Show HN: GoodSender – the email API for makers and AI agents

Free Email API — GoodSender · Transactional & Marketing

// STEP_01 — MARKETING EMAIL

Permission. Then send.

Marketing email starts with permission. Every recipient confirms before you can reach them — enforced at the API. Once they're in, send away. Mailbox providers reward this. So do we.

01

Add Recipient

Send a consent request to any email address. It takes ~150ms.

02

Confirmation

They click a link in a standard, high-reputation system email.

03

Confirmed

The recipient is unlocked for your API key globally.

04

Send Email

ONE HTTP CALL

Hit /v1/emails/send with markdown, HTML, or plain text. We render, suppress, and deliver from the high-reputation pool.

// STEP_02 — TRANSACTIONAL

Transactional templates just work.

Pick a template, pass your variables, and it's in the inbox. Transactional emails are pre-cleared — no consent workflow required.

encrypted

MFA Enrollment

Verify a user as they turn on multi-factor authentication.

devices

New Device

Alert users when their account is accessed from a new device.

login

Login

Magic-link or one-click sign-in without a password.

receipt_long

Order Completed

Confirm a successful checkout with receipt-ready details.

pin

OTP Code

One-time passcodes for 2FA and passwordless login.

more_horiz

More coming

We expand the catalog over time based on what customers ask for.

// All other emails → permission required. Transactional → ship it.

// STEP_03 — ENGAGEMENT

The Engagement Check

Permission opens the door. Engagement keeps it open. We watch every signal — opens, clicks, complaints, silences — and handle list hygiene so your sender reputation only goes up.

01

Watch Every Signal

Opens, clicks, bounces, and complaints — tracked per recipient, aggregated into a live engagement score by our agents.

02

Re-Permission On Drift

Six months without engagement triggers an automatic re-permission ping. No response? They drop off your list — not your problem.

03

Auto-Suppress

WORKSPACE-WIDE

Unsubscribes and spam complaints are suppressed instantly across your workspace. You physically cannot send to them again. Reputation: protected.

Permission, engagement, and one HTTP call.

All of it lives behind a single endpoint. Pass markdown, HTML, or plain text — we handle rendering, suppression, and delivery on the shared high-reputation pool.

curl -X POST https://api.goodsender.com/v1/emails/send \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "emails": [ { "from": { "email": "[email protected]", "name": "Example Sender" }, "to": [{ "email": "[email protected]" }], "subject": "Hello from GoodSender", "markdown_content": "## Hello from GoodSender\nYour first email is on the way." } ] }'

markdown

Markdown in, email out

No template language. No rendering pipeline. Pass the model output directly — we handle the conversion to bulletproof email HTML.

Welcome aboard

Thanks for signing up. Here's what to expect...

• Feature one
• Feature two

YOUR_MARKDOWN

double_arrow

Welcome...

Thanks for...

Feature one

GOOD_SENDER_CORE

double_arrow

Gmail

Outlook

Apple Mail

90+ MORE

INBOX_READY

// MCP — COMING SOON(Model Context Protocol)

Run a mailing list from the chat window.

Draft the next issue in your assistant, pick the audience, send. New subscribers get a consent request in the background — their first issue goes out the instant they confirm.

Available in:auto_awesomeClaudechatChatGPTterminalTerminalsmart_toyOpenClaw

Craft

Draft the next issue and preview it right inside Claude, ChatGPT, or your terminal. Refine until it looks right — no copy-pasting between tabs.

Pick

Send to the whole list, a segment, or a fresh batch of emails. Your agent lines up the audience in plain language.

Send

Ship now or schedule it via your assistant's task system. New subscribers get a consent request in the background — their issue goes out the moment they confirm.

// PROVENANCE

Earned, not built.

2009 — our founders built SendGrid to help developers solve the problem of emails landing in spam. The cloud infrastructure shipped. The deliverability problem didn't go away. Deliverability is earned, not built.

2018 — we left the space. Years later, the core problem was still there. Senders were still fighting for the inbox.

2025 — we built Laneful: email engineers, custom IP lanes, and AI agents that monitor traffic health for the largest senders in the world. Tailored involvement that reduces ESP costs and earns top-tier deliverability at scale.

Today — GoodSender is that same playbook, automated. Permission, engagement, and reputation wired into a single API for smaller teams and AI agents.

// AND_IT'S_RADICALLY_AFFORDABLE

Earned reputation scales cheap.

When every recipient consented and every list is healthy, infrastructure costs collapse. We pass the savings on. 100K free / month, $1 per 100K beyond. Here's how that compares:

FREE TIER

$0

First 100k emails/month free — covers everything you send, transactional and marketing alike. Practically free for most businesses at any realistic volume.

PAY AS YOU GO

$1/100k

Beyond your free 100k — $1 per additional 100k. No subscriptions, no surprises.

TRANSACTIONAL

No gate

Transactional templates — MFA, New Device, Login, Order Completed, OTP — don't require permission. Catalog grows with customer demand.

swipe swipe to compare

PROVIDER100K/MO500K/MO1M/MO10M/MO

Resend$35$350$650CUSTOM

SendGrid (Twilio)$34.95$499$499 (700K)CUSTOM

Mailtrap$30$300$750CUSTOM

Mailgun$75$400$700CUSTOM

Amazon SES$10-12$50-60$100-120CUSTOM

GoodSender$0$4$9$99

// 100K and 1M prices verified on competitor pricing pages on 2026-04-20. SendGrid has no published 1M tier — the figure shown is the closest published one (700K = $499). 500K and 10M remain approximate. Competitor pricing may vary by plan, volume tier, and billing period.

Who it's for

// BUILT_FOR

Makers & Builders

_ Indie developers & solo founders

_ AI startups & agentic workflow builders

_ Small teams & side projects

_ Anyone tired of $30–50/mo email bills

// NOT_FOR

Marketing Teams

✕ Enterprise marketing departments

✕ Marketing automation heavy users

Need enterprise-grade volume?

Check out Laneful →

// HARD_NO: Cold outreach is spam. We don't enable it at any volume.

Stop fighting deliverability. Start earning it.

Add your domain, grab an API key, and send your first email — with permission and engagement built in — in under 10 minutes.

Read the FAQ →