Send16

Activate an automation. New events matching its triggers will start enrolling contacts. Confirm with the user first: once active it can start emailing contacts straight away.

Add contacts (by ID) to an audience.

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

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.

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

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

Check a registrant in at the door (or undo it). Use the registration ID from list_event_registrations.

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

Create a new audience.

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.

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.

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

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

Delete an Action.

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

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

Delete a contact and all associated events. Irreversible.

Delete a subscription topic. All subscribers will be detached.

Delete an outgoing webhook endpoint.

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.

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.

Manually enroll a contact in an active automation. The automation must be in 'active' status. Use send_event for event-driven enrollment. Confirm with the user first: the automation can start emailing the contact straight away.

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.

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

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

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

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

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

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

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

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

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

Who registered and who came for one event: counts, no-show rate, where people came from (city and state), first-timers vs returning, organisations and registrations over time. Without an eventId, returns insights across every event: regulars and their attendance streaks, cohort retention and the regions growing fastest.

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

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

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

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

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

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). Requires consentConfirmed: true, so confirm with the user that everyone on the list opted in before calling.

List Actions. Actions fire a transactional template when a custom event arrives: simple 'event_name → template' pairings, lighter than full automations.

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

List active and historical enrollments for an automation.

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

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.

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

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.

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

List the people registered for an event, with status (registered, waitlisted, attended, no_show, cancelled), company, city and check-in time.

List the workspace's events (meetups, workshops, conferences) with registered, attended and no-show counts and each event's public registration page.

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