Splee

Paste your website. Splee finds your buyers, writes each one a personal cold email, sends it from your own mailbox and answers the replies.

Watch it in full quality (mp4)

Overview. Replies, meetings and the cost of each hot lead.	Inbox. Every hot reply gets an answer drafted.
Campaigns. Find companies, find people, write, send.	Leads. Every decision maker and where they stand.

_{The screenshots show Fieldnote, a made-up company with made-up leads.}

Splee is a self-hosted AI outbound agent, modelled on explee.com. You paste your website. A Claude agent then researches your company, competitors and buyer segments, and finds matching companies and their decision makers on the web. It writes a personal cold email to each person and sends them from your own mailboxes within a daily email limit. It also reads the replies over IMAP and answers interested leads with your booking link.

It runs on your machine or server, with your own Claude subscription and mailboxes. Nothing goes through a third-party outbound platform.

Features

• Research. It profiles your company, maps competitors, proposes buyer segments as campaigns, finds companies and decision makers, and writes personal emails and LinkedIn sequences. Every run streams its progress live and can be cancelled.
• Sending. It sends from any SMTP mailbox, rotating mailboxes under per-mailbox daily limits, and each mailbox can use its own signature and booking link. Sending respects each project's time zone, send days and hours. Follow-ups thread under the first email. You can choose to review every draft or approve whole campaigns.
• Inbox. It polls IMAP for replies and sorts them into hot, question, not interested, out of office, unsubscribe or bounce. It drafts replies with your booking link and either sends them or holds them for approval. Saved replies drop your usual answers into a reply, with the lead's name and company filled in.
• Safety rails. It keeps a suppression list of emails and domains, adds an unsubscribe link and List-Unsubscribe header to every outreach email, and handles bounces. A daily email limit per project and per mailbox caps sending, a mailbox that bounces more than 1 in 10 of its leads pauses itself, and the DNS checker covers MX, SPF, DMARC and DKIM. With a NeverBounce, MillionVerifier, Hunter, Kickbox, Bouncer, Emailable, Clearout, Reoon, DeBounce, EmailListVerify, Bouncify, QuickEmailVerification, Abstract API, MailboxValidator or MyEmailVerifier key, each address is checked before its first email, and ones that don't exist fail instead of bouncing. Hunter, Findymail, Prospeo, Anymail Finder, LeadMagic, Apollo, Voila Norbert or Skrapp can look up the real address for a guessed one.
• Costs. Spend and cost per hot lead add up what Claude Code reports for each agent run and the cost per email you set on each mailbox. On a Claude subscription, the AI part is the equivalent API price.
• Integrations. Hot-lead alerts go out by email or to a Slack, Discord, Microsoft Teams, Google Chat, Telegram, Lark, Feishu, DingTalk, WeCom, Webex, Mattermost, Rocket.Chat, Zulip, Zoho Cliq, Pumble or Flock channel, or as a phone notification through ntfy, Pushover, Gotify or Bark, which also hear about booked meetings and reminders that come due. Calendly, Cal.com, SavvyCal, OnceHub, Zcal, TidyCal, Appointlet and Chili Piper bookings mark the lead Meeting booked on their own, and inbox reminders show up in Google Calendar, Outlook or Apple Calendar through a private feed. Tally, Typeform, Fillout, Jotform, Paperform, Formbricks, Netlify and Webflow forms add whoever fills them in as a lead. Hot and booked leads go into HubSpot, Pipedrive, Attio, Close, folk, Capsule, Brevo, Zendesk Sell, Less Annoying CRM, Salesflare, Affinity, Freshsales, Copper, Insightly, Twenty, a Notion database, an Airtable table, a Baserow, NocoDB or Grist table, or a self-hosted Twenty, EspoCRM or Odoo, with a note holding their reply, and a BCC address copies every email Splee sends to any CRM that logs email that way. With Unipile connected, LinkedIn sequences send themselves from your own LinkedIn account. Webhooks to up to 10 endpoints can also get every reply, booked meeting, unsubscribe, bounce, sent email and due follow-up. The Integrations page lists recent deliveries and can resend one. Leads import from CSV or Excel, from a Google Sheet's link, from an Airtable table, from a Notion database, from a Baserow, NocoDB or Grist table or from Hunter's list of people at a company, and export to CSV. A public REST API takes API keys.
• Teams. It has organizations, invites and admin roles.

Quick start

You need:

• Docker, for Postgres.
• Rust 1.93 or newer.
• Node.js 20 or newer and pnpm.
• The Claude Code CLI, signed in. Running claude in your shell must work.

From the repo root, run each of these in its own terminal:

docker compose up -d                                  # Postgres on 127.0.0.1:55432 (dev password, loopback only)
(cd backend && cp -n .env.example .env && cargo run)  # API on 127.0.0.1:8787, runs migrations on start
(cd frontend && pnpm install && pnpm dev)             # app on http://localhost:3333

Open http://localhost:3333, sign up and paste a website. The first account in an organization is its owner.

Configuration

The backend reads backend/.env, and the frontend reads its own environment.

Variable	Default	What it does
DATABASE_URL	required	Postgres connection string.
APP_SECRET	required	Encrypts mailbox passwords. Set a long random value (openssl rand -hex 32) before you connect a real mailbox, and keep it, because changing it makes the saved passwords unreadable. With an https:// PUBLIC_URL the API won't start on the example value or anything shorter than 32 characters.
PUBLIC_URL	http://localhost:3333	Where the app is served. Used for unsubscribe, invite and inbox links in emails. An https:// URL also makes the sign-in cookie HTTPS-only.
BIND_ADDR	127.0.0.1:8787	Address the API listens on.
AGENT_MODEL	claude-sonnet-5-5	Claude model for every agent run.
AGENT_CONCURRENCY	2	How many agent runs execute at once.
SENDING_ENABLED	true	false stops the sender, so approved emails, follow-ups and auto-replies wait. IMAP polling, agent runs and notification emails to your team still run.
OPEN_SIGNUP	true	false makes sign-up invite-only once the first account exists. Every account can run agents on your Claude subscription, so turn this off on a public server.
PUBLIC_AGENT	true	false turns off the home page demo, the company explorer and the support chat for signed-out visitors, which otherwise run the agent on your Claude subscription within hourly limits per visitor.
BIRD_BIN	unset	Path to the bird CLI (npm i -g @steipete/bird). When set, research runs can search and read X.
RUST_LOG	unset	Log filter, e.g. splee=debug,tower_http=info.
API_URL (frontend, build time)	http://127.0.0.1:8787	Where the Next.js server proxies /api/*. next build bakes it in, so set it when you build, not when you start.
NEXT_PUBLIC_SOURCE_URL (frontend, build time)	https://github.com/Iweisc/splee	Where the "Source code" links in the footer and sidebar point. If you run a modified version for other people, the AGPL requires you to point this at your source.

bird reads X with the cookies of a browser that is logged into x.com, so the agent sees X as that account. Pick the browser in ~/.config/bird/config.json5.

Running it for real

The quick start is for your own machine. To run Splee for a team:

1. Postgres. Use a database with its own strong password. The compose file's password is public and only meant for local development.
2. Backend. Build it with (cd backend && cargo build --release) and start it with (cd backend && ./target/release/splee) as a user whose claude CLI is signed in. It reads .env from the directory it starts in and applies migrations on start. Set DATABASE_URL to that database, PUBLIC_URL to the https:// address people will use and APP_SECRET to the output of openssl rand -hex 32. With an https:// PUBLIC_URL the API refuses the example secret and makes the sign-in cookie HTTPS-only. Set OPEN_SIGNUP=false too, so the first account can still sign up and everyone after it needs an invite, and PUBLIC_AGENT=false unless you want strangers to try the demo. Keep BIND_ADDR on loopback or a private network, because browsers only need to reach the frontend.
3. Frontend. Build it with API_URL pointing at the backend, (cd frontend && pnpm install && API_URL=http://127.0.0.1:8787 pnpm build), then start it with (cd frontend && pnpm start) on port 3333.
4. HTTPS. Put a reverse proxy such as Caddy or nginx in front of port 3333 for PUBLIC_URL's host. Only the frontend needs to be public, because it proxies /api/* to the backend. The proxy must set X-Forwarded-For, because the hourly limits on the public demo, explorer and support chat count each visitor by its last entry. Caddy does this by default, and nginx needs proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;. Without it, visitors can pick their own address and run up your Claude usage.
5. Monitoring. Point an uptime monitor at https://<your host>/api/health. It returns 200 when the frontend, the backend and Postgres all answer.
6. Backups. Back up the database and keep APP_SECRET with it. Mailbox passwords in a backup can't be decrypted without the secret they were saved with.
7. Forgotten passwords. There's no reset email. Run (cd backend && ./target/release/splee reset-password person@example.com), which prints a new random password, signs that person out everywhere and clears their failed sign-ins. It's safe to run while the server is up. They can change the password under Account.

To start both on boot and restart them after a crash, adapt the example systemd units in deploy/systemd/. Stopping the backend's unit also stops any claude processes it started. Run a single backend per database (see below), and if you change the code, point NEXT_PUBLIC_SOURCE_URL at your source as the AGPL requires.

How it works

frontend/  Next.js 16, React 19, Tailwind 4. Proxies /api/* to the backend, so the session cookie is same-origin.
backend/   Rust: Axum 0.8, sqlx, Postgres. Runs the API and the background workers in one process.
SPEC.md    Endpoints, data contract, agent pipeline and workers.

The agent uses the local claude CLI through claude-agent-sdk-rs. Each call runs in a temp directory without your Claude settings. Research calls can only use web search and fetch, plus the X tools when BIRD_BIN is set. Writing and classification calls get no tools.

Every backend process runs the workers: the agent queue, the sender every 30 seconds, the IMAP poller every 60 seconds, the hourly campaign optimizer and the notification digests. Run one backend per database. SENDING_ENABLED=false only stops the sender, so a second backend would still poll mailboxes and process replies.

backend/vendor/claude-agent-sdk-rs is the crates.io 0.6.4 release with two patches. MessageParser::parse_known in src/internal/message_parser.rs lets every reader skip message types the crate doesn't know yet, because newer CLIs emit tool_progress and rate_limit_event. src/internal/transport/subprocess.rs spawns the CLI with kill_on_drop, so a timed-out call can't leave it running. Drop the [patch.crates-io] entry once upstream handles both.

Development

These are the checks CI runs. Run them before you open a pull request:

(cd backend && cargo clippy --all-targets -- -D warnings && cargo test && cargo test -p claude-agent-sdk-rs --lib)
(cd frontend && pnpm lint && pnpm typecheck)

CI also runs the database tests that cargo test skips. CONTRIBUTING.md shows how to run them. See it for conventions and SECURITY.md to report a vulnerability.

Responsible use

Splee sends real email to real people. You're responsible for following the law where you and your recipients are, including CAN-SPAM, GDPR, PECR and CASL. Splee gives you the tools for that: an unsubscribe link and header on every outreach email, a suppression list, bounce handling and daily limits. Send only to people with a legitimate business reason to hear from you.

License

GNU Affero General Public License v3.0. You can self-host, modify and share Splee. If you run a modified version as a service for other people, you must offer them its source code.