Hackathon-ready · Open source · MIT v1.0.0

Email that works while you build.

A local proxy that sits between your app and any email provider. Swap providers, mock sends, and debug — without touching a single line of your app code.

🪟 Download for Windows.exe · 15.9 MB 🍎 Download for macOSUniversal · 15.9 MB 🐧 Download for Linuxx86_64 · 31.8 MB

or run from source with Python →

macOS: if Gatekeeper blocks the app, right-click → Open on first launch. · Windows: SmartScreen may warn — click "More info" → "Run anyway".

~ /protopost

# clone & start in 3 commands

$ git clone https://github.com/pgokul695/ProtoPost.git && cd ProtoPost

$ pip install -r requirements.txt

$ uvicorn backend.main:app --reload --port 8000

INFO: Application startup complete.

INFO: Uvicorn running on http://localhost:8000

# send your first email

$ curl -X POST http://localhost:8000/api/send \

-H "Content-Type: application/json" \

-d '{"from":"[email protected]","to":["[email protected]"],"subject":"Hello"}'

✓ {"status":"success","provider":"resend","processing_time_ms":341}

Your App

→

POST /api/send

→

ProtoPost

→

Resend / Gmail or Sandbox 📦

Core features

Everything you need.

Nothing you don't.

📦

Sandbox Mode

Captures every email locally. Nothing is ever sent. Flip one toggle — your app gets a 200 OK, no provider calls are made.

🔀

Automatic Failover

If your primary provider returns a 429 or 500, ProtoPost catches it and retries with the next configured provider automatically.

⚖️

Manual Load Balancing

Assign percentage weights to providers — 70% Resend, 30% Gmail. Traffic splits probabilistically. Change weights live with no restart.

🧭

Guided Setup Wizards

Built-in step-by-step walkthroughs for Gmail App Passwords and Resend — right inside the dashboard. No docs tab needed.

📋

Full Outbox & Logs

Every email logged: timestamp, recipient, provider used, status, and response time. Click any row to inspect the raw JSON payload.

⚡

Zero App Changes

One endpoint. Your app never knows which provider is running. Swap from Resend to Gmail in 2 clicks without deploying anything.

Providers

Connect any sender.

API keys, App Passwords, raw SMTP — ProtoPost handles all of them from the same dashboard form.

Resend

Free tier

Developer-first email API. 3,000 emails/month free. Best for production-quality delivery with verified domains.

3,000 / mo free ~5 min setup Needs domain

Mailtrap

Free tier

Transactional email API with a built-in test inbox. 1,000 emails/month free. Great for staging environments.

1,000 / mo free ~3 min setup No domain needed

Gmail App Password

Google Account

Use your existing Google account. ~500 emails/day. Guided setup walkthrough built into the dashboard.

~500 / day ~5 min setup Needs 2FA

Custom SMTP

Any server

SendGrid, Mailgun, AWS SES, Zoho, Office 365 — any SMTP server. Configure host, port, TLS/SSL, and credentials.

Port 587 / 465 / 2525 TLS + SSL flags ~2 min setup

Getting started

Pick your path.

Three ways to get ProtoPost running — not sequential, pick one.

Option A RECOMMENDED

Just run it

No Python. No terminal. Double-click and go.

↓ Windows · ↓ macOS · ↓ Linux

A short wizard sets your port and optional auth token on first launch. Browser opens automatically.

macOS: right-click → Open on first run. · Windows: More info → Run anyway if SmartScreen appears.

Option B

Run from source

For developers. Requires Python 3.11+.

git clone https://github.com/pgokul695/ProtoPost.git
cd ProtoPost
pip install -r requirements.txt

Option C

Host on Render

Deploy to the cloud. Free tier, always-on.

📖 Full deploy guide ↗

Get started — executable path

Download the executable

Pick your platform and download the ProtoPost executable. No installer needed.

↓ Windows · ↓ macOS · ↓ Linux

macOS: right-click → Open on first run. · Windows: More info → Run anyway if SmartScreen appears.

A short wizard sets your port

On first launch a wizard sets your port and optional auth token. No config file to edit. Browser opens automatically.

Add a provider from the dashboard

Open the Providers tab, click "Add Provider", pick your type. The built-in wizard walks you through getting credentials for Gmail and Resend.

Point your app at one endpoint

Change your email calls to hit ProtoPost. That's the only code change you'll ever make.

POST http://localhost:PORT/api/send

{
  "from": "you@yourdomain.com",
  "to": ["recipient@example.com"],
  "subject": "Hello from ProtoPost",
  "body_html": "<h1>It works!</h1>"
}

Clone and install

git clone https://github.com/pgokul695/ProtoPost.git
cd ProtoPost
pip install -r requirements.txt

Start the server

Browser opens at localhost:8000. No config file to edit first.

uvicorn backend.main:app --reload --port 8000
# Windows: python -m uvicorn backend.main:app --reload --port 8000

Add a provider from the dashboard

Open the Providers tab, click "Add Provider", pick your type. The built-in wizard walks you through getting credentials for Gmail and Resend.

Point your app at one endpoint

Change your email calls to hit ProtoPost. That's the only code change you'll ever make.

POST http://localhost:PORT/api/send

{
  "from": "you@yourdomain.com",
  "to": ["recipient@example.com"],
  "subject": "Hello from ProtoPost",
  "body_html": "<h1>It works!</h1>"
}

📄 Docker guide ↗

Fork the repo

Fork the ProtoPost repository to your GitHub account. Fork on GitHub ↗

Create a Web Service on Render

Go to render.com → New → Web Service → connect your forked repo. Then set:

Build Command: pip install -r requirements.txt
Start Command: uvicorn backend.main:app --host 0.0.0.0 --port $PORT

Set environment variables

In Render → your service → Environment tab, add:

HOST = 0.0.0.0
AUTH_TOKEN = your-secret-token ← optional but strongly recommended
DATABASE_PATH = /var/data/emails.db ← requires a Render Disk (see note)
CONFIG_PATH = /var/data/config.json

Without a Render Disk, emails.db resets on every deploy. Add a Disk in Render → your service → Disks, mount path: /var/data.

Deploy

Click “Create Web Service”. Render builds and deploys automatically. Your instance is live at:

https://your-service-name.onrender.com

Point your app at the hosted endpoint

POST https://your-service-name.onrender.com/api/send

# If you set AUTH_TOKEN, add the header:
Authorization: Bearer your-secret-token

📖 Full deploy guide ↗

Email that works while you build.

Everything you need.

Connect any sender.

Pick your path.

You control the traffic.

Test without the mess.

Docs

Before you go live.