Sales outreach · checked 2026-10-13Can I vibecode Instantly?
KINDA· weekend project
The sending engine is the easy part: rotate a few mailboxes under daily caps, follow up in the same thread, stop when someone replies and keep a suppression list. An agent writes that in a sitting with nodemailer and an IMAP client. What Instantly adds is the warmup network, a large pool of real inboxes that open and rescue each other's mail, plus a lead database and deliverability tooling, and none of that exists on day one of a home-built tool. You also inherit the fiddly parts yourself: Google and Microsoft sign-in rules, DNS records and keeping new domains out of spam.
$47/moprice
$564you'd save a year
weekendbuild time
—people replaced it
What you need on hand.
DifficultyIntermediate · Some system setup or keys.
TimeAn afternoon for the sequencer; new domains still need weeks of gentle sending
- Claude Code, Codex or CursorAny of them can run the prompt.
- Node.js 22better-sqlite3 compiles a native module, so build tools must be installed.
- Mailboxes on domains you ownUse a separate domain for cold mail so your main domain's reputation stays safe.
- DNS access for those domainsTo add SPF, DKIM and DMARC records before the first send.
- App passwords or OAuthGmail gives app passwords only with 2-step verification on; Microsoft 365 is phasing out password sign-in for SMTP, so plan on OAuth there.
Before you buildInstantly has no free plan, only a 14-day trial. If you send a few dozen emails a day from one or two mailboxes, a self-built sequencer covers it.
- 1. Install one agent: Claude Code, Codex, Cursor.
- 2. Make an empty folder and open it in the agent.
- 3. Paste the prompt below, press enter, and answer its questions as it builds.
The prompt
Build me a cold email sequencer to replace Instantly, sending from mailboxes I
already own. Requirements:
- Node.js 22 + TypeScript: a worker process plus a Fastify page on
http://127.0.0.1:4800. Data in better-sqlite3 at ./data/outreach.db.
- Mailboxes in ./mailboxes.yaml (SMTP and IMAP settings), passwords in .env.
Per mailbox: a daily cap (default 30), a random 3-8 minute gap between sends
and a sending window, Mon-Fri 9:00-17:00 in my time zone.
- Campaigns: import leads from CSV with papaparse (email plus any columns as
variables), up to 5 steps with a delay in days each, {{first_name}} variables
and {option a|option b} spintax. Plain-text emails.
- Send with nodemailer, rotating mailboxes; follow-ups go from the same mailbox
in the same thread (In-Reply-To and References headers).
- Every 5 minutes, read each INBOX with imapflow + mailparser: a reply stops
that lead's sequence, a bounce marks the lead bounced, out-of-office does not.
- Every email carries a one-line opt-out and a List-Unsubscribe header; a global
suppression list is checked before each send.
- One inbox page with all replies across mailboxes, tagged by campaign; mark
each lead interested, not interested or later.
- Before a campaign starts, look up SPF and DMARC for each sending domain (and
DKIM for the selector I set) and refuse to send if SPF or DMARC is missing.
- Stats per campaign and step: sent, replied, bounced, unsubscribed. No
open-tracking pixel.
- No accounts, no telemetry, local-first.
- Out of scope: a warmup network, a lead database, buying domains or mailboxes.
- README: app passwords versus OAuth (budget an hour for Google or Microsoft
OAuth), safe daily volumes for new domains, CAN-SPAM and GDPR basics.Opens your agent with the prompt filled in, you press enter. Or copy it and paste it into an empty folder.
Then keep going
Next prompts, same folder.
The first prompt builds the core. Run these one at a time in the same folder to grow it into your own Instantly.
Add a private warmup mode to the sequencer in this folder. Requirements: - Only between mailboxes listed in ./mailboxes.yaml; never with outside addresses. - Each day, every warmup mailbox sends short, varied plain-text messages to the others, ramping from 2 to 20 a day over four weeks. - Over IMAP, recipients find these messages (tagged with a header), move them from spam to the inbox, mark them read and reply to about a third. - A page shows per mailbox: sent, landed in spam, rescued. - Out of scope: joining any shared warmup pool. - Update the README with what this can and can't do for reputation.
Add AI first lines to the sequencer in this folder. Requirements: - For each lead with a website column, fetch the homepage text with undici + cheerio and ask Claude (ANTHROPIC_API_KEY in .env) for one opening sentence under 25 words that mentions something specific from the page. - Store it as the {{first_line}} variable; leads without a site get none. - A review screen lists every generated line with approve, edit and reject; nothing unapproved is ever sent. - Update the README with the cost per 100 leads.Add an importer for Instantly's All Leads CSV export to the sequencer in this folder. Requirements: - Read the header row first, show the column mapping (email, variables, lead status, interest status, last contacted) and ask before importing. - Leads marked bounced, unsubscribed or not interested go straight to the suppression list. - Keep custom columns as variables for templates. - Running it twice must not create duplicates. - Update the README with the export steps.
What you lose
- The warmup network that builds sender reputation
- A 450M+ contact lead database with enrichment
- Done-for-you domains and pre-warmed mailboxes
- Inbox placement tests and deliverability alerts
- AI reply handling, the CRM and shared team workspaces
Why people still pay
Agencies and founders pay because one flat price covers unlimited mailboxes and warmup, which is how high-volume cold email stays out of spam. Leads, sending and replies sit in one tool, so a campaign goes from list to launch in an afternoon. Complaints are about deliverability that looks healthy in the dashboard but not in real inboxes, separate subscriptions per product and charges after a missed cancellation.
Instantly or your own copy?
Over
Your usage
12h ×$/h
Instantly, 1 yr$564
Your own copy, 1 yr$38running + build session
You keep$527pays for itself in the first month
Estimate · The software costs nothing to run; a small VPS keeps the worker sending when your laptop sleeps. Domains and mailboxes cost the same with or without Instantly, unless you used its done-for-you accounts. The build is token usage on your agent plan.
Take your data, then cancel.
1 · Take your data out of Instantly
- 1Leads: open Leads > All Leads, select all, then Row actions > Download selected. The CSV has lead data, variables, status, interest and verification.
- 2Campaign numbers: open a campaign > Analytics > the three dots > Download Analytics. The Activity section on the same tab downloads the full send log as CSV.
- 3Sequence copy and Unibox replies have no file export; pull them through the API (get campaign, get email) or copy them by hand.
- 4Do it before the subscription ends: without an active plan the dashboard and exports are gone.
2 · Cancel Instantly
- 1Go to Settings > Billing & Usage.
- 2On each tab (Outbound, Data Credits, Add-ons) click Cancel Plan and confirm; each product is cancelled separately.
- 3Done-for-you, Airmail and pre-warmed mailboxes are cancelled under Email Accounts & Domains.
- 4Check that every tab now says Cancels on [date], not Renews on.
- Outbound and credit plans run to the end of the cycle; CRM and Inbox Placement stop immediately.
- Cancelling done-for-you accounts takes effect at once, and their Unibox conversations are deleted after 24 hours.
- There is no pause, and a renewal that has already gone through is still charged, so cancel before the renewal date.
- A domain bought through Instantly expires a year after purchase, or earlier once all its mailboxes are cancelled.
The escape hatch
Don't feel like building it? These are already free.
WarmblyOpen sourceSelf-hosted cold email platform with sequences, a unified inbox, a small CRM and warmup across your own mailboxes; runs on Docker Compose. Young project, started in 2026.★ 425 · active Oct 2026 · docker to self-host
WebVisit ↗Email-automationOpen sourceA small Django app for templated emails with scheduled follow-ups; no warmup or mailbox rotation. AGPL with extra clauses.★ 179 · active Aug 2026 · self-host, real ops
WebVisit ↗MauticOpen sourceOpen-source marketing automation with drip campaigns and contact scoring. Built for opt-in lists, so cold outreach is a stretch.★ 11k · active Oct 2026 · self-host, real ops
WebVisit ↗
WebVisit ↗Email-automationOpen sourceA small Django app for templated emails with scheduled follow-ups; no warmup or mailbox rotation. AGPL with extra clauses.★ 179 · active Aug 2026 · self-host, real ops
WebVisit ↗MauticOpen sourceOpen-source marketing automation with drip campaigns and contact scoring. Built for opt-in lists, so cold outreach is a stretch.★ 11k · active Oct 2026 · self-host, real ops
WebVisit ↗
The numbers
Instantly pricing
| Plan | Monthly | Annual, per month | What you get |
|---|---|---|---|
| Growth | $47/workspace | $37.60/workspace | Unlimited email accounts and warmup, 1,000 uploaded contacts, 5,000 emails a month, chat support. |
| Hypergrowth | $97/workspace | $77.60/workspace | 25,000 uploaded contacts, 125,000 emails a month, premium live support. |
| Light Speed | $358/workspace | $286.30/workspace | 100,000 uploaded contacts, 500,000 emails a month, extra deliverability features. |
| Enterprise | custom | — | Above 500,000 emails and 100,000 contacts, private deliverability network. |
| Growth Credits (lead database) | $47/workspace | $37.60/workspace | 1,500 to 2,000 credits a month for the 450M+ contact database and enrichment. |
- Free tier
- No free plan. A 14-day trial without a card: 2 email accounts, 250 leads in campaigns, 1,000 emails and 100 credits.
- Billing
- Monthly or yearly (about 20% off). Outreach, credits, CRM and other products are separate subscriptions, each billed and cancelled on its own.
- Hidden costs
- The lead database needs its own credit plan. Done-for-you domains, pre-warmed mailboxes, inbox placement tests and the CRM cost extra. There is no pause, plans you forget to cancel keep renewing, and once the subscription lapses the dashboard and exports are gone.
- Source
- instantly.ai
Also on the list
Related apps
Kinda. The core is a weekend build with the prompt on this page, but real gaps remain: The warmup network that builds sender reputation, A 450M+ contact lead database with enrichment.
About $47 a month on the Growth (Outreach) plan, $564 a year (checked 2026-10-13).
The warmup network that builds sender reputation; A 450M+ contact lead database with enrichment; Done-for-you domains and pre-warmed mailboxes; Inbox placement tests and deliverability alerts; AI reply handling, the CRM and shared team workspaces. If any of those matter to you, keep paying.
Yes: Warmbly (open source), Email-automation (open source), Mautic (open source).