What is Sellbird?
Sellbird, called Harvey until version 0.4.0, runs a B2B outreach pipeline on your own machine. It finds businesses that match your customer (free on OpenStreetMap, or on a paid source that shows its cost first), reads each company's website for buying signals you confirm, finds up to two named owners or managers per company, works out and verifies the email pattern, writes a short sequence for each person and sends it from your Gmail, Microsoft 365 or SMTP mailbox within daily limits and the recipient's office hours. It then reads replies, drafts answers and hands you anything it should not answer alone.
The thinking runs through the Claude Code CLI on a Claude Pro or Max plan, or Codex on a ChatGPT plan, so there is no per-token bill. A local dashboard on 127.0.0.1:5555 shows the Outbox, conversations and contacts. A hosted version at sellbird.ai, with sending domains, inboxes and warmup set up for you, is in early access.
The code is AGPL-3.0 from 0.4.0; releases up to 0.3.x were MIT.
Is Sellbird worth it?
What Sellbird can send matters most, so start there. It sends cold emails and follow-ups, and replies to people who answer, from your own mailbox, under your name. By default every outgoing email waits in an Outbox for you to approve it; autopilot is a switch you turn on yourself. Before anything leaves, a check with no model involved rejects unfilled merge tags, banned phrases, extra links and undeliverable addresses, and only addresses marked deliverable are ever sent to. LinkedIn browser automation exists but is off by default, and the docs say plainly that it breaks LinkedIn's terms and can get the account restricted.
The compliance work goes further than any rival we have read. Every cold email carries an opt-out line and your postal address, and Sellbird warns until the address is set. Any opt-out wording, a bare STOP included, suppresses that person at once and for good. A do-not-contact list is checked as each email leaves, even one you already approved. The docs explain CAN-SPAM, whose penalties they put at up to $53,088 per email, and the GDPR and PECR test of legitimate interest, and an optional Precleared check asks, per recipient, whether consent rules in their country allow a first email. Without a key it allows 10 checks a day; a free key gives 100 a day for 14 days, then 25. If asked whether it is an AI, Sellbird is told to answer truthfully.
The project moves quickly: 5,525 stars, 1,187 forks, v0.4.0 on 6 November 2026 and commits on 11 November. It finds prospects without Apollo, ZoomInfo or Clay, by reading company websites with three HTTP requests each and no model call.
The catch: you are the sender, legally and for deliverability. A new domain needs warmup, a bad list burns a mailbox, and running a sales pipeline on a personal Claude or ChatGPT subscription shares that plan's usage limits with your own work. The hosted service has no public price yet.
Our take: a founder who sends a few dozen careful emails a day and reads the Outbox will get a well-behaved assistant. Someone who wants thousands a day on autopilot wants a different tool, and a different conscience.
Where it earns its place
A founder selling booking software to dental practices
Find practices with no online booking and email the owner
Train Sellbird on your site, confirm the no-online-booking signal, discover practices on OpenStreetMap for free and approve each drafted email in the Outbox. Costs are your Claude plan and a mailbox at about $7 a month.
A two-person agency doing outbound for a UK client
Run a cold campaign without breaching PECR for sole traders
Turn on the Precleared check so each new recipient is cleared before the first email; anything other than ok_to_email is held in the Outbox with the reason shown.
A sales lead who already uses a sequencer
Build a verified prospect list without buying a data tool
Stop the pipeline after verification and run sellbird export for a sequencer-ready CSV, with every address marked verified, risky, guess or invalid.
Before you commit
- Setup
- Python 3.11 or newer, a signed-in Claude Code or Codex CLI and a warmed mailbox; clone the repository, open Claude Code and ask it to set up Sellbird, or pip install, fill in .env and run sellbird train with your website.
- Integrations
- Gmail, Microsoft 365 or SMTP for sending; Instantly for upload; Precleared for consent checks; OpenStreetMap or a paid business search; Docker on Linux.
- Data and privacy
- Config, prospects, conversations and logs stay in a local folder and SQLite database. Prospect details and email text go to Claude or OpenAI through your CLI; Precleared receives recipient address, country and names when the check is on.
- Cost at scale
- Your existing AI plan, one mailbox per sending domain at about $7 a month each on Google Workspace, warmup and any paid search at about $0.37 per 1,000 businesses.
- Limits
- Two contacts per company at most; daily send limits and office hours apply; Precleared's free tier caps checks; Sellbird throttles itself to leave room on your AI plan.
What’s good
- Every email waits for your approval unless you turn on autopilot
- Opt-outs suppressed at once and permanently; do-not-contact list checked at send time
- Optional per-recipient consent check for GDPR, PECR and CASL rules
- No prospecting data subscription: OpenStreetMap search and company websites
- No per-token bill: runs on a Claude or ChatGPT plan
What’s not
- You carry the legal and deliverability risk as the sender
- Shares your personal AI plan's usage limits
- Optional LinkedIn automation breaks LinkedIn's terms
- Hosted version unpriced and invite-only
Best for
Founders and small sales teams selling to local or mid-sized businesses who want researched, personal cold email with a human approving what goes out.
Sellbird: common questions
- Is Sellbird worth it?
- Sellbird is the rare cold email agent that treats the law and the recipient as part of the job, which is why it is worth running and why autopilot is worth leaving off. We rate it 3.9 out of 5.
- How much does Sellbird cost?
- Free under AGPL-3.0. You supply a Claude Pro or Max plan or a ChatGPT plan with Codex, and a mailbox (about $7 a month for Google Workspace). Company search is free on OpenStreetMap or about $0.37 per 1,000 on the cheapest paid source. The hosted sellbird.ai has no published price.
- What are the downsides of Sellbird?
- You carry the legal and deliverability risk as the sender; shares your personal AI plan's usage limits; optional LinkedIn automation breaks LinkedIn's terms; hosted version unpriced and invite-only.
- Who is Sellbird best for?
- Founders and small sales teams selling to local or mid-sized businesses who want researched, personal cold email with a human approving what goes out.
- How much does Sellbird cost for a team or in production?
- Your existing AI plan, one mailbox per sending domain at about $7 a month each on Google Workspace, warmup and any paid search at about $0.37 per 1,000 businesses.
- Is Sellbird safe for company data?
- Config, prospects, conversations and logs stay in a local folder and SQLite database. Prospect details and email text go to Claude or OpenAI through your CLI; Precleared receives recipient address, country and names when the check is on.
Answers checked Nov 14, 2026.