Send16 MCP Server

by spruikco Your server? Claim it

answering

Send16 MCP is answering right now. Last checked 5 min ago. 51 installs a week from npm. It exposes 79 tools. Last commit 19 Jul 2026.

Email for AI agents: send mail, manage contacts, automations & webhooks. Zero-DNS first send.

Installs per day peak 1 213 · avg 66 · +96% w/w

a month agotoday

Uptime history 47 days of history · worst day 0%

47 days agonow

100.0%

Uptime 24h

92 of 92 checks

Tools

read from the server

179 ms

Response time

average over 24h

Installs / week

npm and PyPI

Nothing serious here today

Today is the operative word: we check Send16 MCP every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 5 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add send16-mcp --transport http https://mcp.send16.com/mcp

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "send16-mcp": {
      "url": "https://mcp.send16.com/mcp"
    }
  }
}

~/.codex/config.toml

[mcp_servers.send16-mcp]
url = "https://mcp.send16.com/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "send16-mcp": {
      "url": "https://mcp.send16.com/mcp"
    }
  }
}

.vscode/mcp.json

{
  "mcpServers": {
    "send16-mcp": {
      "url": "https://mcp.send16.com/mcp"
    }
  }
}

This one needs environment variables set before it will start: SEND16_API_KEY (Your Send16 API key (sk_live_...), from https://send16.com/dashboard/developers). The author declared them in the registry entry; get the values from the project itself.

Available tools 79

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

contact

create_contact

Add a single new contact, optionally straight into audiences and/or with tags — e.g. 'add this person from my email into the newsletter list'. Contacts are subscribed by default. For more than a handful of people, use import_contacts instead.

delete_contact

Delete a contact and all associated events. Irreversible.

get_contact_health_score

Get a contact's 0-100 health score based on recent engagement (opens, clicks, replies).

get_contact_timeline

Get a contact's full activity timeline: emails received, events fired, opens, clicks, automation enrollments, topic changes.

remove_contact_from_audience

Remove a contact from an audience.

update_contact

Update a contact's profile fields, custom fields, or subscription state.

send

send_broadcast

One-shot broadcast: create a campaign and immediately schedule it to send, in a single call. Pass either an audienceId, segmentId, topicId, or fully-qualified filter. Provide html OR templateSlug.

send_campaign_test

Send a test email for an existing campaign to preview how it will look in recipients' inboxes.

send_email

Send a transactional email through Send16. Provide `html`, `text`, or both (text-only is fine for OTPs/receipts/alerts). `from_email` must belong to a domain that is verified in the workspace — call `whoami` for the account and `list_domains` to see which senders are allowed; a send from an unverified domain returns a clear error, not a silent failure. For a zero-setup first send, use from_email `[email protected]` — the sandbox sender delivers with no DNS, but only to your own account email.

send_event

Fire a custom event for a contact. Automations whose trigger is `{type:'custom_event', eventName:'<name>'}` will enroll the contact and start running. Payload is exposed to condition steps as `event.<key>`.

send_reply

Reply to an inbox conversation. The reply is sent from the original recipient address (the alias the convo arrived on) and threaded back to the contact.

action

create_action

Create an Action that maps an event name to a transactional template. Each matching event sends one email to the contact.

delete_action

Delete an Action.

get_action

Get a single Action with its trigger config and template binding.

update_action

Update an Action (toggle enabled, change template, change event name).

campaign

create_campaign

Create a new email campaign as a draft: optionally with full HTML content and recipients (exactly ONE of audienceIds / segmentId / contactIds / tagIds / sendToAll) so it's ready to test and send. Nothing is sent until schedule_campaign.

delete_campaign

Delete a draft campaign. Sent campaigns cannot be deleted (only archived).

get_campaign_stats

Get detailed performance statistics for a specific campaign including open rate, click rate, bounce rate, and delivery metrics.

update_campaign

Update a draft campaign: name, subject, preview text, sender info, HTML content, and/or recipients. Retarget with exactly ONE of audienceIds / segmentId / contactIds / tagIds / sendToAll, then verify with preview_campaign_recipients before sending. Only drafts can be edited.

automation

get_automation

Get a single automation by ID, including its trigger, steps, and current status.

get_automation_stats

Get aggregate analytics for an automation: total enrollments, completed, exited, open/click rates per step.

list_automation_enrollments

List active and historical enrollments for an automation.

contacts

add_contacts_to_audience

Add contacts (by ID) to an audience.

list_contacts

List all contacts with optional filtering by subscription status and tag. Supports pagination.

search_contacts

Search contacts by email address or name. Returns matching contacts with their tags and subscription status.

convo

add_convo_note

Add a private internal note on a conversation. Notes are visible only to workspace members.

get_convo

Get a single conversation with its full thread of posts (incoming + outgoing).

update_convo

Update conversation status (open/closed/archived/snoozed) or assignee.

topic

create_topic

Create a new subscription topic. Contacts opt into topics individually via the preference center.

delete_topic

Delete a subscription topic. All subscribers will be detached.

update_topic

Update a subscription topic (name, description, default).

audience

create_audience

Create a new audience.

delete_audience

Delete an audience (list). Contacts are not deleted — only the list and its memberships are removed.

brand

get_brand

Get the workspace's brand settings: colors, logo, fonts, and the DESIGN.md spec injected into AI generation prompts.

update_brand

Update workspace brand settings. The designSpec field is a Markdown DESIGN.md document fed into AI generation system prompts — use it to encode voice, do/don't lists, and visual rules.

domain

add_domain

Register a new sending domain. Returns the DNS records the user must add to their DNS provider, after which they should call check_domain_health to verify.

check_domain_health

Check the DNS health of a specific domain, including DKIM, SPF, DMARC, and MX record verification status. Triggers a fresh DNS lookup.

message

get_message

Fetch a single message with its full event timeline (created → sent → delivered → opened → clicked → ...).

get_message_events

Get just the delivery event timeline for a message — no body or recipient details.

pause

pause_automation

Pause an automation. Existing enrollments freeze in place; no new contacts enroll.

pause_campaign

Pause a sending campaign. Already-sent messages are unaffected; remaining sends halt.

preview

preview_campaign_recipients

Preview the recipient set for a campaign before sending. Returns count + sample list.

preview_segment

Preview the contacts that match a segment without sending.

suppression

add_suppression

Add an email to the suppression list. Future sends to this address will be blocked.

remove_suppression

Remove an email from the suppression list. Use only when you've confirmed the recipient wants to receive mail again.

webhook

create_webhook

Register an outgoing webhook endpoint. Send16 POSTs event JSON to this URL with an HMAC-SHA256 signature. Outgoing webhooks are a plan feature.

delete_webhook

Delete an outgoing webhook endpoint.

workspace

get_workspace

Get the current workspace (the one the API key belongs to).

get_workspace_usage

Get the current month's send count, contact count, and plan limits.

actions

list_actions

List Actions. Actions fire a transactional template when a custom event arrives — Plunk-style 'event_name → template' pairings, simpler than full automations.

activate

activate_automation

Activate an automation. New events matching its triggers will start enrolling contacts.

audiences

list_audiences

List audiences (lists). An audience is a static, manually-managed group of contacts.

automations

list_automations

List all automations in the workspace, including draft/active/paused status and trigger types.

campaigns

list_campaigns

List email campaigns, newest first. Use `search` to find a past campaign the user describes vaguely ('the invite one', 'that July newsletter') — it matches name and subject case-insensitively; try distinctive words from their description and broaden if no hits.

convos

list_convos

List inbox conversations. Filter by state, mailbox, label, screener status, or full-text search. Send16's unified inbox combines transactional reply threading with team-managed shared inboxes.

deliverability

get_deliverability_status

Get your workspace's deliverability summary — sending reputation, domain authentication status, and recent bounce/complaint health. (Deliverability Hub plan feature.)

design

design_email_template

Use AI to generate a complete email HTML template based on a description. Returns ready-to-use HTML that can be sent or used in campaigns.

domains

list_domains

List all sending domains configured in your Send16 workspace, including their verification status and DNS records.

duplicate

duplicate_campaign

Duplicate a campaign (template, content, and settings) as a new draft — works on sent campaigns too, so this is the way to re-use a past campaign's design. Optionally rename and retarget in the same call (exactly ONE of audienceIds / segmentId / contactIds / tagIds / sendToAll). NOTE: without retargeting, the copy keeps the ORIGINAL campaign's recipients.

enroll

enroll_in_automation

Manually enroll a contact in an active automation. The automation must be in 'active' status. Use send_event for event-driven enrollment.

generate

generate_email_from_url

Scrape a URL (e.g. a launch blog post or product page) and generate an email draft from its content. Returns subject, preview text, and HTML body.

import

import_contacts

Bulk import contacts from CSV data (min column: email), optionally straight into audiences and/or with tags. This is the tool for cross-app flows — e.g. pulling people out of Gmail, a CRM, or a spreadsheet and landing them in a Send16 audience in one call. Set updateExisting for upsert semantics (safe to re-run).

inbox

list_inbox_counts

Get unread/total counts per category and label for the inbox sidebar (newsletter, transactional, marketing, calendar, social, cold).

mark

mark_convo_read

Mark a conversation as read for the current viewer.

messages

list_messages

List messages from the unified send log (transactional + campaign). Filter by recipient, sender, status, date range, or source.

pre

pre_send_review

Run an AI pre-send review on an email's HTML before sending. Surfaces tone issues, broken links, missing alt text, spam triggers, and accessibility problems.

regenerate

regenerate_webhook_secret

Rotate the HMAC signing secret for an outgoing webhook endpoint. Returns the new secret once.

render

render_email_content

Compile an EmailContent JSON object (the shape used by the Send16 builder + templates) into HTML using the platform's authoritative renderer. Returns the exact HTML the API would send. Useful for previews and post-processing.

resume

resume_campaign

Resume a paused campaign.

schedule

schedule_campaign

Schedule (or send immediately) an existing draft campaign to an audience/segment/topic.

screener

screener_decide

Decide a pending screener conversation (first-time sender). 'allow' lets future emails through, 'reject' blocks, 'cold' marks as cold outreach.

segments

list_segments

List dynamic segments. Segments compute their members from a filter expression at send time.

suppressions

list_suppressions

List suppressed email addresses (bounces, complaints, unsubscribes, manual).

template

get_template

Get a single starter template by ID, including its EmailContent JSON.

templates

list_templates

List starter-gallery email templates available to every workspace.

topics

list_topics

List subscription topics. Topics are granular categories contacts can subscribe to (e.g. 'product-updates', 'weekly-digest'). Campaigns and automations can be gated to subscribers of a specific topic.

webhooks

list_webhooks

List configured outgoing webhooks (your endpoints that Send16 POSTs delivery events to). Outgoing webhooks are a plan feature.

whoami

whoami

Verify the API key and return the authenticated workspace: name, plan, email quota (used/limit), and owner. Call this first to confirm the key works before sending. Pair with list_domains to see which `from` addresses are allowed.

workspaces

list_workspaces

List workspaces the authenticated user has access to (owner or member).

Endpoints

URL	Transport	State	Latency	Checked
https://mcp.send16.com/mcp	streamable-http	answering	180 ms	5 min ago

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Send16 MCP — questions

Answers built from our own checks of this server.

What can Send16 MCP do?

It exposes 79 tools, read directly from the server on our last check. Among them: activate_automation, add_contacts_to_audience, add_convo_note, add_domain, add_suppression, check_domain_health and 73 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

What is Send16 MCP mostly used for?

Its tools cluster around contact, send and campaign. That is what this server is built to work with — the grouping comes from the actual tool names, not from a category we assigned.

Is Send16 MCP working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 92 of 92 checks got a reply (100.0%), average response time 179 ms. The bar chart above shows every period we have measured.

How do I connect Send16 MCP?

Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Send16 MCP need an API key?

No. Send16 MCP completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 79 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is Send16 MCP?

It answers our handshake in 179 ms on average, which is faster than 70% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.

How many people use Send16 MCP?

The npm package send16-mcp was installed 51 times in the last week. Week over week that is +96%. We show installs rather than GitHub stars on purpose: a star is a bookmark, an install is someone actually running it.

Is Send16 MCP open source?

Yes — it is published under the MIT licence, written in JavaScript and 0 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.