cancel-email
Cancel a scheduled email before delivery. Only emails with scheduled status can be cancelled.
LABSCO SUMMARY
It is not only a sending API — inboxes, threads and per-agent memory make the receiving side the more distinctive half of it.
Plenty of servers can send an email. What is less usual here is that create-inbox binds an agentId, threads carry labels and an agent assignment, and upsert-agent-memory stores memory against an inbox and a thread — which together is the shape you need for an agent that holds an ongoing conversation by email rather than firing notifications into one. Operational recovery is unusually complete too: list-webhook-event-deliveries returns every attempt with status codes and response times and replay-webhook-event re-delivers, so an event your endpoint dropped is recoverable rather than gone. Read delete-domain before reaching for it — it removes the domain's inboxes, received messages, attachments and sending configuration, and its own description calls the action irreversible.
What it is
An email platform client with 56 tools covering sending domains and scoped API keys, transactional and bulk sending with delivery events, receiving inboxes, messages and threads, namespaces and organisation usage, webhooks with replay, and per-agent memory.
What you get
- Sending: send-email covers HTML and plain text with attachments, labels, custom headers, variables and scheduling; send-bulk-emails takes up to 20 emails in one request with a fallback for values shared across them; cancel-email cancels a scheduled send while it still has scheduled status.
- What became of a send: retrieve-email returns its current delivery status and metadata, retrieve-email-events returns the event history from sent through delivered, opened and bounced, retrieve-email-content returns presigned URLs for the HTML, plain-text and raw MIME source, and retrieve-email-stats returns aggregated daily sending statistics.
- Domains: create-domain adds one for sending, receiving or both; retrieve-domain returns its DNS record configuration with the current verification status of each record; update-domain toggles sending, receiving, open tracking and click tracking; delete-domain permanently removes the domain along with its inboxes, received messages, attachments and sending configuration.
- Receiving as a first-class surface: create-inbox puts an address on a verified domain and can bind an agentId and a namespace, list-messages spans inboxes, retrieve-message returns one with inbox enrichment, retrieve-message-content returns presigned download URLs, and list-message-attachments with retrieve-message-attachment reach the files.
- Conversation handling: reply-to-message with a replyAll flag, forward-message to new recipients, send-inbox-message to start one, update-message for labels, and threads through list-inbox-threads filtered by label, list-thread-messages in chronological order, retrieve-thread which can mark the thread read as it returns, and update-thread whose label changes apply to every message in the thread and which assigns an agent.
- Agent memory tied to the mailbox: retrieve-agent-memory and upsert-agent-memory hold an agent's memory and summary against an inbox and a thread.
- Tenancy and usage: namespaces group inboxes with create, update, list and a delete that refuses while active inboxes remain; retrieve-organization returns plan, region and account status, and retrieve-organization-usage returns daily and monthly sending and receiving against plan limits.
- API keys with real scoping: create-api-key returns the key value once and only once, update-api-key changes the name and permission or restricts the key to specific sending domains, and delete-api-key causes requests using it to be rejected immediately.
- Webhooks including recovery: create-webhook registers an endpoint against event types, update-webhook changes the URL and events or rotates the signing secret, list-webhook-event-deliveries returns every delivery attempt with HTTP status codes and response times, and replay-webhook-event re-delivers one.
Requirements
A Nuntly API key, supplied as NUNTLY_API_KEY, and a domain added and verified before an inbox or a send will work — retrieve-domain returns the DNS records to publish and the verification status of each.
Setup effort
One command plus a key — npx @nuntly/sdk-mcp, then supply credentials
USE CASES
01
Getting a sending domain verified and the first email out
Add the domain, publish the DNS records it returns and re-read the verification status, then send and check the delivery events rather than assuming it landed.
02
Giving an agent an address it can hold a conversation from
Create the inbox bound to the agent, read its threads, reply in place, and keep what the agent learned against the thread it learned it in.
03
Chasing an email a customer says never arrived
Find the send, read its current status, walk the event history for the bounce or the block, and pull the raw source when the content is in question.
04
Recovering events your endpoint dropped during an outage
List recent events, look at every delivery attempt with its status code and timing, and re-deliver the ones that failed.
05
Handing a contractor a key that only touches one domain
Create the key and store the value it returns once, narrow it to the sending domains it should reach, and revoke it the moment it is no longer needed.
06
Sending a batch without one request per recipient
Send up to 20 messages in a single call with shared defaults, read back what was submitted, and check the daily totals afterwards.
56 tools
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
create-api-key
Generate a new API key. The key value is only returned once. Store it securely.
create-domain
Add a domain for sending or receiving emails.
create-inbox
Create a new inbox on a verified domain.
create-namespace
Create a new namespace.
create-webhook
Register an endpoint to start receiving webhook events for your organization.
delete-api-key
Revoke an API key. Requests authenticating with this key will be rejected immediately.
delete-domain
Permanently deletes a domain along with its inboxes, received messages, attachments, and sending configuration. This action is irreversible.
delete-inbox
Soft-delete an inbox.
delete-namespace
Soft-delete a namespace. Rejects if it has active inboxes.
delete-webhook
Remove a webhook endpoint. No further events will be delivered to this URL.
forward-message
Forward a message to new recipients.
list-api-keys
Returns all API keys for the organization. Key values are never included in list responses.
list-domains
Returns all domains with their verification and capability status.
list-emails
Returns sent emails ordered by submission date, newest first.
list-inbox-threads
List threads in an inbox.
list-inboxes
List all inboxes.
list-message-attachments
List all attachments for a message.
list-messages
List all received messages across inboxes.
list-namespace-inboxes
List inboxes in a namespace.
list-namespaces
List all namespaces.
list-organizations
Returns all organizations the authenticated user belongs to.
list-thread-messages
List messages in a thread (chronological order).
list-webhook-event-deliveries
Returns all delivery attempts for a webhook event, including HTTP status codes and response times.
list-webhooks
Returns all registered webhook endpoints for the organization.
list-webhooks-events
Returns recent webhook events across all registered endpoints.
replay-webhook-event
Re-deliver a webhook event to its endpoint. Useful for retrying failed deliveries.
reply-to-message
Reply to a message. Set replyAll to true to reply to all recipients.
retrieve-agent-memory
Retrieve the memory for an AI agent.
retrieve-api-key
Returns API key metadata. The key value is never returned after creation.
retrieve-bulk-emails
Returns the emails submitted in a bulk request.
retrieve-domain
Returns a domain with its DNS record configuration and current verification status for each record.
retrieve-email
Returns an email with its current delivery status and metadata.
retrieve-email-content
Returns presigned URLs to download the HTML, plain-text, and raw MIME source of a sent email.
retrieve-email-events
Returns the delivery event history for an email (sent, delivered, opened, bounced, etc.).
retrieve-email-stats
Returns aggregated daily sending statistics for the current period.
retrieve-inbox
Retrieve an inbox.
retrieve-message
Retrieve a single message with inbox enrichment.
retrieve-message-attachment
Retrieve an attachment with a presigned download URL.
retrieve-message-content
Returns presigned URLs to download the HTML, plain-text, and raw MIME source of a received message.
retrieve-namespace
Retrieve a namespace with inbox stats.
retrieve-organization
Returns the organization's profile, plan, region, and account status.
retrieve-organization-usage
Returns current period usage metrics (daily and monthly) for sending and receiving, against your plan limits.
retrieve-thread
Retrieve a thread. Pass ?markRead=true to automatically remove the unread label from all messages.
retrieve-webhook
Returns a webhook endpoint with its URL, subscribed events, and configuration.
send-bulk-emails
Send up to 20 emails in a single request. Use fallback to set default values shared across all messages.
send-email
Send transactional emails through Nuntly platform. It supports HTML and plain-text emails, attachments, labels, custom headers and scheduling.
send-inbox-message
Send a new message from an inbox.
update-api-key
Update the key name, permissions, or restrict it to specific sending domains.
update-domain
Toggle sending, receiving, open tracking, or click tracking capabilities for a domain.
update-inbox
Update an inbox.
update-message
Update message labels. Only available for messages in user-created inboxes.
update-namespace
Update a namespace.
update-thread
Update thread labels and agent assignment. Label operations apply to all messages in the thread.
update-webhook
Update the endpoint URL, subscribed event types, or rotate the signing secret.
upsert-agent-memory
Create or update the memory for an AI agent.
BEFORE YOU INSTALL
What to know first
Tools you get
56 tools when we connected. The set includes writes such as send-email, create-domain and create-api-key, not only reads.
Requires
- npx on PATH
- Node.js 20 or later
- NUNTLY_API_KEY in your environment
Where it runs
All 3 documented clients run the server on your machine.
CONTEXT COST
Moderate Standing cost
Rated by the size of the 56 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
Connect your client
Server setup
TERMINAL
npx @nuntly/sdk-mcpMCP Clients
Claude Desktop, Claude Code, Cursor
JSON
{
"mcpServers": {
"nuntly": {
"command": "npx",
"args": [
"@nuntly/sdk-mcp"
],
"env": {
"NUNTLY_API_KEY": "<YOUR_NUNTLY_API_KEY>"
}
}
}
}
