Connect Codex CLI to Hail over MCP
Codex adds MCP servers with the codex mcp command. Run two commands. The CLI, the VS Code extension, and Codex cloud then share the Hail tools.
Works in Codex CLI, Codex IDE Extension, and Codex Cloud.
Setup
1
Add Hail to Codex CLI
Add the Hail MCP server with the snippet below. Run codex mcp add, then run codex mcp login.
Terminal
codex mcp add hail --url https://mcp.hail.so codex mcp login hail
2
Approve access and send a test prompt
Reload the client. On first use, the client opens a browser tab. Sign in to Hail or create an account. Click Allow. Then send the prompt below. The setup works if Hail places the call or sends the message.
"Use hail to text me when the test suite passes."Notes
Two stepsadd writes the config. login opens the browser consent.
Config file[mcp_servers.hail] with url = https://mcp.hail.so in ~/.codex/config.toml.
Old buildsUpgrade Codex. Do not set experimental_use_rmcp_client.
Shared configCLI, IDE extension, and cloud share it. Check with codex mcp list.
URLNo trailing slash. Audience checks are exact-string.
PrivacyHail does not receive chat history. Hail receives only tool arguments.
ManageRevoke or manage this app at hail.so/console/apps.
Self-hostSet HAIL_API_KEY as the bearer. See docs/mcp.
Place your first call from Codex CLI
Self-host with your own carrier, or use a managed number from Hail.
