AgentSend

Cold email infrastructure with an HTTP API, for AI agents.

What it is

Tools like Instantly and Smartlead are dashboards built for people. AgentSend is the same infrastructure as an API that an agent can operate end to end: it buys and configures sending domains, creates and warms inboxes, verifies leads, runs sequences, handles replies and keeps a suppression list. A person approves the account once and sets the budget. The agent does the rest.

Every response is written for a program to act on. A request that can't proceed returns the reason and the fix. Anything that waits returns when it will happen next. Anything that costs money can be quoted first with dry_run, and every write accepts an Idempotency-Key, so retries never double-buy or double-send.

The API

POST /v1/signup: Returns a workspace and an API key. Quoting and drafting work immediately. Sending needs the account approved.
POST /v1/infrastructure: Registers sending domains, publishes SPF, DKIM, DMARC and MX, verifies them, and creates inboxes. Credits are held for the quote and only the amount actually bought is charged.
POST /v1/leads, POST /v1/warm-audience: Imports up to 1,000 leads per call and reports duplicates, invalid addresses and suppressed contacts. Warm-audience contacts (customers, partners, past replies) receive a new inbox's first messages.
POST /v1/campaigns, POST /v1/campaigns/{id}/activate: Activation verifies every lead, screens the copy and applies list rules. A rejected campaign comes back with each issue and how to fix it. An accepted one sends a small test batch first and releases the rest after 24 hours without bounces or complaints.
GET /v1/campaigns/{id}/sending-status: One sentence on why the campaign is or isn't sending right now, and when that changes.

curl https://api.useagentsend.com/v1/signup \
  -H 'content-type: application/json' \
  -d '{"principal_email":"you@company.com","org_name":"Acme","agent_name":"acme-sdr"}'

How sending works

New inboxes ramp from 6 to 30 emails a day over roughly two weeks, and the ramp pauses on any bounce or complaint signal. An inbox sends cold email only after the ramp and an inbox-placement check.
Sends follow each inbox's daily cap and the recipient's local business hours. Follow-ups stop when the recipient replies.
A recipient gets at most one cold first message every 72 hours across all AgentSend customers.
Every message carries one-click unsubscribe (RFC 8058) and a postal address. Unsubscribes, hard bounces and complaints are suppressed automatically.
Replies are classified. Out-of-office replies resume the sequence later, and negative replies stop it.
Bounce and complaint rates are tracked per inbox, domain, campaign and workspace. Crossing a threshold pauses that scope and reports why.

Pricing

Prepaid credits. No subscription, plans or seats.

Emails sent	$2 per 1,000
Inbox, warmup included	$4 per month
Sending domain	$15 per year
Lead verification (results reused for 30 days)	$0.01 per lead
Replies, unsubscribes, safety checks, quotes	included

For example, 3 inboxes sending 2,000 emails to 1,000 new leads a month costs about $27.

Status

Early access. Accounts are approved by hand, and the full API reference is in progress. To get access, email george@useagentsend.com.