Harvey: a Claude Code agent that finds clients and writes them emails
- GitHub stars
- 4K+
- emails per sequence
- 3
- agents inside
- 5
A cold email works when it says something real about the person reading it. Doing that by hand takes hours for a dozen emails. Harvey does it for you: it finds businesses, reads their websites, writes the owner a personal email and works the conversation toward a call. Every email waits for your approval first.
What it is
An open-source sales agent for Claude Code and Codex, with over 4,000 stars on GitHub and an MIT license. You tell it what you sell, it builds your ideal customer profile and proposes what to look for. It finds matching businesses, reads their websites, finds the owner and verifies the email address. It writes a sequence of three short emails, answers the replies and works toward a call. If anyone at a company replies, the rest of the sequence to that company stops.
It runs on your Claude plan through Claude Code, with no separate API bill. Every email lands in the Outbox on its dashboard and waits for you to approve it.
Steps
Step 1. Get a separate sending mailbox
On a separate domain, not your main one: if cold email lands in spam, your real inbox doesn't suffer. It's a paid mailbox: the author recommends Google Workspace, and Microsoft 365 works too.
Step 2. Open Claude Code
You need a Claude Pro or Max plan. Harvey runs on it.
Step 3. Paste the prompt
Claude downloads Harvey, installs what it needs and walks you through setup. Before each install it tells you what it's adding and waits for your OK. If something fails, it tells you what to do.
Step 4. Tell it what you sell
Give Claude your website or answer its questions: what the product is, who it's for, which cities, what it costs. Harvey builds your customer profile from that.
Step 5. Approve the emails
Open the Outbox on the dashboard. Read each email, then approve or reject it. Nothing goes out without your OK.
Paste into Claude Code
Install Harvey, the sales agent, from github.com/ethanplusai/harvey on this computer. Use only the checked version, commit 6b6a23a789090e165802baef4104ee4618a3e169: download exactly that commit into a new folder, not main or any other version. First read the README and CLAUDE.md in that folder and tell me in plain words what you'll install and run. Then walk me through the setup in CLAUDE.md, one step at a time. It needs Python 3.11 or newer: if I don't have it, install it for my system. Before each install, tell me in plain words what you'll install and with which command, and wait for my OK. Don't install the LinkedIn browser and don't turn LinkedIn on. Connect only a separate sending mailbox on a separate domain, never my main one: tell me how to set it up and connect it. Tell me where to get a free email verification key (Reoon, ZeroBounce or Hunter), and add the keys to the config in that folder when I send them. Then train Harvey on my product: use my website or ask me what I sell, to whom, in which cities and what it costs. Keep approval mode on and don't turn on autopilot: no email goes out without my OK. To start, set at most 10 emails a day and set the mailbox warmup start date, so Harvey raises the limit slowly. Show me how to open the dashboard and where to approve emails. If something won't install, explain why and fix it. I'm not a developer: do everything you can yourself.
Want this working for your business?
- AI agents for your business
- Automations for the work you repeat
- 1:1 consulting calls
Good to know
Warm up the mailbox first
A new mailbox that starts sending cold email right away ends up in spam. The author recommends warming it for 2-4 weeks (he suggests TrulyInbox) and starting at 10-20 emails a day. Harvey can raise the limit for you, a little each day.
Read the first emails
Approve the first batches by hand and see how Harvey writes. Don't like the tone or the angle? Tell Claude what to change.
Finding businesses can cost nothing
By default Harvey searches OpenStreetMap: free, no account needed. It has few businesses without a storefront. Paid sources are a separate opt-in, and Harvey shows the price before any spend.
The honest read
- These are real emails to real people. Start with a small list and read every email before you approve it.
- Legally, you are the sender. Every cold email ends with an opt-out line, and Harvey stops emailing anyone who opts out. Some countries, Germany for example, want consent even for business email.
- Without an email verification key, the addresses it finds stay unverified, and Harvey doesn't send to them. Reoon's free key covers 600 checks a month.
- Harvey uses your Claude plan's limits but leaves headroom for your own work. LinkedIn is off by default: automating it breaks LinkedIn's rules and can get the account restricted.
Want this built for your business?
I build AI agents and automations for businesses, and do 1:1 consulting calls. Message me on Instagram with what your business does, and I'll tell you what can be automated.
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