Sales outreach · checked 2026-10-19Can I vibecode Reply.io?
KINDA· weekend project
A one-person sequencer is small: contacts in SQLite, a step schedule, SMTP sending under a daily cap, reply detection over IMAP and a stop-on-reply rule. An agent builds that in a weekend. What it cannot build is the deliverability layer (warm-up across a pool of monitored mailboxes, bounce and complaint handling, inbox rotation) or the B2B contact database and LinkedIn steps Reply bundles. Cold email from your own mailbox also puts that mailbox and domain at risk when replies are poor or complaints rise.
$59/moprice per seat
$708you'd save a year
weekendbuild time
—people replaced it
What you need on hand.
DifficultyAdvanced · Real infrastructure or OAuth work.
TimeA weekend; DNS and mailbox setup take longer than the code
- 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.
- A separate sending domain and mailboxUse SMTP and IMAP; keep it apart from your main domain so a bad week doesn't hurt normal mail.
- DNS accessSPF, DKIM and DMARC records must pass before the first send.
- A contact list you may lawfully emailCold outreach is regulated in many countries; the README the agent writes should say so.
Before you buildReply has no free plan beyond its 14-day trial. For a few dozen emails a week, a mail merge from your own mailbox may be all you need.
- 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 for one sender to replace Reply.io. Requirements: - Node.js 22 + TypeScript: a Fastify server with Eta pages and a worker loop in the same process. `npm start` serves http://localhost:4850; one admin password in .env (signed cookie). - Storage: better-sqlite3 in ./data/outreach.db: contacts (email, name, company, custom fields as JSON, status), sequences with steps (subject, body, wait days), enrollments (current step, next_send_at), sent messages (Message-ID), events and a suppression list. - Import: a CSV upload with column mapping; drop invalid and duplicate addresses and anything suppressed; require a "lawful basis" note per import and show it in the admin. - Sending: one mailbox through SMTP (nodemailer, settings in .env); a daily cap (default 30), random 90 to 240 seconds between sends, working hours in my time zone (`luxon`), a ramp-up of 5 more emails a day until the cap. Every email gets an unsubscribe link and a List-Unsubscribe header. - Templates: `liquidjs` variables with defaults; a preview for the first three contacts; refuse to send when a variable renders empty. - Replies and bounces: poll the same mailbox over IMAP (`imapflow`) every 2 minutes, match by In-Reply-To, stop that contact's sequence on a reply, pause on an out-of-office, and suppress hard bounces. - Dashboard: sent, replied, bounced and unsubscribed per sequence and step; a reply inbox with a mark-interested button; CSV export of contacts and events. - Single sender. No accounts, no telemetry, local-first. Outbound calls: SMTP and IMAP only. - Out of scope: warm-up networks, mailbox rotation, LinkedIn, calls, SMS, open and click tracking, AI writing, a contact database. - README: SPF, DKIM and DMARC on a separate sending domain, a warning that cold email is regulated (GDPR, PECR, CAN-SPAM) and can get a mailbox suspended, and how to back up the SQLite file.
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 Reply.io.
Add a Reply.io importer to the sequencer in this folder. Requirements: - A command `outreach import-reply <file>` for the "All fields with replies" CSV from People > More > Export to CSV. - Print the columns found, then map Email, First Name, Last Name, Title, Account Name, Status, Opted Out, Sequence and the custom fields before writing anything. - Opted Out and bounced rows go to the suppression list; contacts who replied are stored with their reply text and are not enrolled in anything. - Safe to run twice: skip emails already present. Print a summary of each outcome. - Update the README with the export steps.
Add multiple sender mailboxes to the sequencer in this folder. Requirements: - A mailboxes table with SMTP and IMAP settings, a daily cap and a ramp-up per mailbox. - Pick the mailbox with the most remaining cap for each send, and always reuse the same mailbox for later steps in a thread. - Poll every mailbox for replies and bounces; show per-mailbox sent, bounce and complaint counts, and pause a mailbox when its bounce rate passes 5% in a day. - Update the README.
Add manual task steps to the sequencer in this folder. Requirements: - Step types "LinkedIn task" and "call task" that create an entry in a daily task list with the contact, a note and a link to their LinkedIn URL from the CSV. - Marking a task done advances the sequence; skipping it after 3 days advances it too. - A task list page sorted by due date, with a keyboard shortcut to mark done. - No automated LinkedIn actions of any kind. Update the README.
Add A/B variants to the sequencer in this folder. Requirements: - Any email step can have two variants; new enrollments are assigned 50/50 at random and keep their variant for later steps. - Report sends, replies and reply rate per variant, with a note when fewer than 100 sends per variant make the result unreliable. - A button promotes the winner and sends all future enrollments to it. - Update the README.
What you lose
- Warm-up across a monitored mailbox pool, and rotation over many mailboxes
- LinkedIn, calls and SMS steps in the same sequence
- The live B2B contact database, email verification and intent signals
- Two-way sync with HubSpot, Salesforce, Pipedrive and Close
- The AI SDR that finds leads and handles replies
Why people still pay
Sales teams pay for inbox placement and for not tending it: warm-up, rotation, bounce handling and one inbox run without anyone watching, and the plan bundles other channels and contact data. A DIY sender works until the domain's reputation slips and nobody can say why.
Reply.io or your own copy?
Seats
Over
Your usage
12h ×$/h
Reply.io, 1 yr$708
Your own copy, 1 yr$104running + build session
You keep$605pays for itself in the first month
Estimate · A domain and one mailbox. Reply lists fresh mailboxes at $5 a month and domains from $6 a year, a fair guide to what a DIY sender pays elsewhere. The build is token usage on your agent plan.
Take your data, then cancel.
1 · Take your data out of Reply.io
- 1Contacts: open People, select the contacts, then More > Export to CSV. Choose Basic fields, All fields, All fields with replies, or basic fields with clicks, opens or bounces.
- 2All fields with replies adds Reply Subject, Reply Body, Reply Text Body and Reply Date to every row.
- 3Replies from the Inbox (email and LinkedIn) export to CSV from the Inbox; stats export from the Reports page as contact or sequence CSVs.
- 4We found no export for sequence templates or step text in the help center, so copy those out by hand.
2 · Cancel Reply.io
- 1Open Settings > Plans & Billing and click Cancel my subscription; pick a reason and click Next.
- 2Reply offers to suspend the account on a Data Storage plan for $7 a month if you want to keep your data.
- 3To go ahead, tick all three confirmations (the account can't be restored, data is deleted in 30 days, it is a one-time action) and click Cancel forever.
- 4The subscription then stays active until the end of the billing cycle. On the AI SDR and Agency plans, or when the button isn't shown, contact support by chat or at support@reply.io.
- Reply follows a non-refundable policy, so cancel before the next billing date.
- The account can't be restored, and the data goes 30 days after cancelling: export contacts, replies and stats first.
- Domains bought through Reply are an annual purchase that isn't tied to your subscription; check the expiry on the Email Accounts page. Mailboxes bought there are billed as seats on your plan.
- Keep suppressed and opted-out contacts: the All fields export includes the Opted Out column, and your next tool should start with that list.
The escape hatch
Don't feel like building it? These are already free.
WarmblyOpen sourceApache-2.0 cold email platform with multi-step sequences, a unified inbox, a small CRM and warm-up across mailboxes you own; a young project that needs Postgres and Redis.★ 460 · active Oct 2026 · docker to self-host
WebVisit ↗MauticOpen sourceGPL-3.0 marketing automation with drip campaigns and contact scoring; built for opted-in lists, so cold outreach is a stretch.★ 11k · active Oct 2026 · self-host, real ops
WebVisit ↗DittofeedOpen sourceMIT customer-engagement tool that automates email, SMS and push journeys from user events; aimed at product messaging rather than cold lists.★ 3.0k · active Oct 2026 · docker to self-host
WebVisit ↗
WebVisit ↗MauticOpen sourceGPL-3.0 marketing automation with drip campaigns and contact scoring; built for opted-in lists, so cold outreach is a stretch.★ 11k · active Oct 2026 · self-host, real ops
WebVisit ↗DittofeedOpen sourceMIT customer-engagement tool that automates email, SMS and push journeys from user events; aimed at product messaging rather than cold lists.★ 3.0k · active Oct 2026 · docker to self-host
WebVisit ↗
The numbers
Reply.io pricing
| Plan | Monthly | Annual, per month | What you get |
|---|---|---|---|
| Email Volume | $59/user | $49/user | 1,000 active contacts a month, unlimited emails, mailboxes under a fair-use policy, warm-up, 50 live data credits, 200 website visitor reveals, API and CRM connections. |
| Multichannel | $99/user | $89/user | Unlimited active contacts, 5 mailboxes (10 on annual), one LinkedIn account and calls and SMS included, WhatsApp tasks, team and channel reports. |
| AI SDR (Jason) | $800 | $500 | 1,000 active contacts, 2 LinkedIn accounts, unlimited users and mailboxes, intent signals, AI-written outreach and reply handling. |
| Agency Core | — | $210 | Multiple client workspaces, unlimited clients, users and mailboxes, a consolidated inbox, role-based access and an optional white label. |
- Billing
- Billed monthly or annually; annual saves up to 17% on the email plans and up to 50% on the AI SDR. Email Volume is priced per user up to 5,000 active contacts and per account above that. Reply doesn't refund unused time, so cancel before the next billing date. Annual plans include onboarding with a customer-success manager.
- Hidden costs
- LinkedIn automation is $69 per account a month and calls and SMS $29 on Email Volume. Extra mailboxes need a $29 seat a month each, on top of $5 a month for a fresh mailbox or $15 for a pre-warmed one, plus domains at $6 to $25 a year. AI and live data credits run from $39 for 200 to $599 for 10,000 a month, and email validation from $20 for 5,000.
- Source
- reply.io
Also on the list
Related apps
No standing free plan found: the page offers a 14-day trial of the core features.
Kinda. The core is a weekend build with the prompt on this page, but real gaps remain: Warm-up across a monitored mailbox pool, and rotation over many mailboxes, LinkedIn, calls and SMS steps in the same sequence.
About $59 a month on the Email Volume, 1,000 active contacts plan per seat, $708 a year (checked 2026-10-19).
Warm-up across a monitored mailbox pool, and rotation over many mailboxes; LinkedIn, calls and SMS steps in the same sequence; The live B2B contact database, email verification and intent signals; Two-way sync with HubSpot, Salesforce, Pipedrive and Close; The AI SDR that finds leads and handles replies. If any of those matter to you, keep paying.
Yes: Warmbly (open source), Mautic (open source), Dittofeed (open source).