCP API key (bearer token) — found in your user profile under MCP API Keys — or use OAuth2 authentication (no key required).
Setup
Open Codex and start a new session.
Choose one of the following authentication methods and paste the corresponding configuration:
Option A — API Key (bearer token)
Replace YOUR_REAL_MCP_API_KEY with your actual bearer token. You can find this token in your Cryptohopper profile under MCP API Keys.
{
"mcpServers": {
"Cryptohopper.com Market Data": {
"type": "http",
"url": "https://mcp-data.cryptohopper.com/mcp",
"headers": {
"Authorization": "Bearer YOUR_REAL_MCP_API_KEY"
}
}
}
}Option B — OAuth2 (no API key required)
{
"mcpServers": {
"Cryptohopper.com Market Data": {
"type": "http",
"url": "https://mcp-data.cryptohopper.com/mcp"
}
}
}3. When asked “Do you want me to update your Codex config so this MCP server is registered?”, choose Yes, and don’t ask again this session.
4. Restart Codex and open a new chat.
5. Type: “I want to use the Cryptohopper MCP.”
6. If Codex asks for further confirmations, keep selecting Yes, don’t ask again.
7. Once the server is active, start asking your questions.
Doesn't it work?
Authentication errors: If you're using an API key, verify your bearer token is correct and still valid. You can regenerate it in your Cryptohopper profile under MCP API Keys. If you're using OAuth2, make sure you completed the authentication flow when prompted.
Server not registered: Make sure you accepted the config update prompt and restarted Codex afterwards.
MCP not responding: Confirm the URL is exactly https://mcp-data.cryptohopper.com/mcp and that your machine can reach it (check firewall or VPN settings).
Commands fail inside Codex: Install any required dependencies for the task before prompting Codex again.