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Connect your MCP client to Hail

Hail runs a Model Context Protocol server. Add it to any MCP client. Your agent gets tools for calls, SMS, email, numbers, agents, and carrier verification after the client reconnects. You do not install an SDK.

After your first connection, manage authorized apps at hail.so/console/apps.

Setup guides for 7 MCP clients

ClaudeAnthropic
Claude.ai (Web), Claude Desktop, Claude CodeOpen the Claude guide
ChatGPTOpenAI
ChatGPT Web, ChatGPT Desktop, Custom GPTsOpen the ChatGPT guide
Codex CLIOpenAI
Codex CLI, Codex IDE Extension, Codex CloudOpen the Codex CLI guide
CursorAnysphere
Cursor Editor, Cursor CLI, Cloud AgentsOpen the Cursor guide
VS CodeGitHub Copilot
Copilot Chat, Agent Mode, VS Code CLIOpen the VS Code guide
Gemini CLIGoogle
Gemini CLI, Code Assist (VS Code and IntelliJ)Open the Gemini CLI guide
WindsurfDevin Desktop, Cognition
Devin Desktop Editor, Devin Local AgentOpen the Windsurf guide

Your client is not in the list

Email us the name of your client. You can also use the endpoint below.

Email a client request

Endpoint for other MCP clients

Any client that supports MCP over Streamable HTTP can connect. Paste the URL into the MCP server field of your client. The client starts OAuth on the first call. You do not copy an API key.

https://mcp.hail.so
ProtocolMCP over Streamable HTTP
AuthOAuth 2.1. Click Allow on the first connection.
Voiceplace_call, get_call, list_calls
SMSsend_sms, get_sms, list_sms
Emailsend_email, get_email, list_emails, get_email_stats, get_email_events, get_email_raw, get_email_attachment, upload_email_attachment, list_email_domains
Contactscreate_contact, lookup_contact, list_contacts
Numbersquote_numbers, list_number_regions, acquire_number, list_numbers, get_number, release_number, route_number
Agentslist_agents, create_agent, get_agent, update_agent, delete_agent
Verificationget_verification_requirements, list_verifications, get_verification, cancel_verification, submit_verification
Eventsget_events
Accountwhoami
WebhooksPOST, signed, retry-safe
Regionus-east, eu-west, ap-south

Set up an agent from the skill file

Agents such as OpenClaw and Hermes read setup instructions from a skill file. Give the agent the URL hail.so/skill.md. The agent reads the instructions, creates an account, sends messages, and reads replies. A person does not need to do the setup.

  • Hermes installs a skill from a URL with one command. The command is in the Hermes code panel. The MCP server also works. Add it under mcp_servers in ~/.hermes/config.yaml.
  • OpenClaw uses its MCP config. Add Hail under mcp.servers in ~/.openclaw/openclaw.json. Then run openclaw mcp login hail.
  • Other agents can read the skill file if they can fetch a URL. The file is plain markdown.
Hermes
hermes skills install https://hail.so/skill.md
Other agents
curl https://hail.so/skill.md

The MCP server has 37 tools. The skill file covers sign-up, sending, and inbound messages. To buy a number, an agent quotes it, then confirms the exact total price. Releasing a number or deleting an agent needs a typed confirmation.