Matthew Meszaros
b9cce2fbdc
* feat: ease a graduating mailbox into cold volume instead of handing it the full cap the day it joins a campaign: cold sending read warmup HEALTH but never whether the mailbox had actually warmed enough, so one at its 40/day warmup ceiling could send 50 cold the next morning, which is the post-warmup spike providers penalise; effectiveCap gains a min() term that starts the mailbox at 5, 10 or 20 a day by how long it warmed and adds 5 per clean day toward its own cap, freezing on a spam placement through the same union-of-freezes the warmup ramp uses, anchored by a new cold_ramp_started_at stamped idempotently on the first cold send and reset on org import because it raises a ceiling the destination never watched being earned; mailboxes that never warmed are not gated, since capping senders who never opted into warmup is a different decision from smoothing the transition out of it * feat: anchor the graduation ramp on a CONFIRMED send, and make the hold the drawer reports the hold the scheduler applies: stamping cold_ramp_started_at at dispatch started the clock on a send the worker then failed, so a mailbox climbed on days it had not proven anything, and the stamp moves to the worker's EMAIL_SENT; separately the drawer computed its hold over every placement while ColdCeiling only counts placements after the first cold send, so a placement predating the ramp read as paused while the scheduler kept climbing, and both now go through one ColdHeldUntil * fix: restore the Callout closing tag my conflict resolution dropped, which types:check and lint both pass and only pnpm build catches
The open-source agentic cold email and warmup platform.
Features · How it works · Quick start · Self-hosting · Docs · Community · Support
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Warmbly
Warmbly runs cold email campaigns from the mailboxes you already own and warms them so they keep landing in the inbox. Opens, clicks, and replies land in a shared dashboard the moment they happen, and it's AI-native, so your team and its agents work in it together, live.
https://github.com/user-attachments/assets/378a510a-bb99-425f-925e-04300184938b
Features
- Campaigns - multi-step sequences with per-mailbox caps and spacing
- Unified inbox - every mailbox and reply in one place
- CRM - contacts, pipelines, deals, tasks, meetings
- Warmup - a pool of monitored mailboxes, not throwaway accounts
- Deliverability - bounces, complaints, suppression, inbox placement
- Automations - visual reply playbooks with AI steps
- Integrations - HubSpot, Slack, Zapier, REST API, webhooks
- Realtime - live presence and edits across your team
How it works
Warmbly splits into a control plane (backend API, consumer, Postgres, Redis, and the event bus) that owns all state, and an execution plane of interchangeable Go workers that send and sync mail. Workers never touch Postgres, and outbound mail leaves through each mailbox's own provider, not the worker's IP, so you add throughput by running more workers.
flowchart LR
MB["Your mailboxes"] --> API
subgraph CP["Control plane"]
direction TB
API["Backend API"] --> DB[("Postgres")]
API --> BUS{{"Event bus"}}
end
BUS --> W1["Worker"]
BUS --> W2["Worker"]
BUS --> W3["Worker"]
W1 --> P["Gmail · Microsoft · SMTP"]
W2 --> P
W3 --> P
P --> R["Recipients"]
Secrets use envelope encryption, with a local AES master key by default or AWS KMS if you prefer. Full write-up in the architecture docs.
Quick start
You need Docker, Go 1.25, and pnpm.
git clone https://github.com/warmbly/warmbly && cd warmbly
make dev
Open http://localhost:5173 and log in with dev@warmbly.com / password123;
the login code lands in Mailpit at http://localhost:18025. Every make target,
the native services, and how seeding works are in the
local development guide.
Warning
make devandmake upshare one database, and seeded fixture accounts claim the instance. Planning to self-host from the same machine? Read first run first.
Self-hosting
Warmbly runs with no cloud account of any kind: no AWS, no GCP, no Stripe, no Kafka. One command brings up the whole platform on local, open-source pieces:
git clone https://github.com/warmbly/warmbly && cd warmbly
make up
That is the whole install: make up waits for the backend and prints a one-time
link that claims the instance and makes you its admin. You need Docker with
Compose v2 and about 10 GB of free disk. If anything looks wrong, make doctor
prints the instance state and every failing check.
From here the
self-hosting guide
covers the rest: your own secrets, production hardening, mail and single
sign-on, HTTPS, connecting Gmail and Microsoft mailboxes, scaling workers, and
backups. Account recovery and every operator command live in
warmblyctl, the CLI baked
into the backend image; it talks to the database directly, so it works when
signing in does not.
Documentation
The full docs live at docs.warmbly.com.
| Read this | To learn |
|---|---|
| Self-hosting guide | Step-by-step install, then production, backups, and scaling the worker fleet |
| First run | Claiming the instance, reissuing the setup link, and what to do when accounts already exist |
| Accounts and access | Registration modes, inviting people with or without a mail relay, SSO, and recovering access |
warmblyctl |
The operator CLI: creating accounts, setting passwords, granting admin, and instance status |
| Configuration reference | Every environment variable, its default, and whether changing it needs a restart |
| Instance health | The checks the admin panel runs against your deployment, and make doctor |
| Troubleshooting | The errors self-hosters actually hit, and the command that fixes each one |
| Local development | Every make target, the native services, and how seeding works |
| Architecture | How the control plane and workers split the job, plus the encryption model |
| API reference | Endpoints, auth, permissions, and webhooks |
Community
Have a question, found a bug, or want to shape where Warmbly goes next?
- Discord - chat with the team and other senders
- GitHub Issues - report bugs and request features
- X / @WarmblyHQ - follow along for updates and releases
- Email - reach us at
team@warmbly.com
Support and enterprise
Note
Need a hand? We are happy to help. Ask in Discord, open a GitHub issue, or email
team@warmbly.com, and someone on the team will get back to you.Running Warmbly at scale, or would you rather we run it for you? We offer enterprise support and managed infrastructure: we can host and operate the whole platform for your organization, help you deploy and scale the worker fleet, tune deliverability, migrate your sending onto Warmbly, and stand behind it with a support agreement built around your team. Tell us what you need at
team@warmbly.comor reach out on X.
Star the repository ⭐
Contributing
Pull requests are welcome. Keep each one to a single logical change, and open an
issue first for larger design or product changes. Before you open a PR, run the
checks for the tree you touched (make fmt and make lint for Go, pnpm typecheck and pnpm lint for the frontends). See CONTRIBUTING.md.
Security
Found a vulnerability? Email team@warmbly.com instead of opening a public issue.
We prefer responsible disclosure and credit reporters in the release notes.
License
Apache License 2.0. Copyright 2026 Mindroot Ltd. See LICENSE.