The AI first outbound platform for unlimited cold emails and calendar outreaches.
AI reads each prospect's website and writes their message. Replies come back sorted by intent. Every event flows onward through webhooks and n8n to your CRM. All from your own Google Workspace mailboxes, priced per company rather than per inbox.
We built this to run our own outreach.
Tantra started as the internal tool behind our own webinar and cold outreach programs. We needed to send from hundreds of mailboxes without logging into any of them, and we needed the results back in one place. Every capability on this page existed and worked before anyone outside the team could buy it.
AI first, not AI bolted on.
The AI is not a button that rewrites a sentence. It researches each prospect, writes their message, reads the reply, and hands you the ones worth answering. Every outbound motion runs through it by default rather than as an upgrade.
Bring your own AI key
Connect OpenRouter, Cerebras, or Novita. Choose the model and write the system prompt. You pay your provider directly, so there are no credits to buy from us and no markup on inference.
Every message written from their website
Tantra reads each recipient's own site and writes that person's subject line and body from what it finds. This is not a merge tag with a first name dropped into a template.
Replies sorted the moment they arrive
Nine intents including interested, pricing objection, timing objection, referral, and out of office, detected across seven languages. Sequences stop on reply automatically.
Drive it from Claude or Cursor
Tantra ships an MCP server. Point Claude, Claude Code, or Cursor at it and ask in plain language to list campaigns, import contacts, check stats, or launch a send.
Everything a cold email program needs. Nothing metered.
Multi step sequences sent through your own Workspace mailboxes, with the deliverability work handled rather than left to you.
- Sequences with per step delays from same day to a full year
- Sending windows in the recipient timezone, with daily and hourly caps per mailbox
- A/B variants per step, with a winner picked automatically each day
- Address validation and quarantine before a bad list burns a domain
- Mailbox warmup that ramps new senders gradually
- Click tracking on your own domain, suppression, and one click unsubscribe
- Threaded inbox with reply detection, bounce handling, lead stages and scoring
No open tracking. On purpose.
Open pixels hurt deliverability and inflate a number almost nobody acts on. Tantra measures clicks, replies, reply intent, bounces, and unsubscribes instead.
This is timely, we are reviewing vendors this quarter. Can you send pricing?
Interesting, but this is out of budget for us right now.
Not me, but you should talk to our ops lead. Copying her here.
I am out of the office until the 14th with limited access to email.
The one outreach channel with no spam folder.
A calendar invitation is delivered by Google itself and lands on the recipient agenda, not in a promotions tab. RSVP is the engagement signal, so you know who is coming before the day arrives.
- Campaigns up to 50,000 contacts, distributed across your sender pool
- Automatic batching, retry on failure, and expiry once the event passes
- RSVP reconciled every 10 minutes and pushed to your CRM by webhook
- AI written invite descriptions personalized per recipient
- WebinarGeek broadcast and subscriber sync
- UTM tracking and per sender reporting on accept and attendance
We watch your domains so Google does not have to teach you.
Daily domain health scan
Every sending domain checked for SPF, DKIM, DMARC, and DNSBL listings, each scored so you can see a problem forming.
Warmup and rate limiting
New mailboxes ramp gradually. Every send stays under the Gmail ceiling, with your own daily and hourly caps on top.
Clean lists before you send
Syntax, MX, and role address checks run before enrollment. Anything questionable is quarantined rather than sent.
Every event, wherever you need it next.
Tantra emits a typed event the moment something happens. Point it at n8n, Zapier, or Make and take any action from there. We stay the outreach engine, your automation does the rest.
Delivered with automatic retry and deduplication, so a flaky endpoint does not cost you an event. Calendar campaigns POST RSVP updates on their own schedule, with the payload fields you choose.
- Create or update the record in HubSpot, Salesforce, or Pipedrive
- Queue a LinkedIn touch in whichever tool your team uses
- Alert the owner in Slack the moment a reply reads as interested
- Enrich the contact, then push it back into a list
- Append a row to a sheet, or call your own internal service
Those downstream actions run in your automation tool, not inside Tantra. That is the point: you are not limited to the integrations we happened to build.
Connects to what you already run.
Google Workspace
AvailableUpload a service account, have your admin authorize it once, and every mailbox on your domain becomes a sender for email and calendar.
LLM providers
AvailableOpenRouter, Cerebras, and Novita. Your key, your model, your system prompt, billed by your provider rather than by us.
MCP server
AvailableRun Tantra from Claude, Claude Code, or Cursor. Campaigns, contacts, templates, and dashboard metrics as native AI tools.
Webhooks and n8n
AvailableTyped events POST to any endpoint with retry and deduplication. Wire them into n8n, Zapier, or Make to drive your CRM, LinkedIn tooling, or Slack.
WebinarGeek
AvailableSync broadcasts and subscribers, invite registrants automatically, and report on attendance in one place.
REST API and keys
AvailableScoped API keys for headless use, with per scope permissions across campaigns, contacts, and webhooks.
Custom tracking domain
AvailableServe click tracking from your own CNAME so links carry your domain rather than a shared one.
Microsoft Calendar
Coming soonOAuth connection for Outlook calendar users, as an alternative to Google Workspace.
Priced per company. Not per inbox.
Most cold email tools charge for every sending address and every seat. Add twenty mailboxes and you pay twenty times, so the tool gets more expensive exactly as it starts working. Connect as many Workspace mailboxes as you own, import as many contacts as you have, and run both engines on one price.
Three steps to your first send.
Connect your mailboxes
Upload a Google service account and have your Workspace admin authorize it once. Every mailbox on your domain becomes a sender. This is the only step that needs an admin.
Load contacts and build
Import a CSV, then build an email sequence or a calendar event. Choose template copy or let your AI provider write each message from the recipient website.
Launch and watch
Tantra spreads sending across your mailboxes, respects every window and cap, and streams replies, RSVPs, and domain health back to you and your CRM.
Frequently asked questions
Two engines. Your mailboxes. Your AI key.
Start on the free plan and connect your first mailbox today.