Hail

Connect it to your AI

Claude Code

claude mcp add --transport http hail-mcp https://mcp.hail.so/

Claude, ChatGPT, Cursor and other apps

Add it as a custom connector with this URL (Streamable HTTP):

https://mcp.hail.so/

Cursor, VS Code and other apps (mcp.json)

{
  "mcpServers": {
    "hail-mcp": {
      "url": "https://mcp.hail.so/"
    }
  }
}

Tools it offers

38 tools, as the server itself reported during our check on Oct 31, 2026.

• place_callOriginate an outbound phone call. Provide ``system_prompt`` (mode A — Hail's bundled fallback LLM uses this prompt) or ``llm`` (mode B — bring your own OpenAI-compatible endpoint as ``{"base_url": ..., "api_key": ..., "m
• send_emailSend an outbound email through your configured SES sender. ``to`` is a non-empty list of RFC-style email addresses. At least one of ``body_text`` / ``body_html`` is required (both is fine — multipart-alternative). Prefer
• upload_email_attachmentUpload a file to attach to a future outbound email. ``content_base64`` is the file's raw bytes, base64-encoded. Returns ``{"id": ..., "filename": ..., "content_type": ..., "size_bytes": ...}`` — pass ``id`` in ``send_ema
• get_callFetch the current state of one call by id. Use this after ``place_call`` (or to check on any prior call) to read the call's latest ``status`` and timing fields. Returns the API's ``CallResponse`` as a dict, or ``{"error"
• list_callsList recent calls in your organization, newest first. Cursor-paginated: pass the previous response's ``next_cursor`` to fetch the next page. ``status`` (one of queued, dialing, ringing, in_progress, completed, failed, bu
• send_smsSend an outbound SMS. ``to`` must be E.164 (e.g. ``+14155551234``). ``body`` is the message text. With no ``from_``: destinations where the sender-ID carrier delivers a dynamic alphanumeric sender ID unchanged (about 110
• get_smsFetch the current state of one SMS by id. Use this after ``send_sms`` to check delivery status. Example: get_sms(sms_id="...")
• list_smsPage through recent SMS messages for your organization. ``status`` filters to one of: queued, sent, delivered, failed, undelivered, received. ``to`` filters to messages sent to a specific E.164 number. Paginate with the
• get_emailFetch the full record of one email by id. Returns the complete row — including ``body_text`` / ``body_html`` and (for inbound mail) the ``in_reply_to`` / ``message_id`` headers and ``spam``/``virus``/``spf``/``dkim``/``d
• list_emailsList emails in your organization, newest first. Cursor-paginated: pass the previous response's ``next_cursor`` to fetch the next page. Two optional server-side filters: * ``direction`` — ``outbound`` or ``inbound``. Pass
• get_email_rawGet a fetchable URL for an email's original MIME source. Returns ``{"url": "<presigned-s3-url>"}`` — a short-lived (~5 minute) link to the full raw RFC822 message. Fetch the URL directly to read the complete original; it
• get_email_attachmentGet a fetchable URL for one inbound email attachment. ``attachment_id`` comes from an item in ``get_email``'s ``attachments`` list. Returns ``{"url": "<presigned-s3-url>"}`` — a short-lived (~5 minute) link to the attach
• get_email_eventsDelivery/engagement timeline (sent→delivered→opened…) for one email. Chronological lifecycle events for a single email — use this to see exactly what happened to one message (bounced? opened? clicked?) rather than the ac
• get_email_statsAccount-level email deliverability stats (counts, rates, time series). Aggregates across your whole organization's outbound mail over a window — use this for "how's deliverability doing" rather than one message's history
• get_eventsPage through events from across the org or one resource. Pass ``id="<type>:<uuid>"`` to narrow to a single resource — supported types are ``call``, ``email``, and ``sms`` (e.g. ``id="sms:<uuid>"`` after ``send_sms``). Wh
• list_agentsList the workspace's saved agents: the brains that answer calls and texts on its numbers, and that ``place_call`` can use via ``agent_id``. Returns ``{"items": [{"id", "name", "system_prompt", "first_message", "ai_disclo
• create_agentSave an agent. Then call ``route_number`` so a number answers with it, or pass its id as ``agent_id`` to ``place_call``. ``system_prompt`` is what the agent follows. ``first_message`` is spoken after the AI line; omit it
• route_numberChoose which agent answers a number's calls and texts. ``voice_agent_id`` makes the number answer calls with that agent (Hail registers it for inbound at the carrier and LiveKit); ``clear_voice=True`` stops answering cal
• quote_numbersCompare live phone-number offers from the carriers. Read-only: it buys nothing and charges nothing. ``country_code`` is an ISO alpha-2 code such as ``"US"``. ``capabilities`` is ``["voice"]``, ``["sms"]`` or both (defaul
• acquire_numberBuys a real phone number. It charges the setup fee and the first month now and renews monthly. Call quote_numbers first. Pass the offer's quote_id, country_code, number_type, and confirm_total_cents = monthly_cents + set
• list_numbersList the workspace's dedicated phone numbers, newest first. ``limit`` is 1..200 (default 50). Pass the returned ``next_cursor`` as ``cursor`` for the next page. Returns ``{"items": [{"id", "e164", "country_code", "number
• list_number_regionsList the US state and Canadian province codes that quote_numbers accepts as ``region`` (optional, with ``city``). Returns ``{"regions": [{"country_code", "code", "name"}]}``, such as ``{"country_code": "US", "code": "AZ"
• get_numberFetch one dedicated number by id: its state, capabilities and which agents answer its calls and texts. ``number_id`` comes from ``list_numbers``. Returns the ``PhoneNumberResponse`` as a dict, or ``{"error": "<message>"}
• release_numberRelease a phone number. DESTRUCTIVE and permanent. Calls and texts to the number stop. This month's fee and any earlier months are still billed. There is no refund. The number may not be recoverable. Ask the user before
• get_verification_requirementsRead what the carrier needs to verify the organization before it can buy a number. Call this when quote_numbers shows an offer with ``readiness == "verification_required"``. Read-only. ``country_code`` is ISO alpha-2 (fo
• submit_verificationSend the user's personal or company details and identity documents to the carrier for verification. IRREVERSIBLE: once submitted it cannot be cancelled, and the carrier keeps the documents. ``attest_authorized``: pass tr
• list_verificationsList the organization's carrier verifications, newest first. ``purpose`` is ``number`` or ``sms``; only that kind is listed. Omit to see every registration. ``purpose='sms'`` lists the registrations to text US numbers fr
• get_verificationFetch one verification and its state. Use it to poll. There is no notification, and review takes business days. Poll every few minutes to hours, not every few seconds; the state refreshes from the carrier at most once a
• cancel_verificationCancel a verification that has not been sent for review, or dismiss a rejected one (needed before submitting a new one for the same country and number type). The draft is discarded. Works in state ``awaiting_review`` or
• confirm_verificationWhen a registration shows confirmation 'code', ask the person for the code the carrier texted and submit it here. ``verification_id`` comes from submit_verification or list_verifications. ``code`` is 4 to 10 characters.
• get_agentFetch one saved agent by id. ``agent_id`` comes from ``list_agents`` or ``create_agent``. Returns the ``AgentResponse`` as a dict (``name``, ``system_prompt``, ``first_message``, ``ai_disclosure``, ``voice_config``, ``to
• update_agentChange a saved agent. Safe to repeat: the same call gives the same result. Only the fields you pass change; a field left out keeps its value. ``status`` is ``"live"`` or ``"paused"``; a paused agent does not answer. ``la
• delete_agentDelete a saved agent. DESTRUCTIVE. Ask the user before calling this. Numbers that used the agent stop answering with it: calls ring out and texts reach webhooks only. Reroute them first with ``route_number`` if that matt
• list_contactsList the workspace's contacts: org members (with their phone/email) plus manually saved contacts. Use ``lookup_contact`` for name searches. ``q`` optionally filters server-side (matches name/email/phone). ``limit`` caps
• lookup_contactFind a contact by name, email, or phone fragment. Resolve a person to their ``phone_e164``/``email`` BEFORE calling ``place_call``, ``send_sms``, or ``send_email`` — do not guess a contact's number. Returns up to 10 matc
• list_email_domainsList the addresses this workspace can send email from. Call this BEFORE ``send_email`` when you do not already know the ``from_`` address — do not guess a domain. Returns ``{"items": [...], "next_cursor": ..., "default_f
• whoamiIdentify the human whose credentials this session runs under. Use it to sign or route mail as that person: pass their address as ``send_email(reply_to=...)`` so replies reach them rather than the sending domain, which is
• create_contactSave a new contact for the workspace. Provide at least one of ``phone_e164`` (E.164, e.g. ``+14155551234``) or ``email`` — the API rejects (422) a contact with neither. A duplicate phone or email on an existing contact r

Questions