Postbag
A form backend that routes. Point any HTML form at a Postbag endpoint and it lands in your inbox — then goes wherever it should: email, Telegram, a webhook, a partner, your CRM. Built for people who run many sites, and for the AI agents that build them.
<form action="https://api.postbag.dev/s/fm_8f3kq2" method="POST">
<input name="email" type="email" required>
<textarea name="message"></textarea>
<button>Send</button>
</form>
That's the whole integration for one form. Everything else — grouping forty forms into one stream, mapping their different fields onto one shape, sending that shape to a partner between two dates, a daily digest, never losing a submission — is there when you need it and invisible when you don't.
New here (human or AI agent)? Read
CLAUDE.mdfirst.
Why it exists
Every website has forms. Every form needs somewhere to go. Formspree and friends solve "somewhere" for one site; they fall over when you have fifteen sites feeding one partner with fifteen slightly different forms. Postbag is the source of truth for what each form collects, what each downstream system receives, and the versioned contract between them.
The one idea
The database makes it correct; events make it fast.
A submission is accepted the instant it is a row. Delivery is a durable outbox that a
worker drains with retries. Realtime nudges are an accelerator, never a transport.
If every event stream in the system died, every submission would still arrive — late,
never lost. (Inherited from the lead pipeline this generalises; see
docs/ARCHITECTURE.md.)
Status
Phase 1 — MVP live at postbag.dev (site, docs, dashboard at
/app, API at /v1). See PROGRESS.md for the live blueprint and
docs/ROADMAP.md for phases.
Documentation
Start at docs/README.md.
License
The server, dashboard, site and domain packages (apps/*, packages/core, packages/db,
packages/auth) are licensed under AGPL-3.0. The client packages that run
inside your own code — @postbag/sdk, the postbag CLI and @postbag/mcp — are
MIT. Rationale in ADR-006.