Stamp0

Why We Built Stamp0: Programmatic Inboxes for the AI Era

by Stamp0 Team

Email is everywhere in software. User signups, password resets, order confirmations, team invitations, two-factor authentication-the list goes on. Yet testing these flows has always been painful. We built Stamp0 to fix that.

The Old Way: A Developer's Nightmare

If you've ever written automated tests for email flows, you know the pain:

Shared Test Inboxes

The classic approach: everyone on the team shares test@yourcompany.com. Your Playwright test sends a verification email. So does your colleague's test. So does CI. Now you're parsing through dozens of emails trying to find yours, hoping the timing works out, praying no one else grabbed it first.

// The old way - hope and pray
await page.fill('#email', 'shared-test@company.com');
await page.click('button[type="submit"]');
// Wait... which email is mine?
// Is it even here yet?
// Did someone else's test grab it?

Gmail Plus Addressing

Some teams get clever with test+randomstring@gmail.com. Better, but you're still hitting Gmail's API, dealing with OAuth, rate limits, and the constant fear that Google will change something and break your entire test suite.

Self-Hosted Mail Servers

The "proper" solution: run your own mail server. Now you're maintaining Postfix, dealing with DNS records, SPF, DKIM, and suddenly your test infrastructure is more complex than your actual product.

Enter the AI Agent Era

Here's what changed: AI agents.

We're no longer just writing tests that run in CI. We're building AI agents that interact with the real world-agents that need to sign up for services, verify emails, complete authentication flows, and operate autonomously.

An AI agent using Claude or GPT-4 needs to:

  • Create accounts on websites
  • Receive and parse verification emails
  • Extract OTP codes automatically
  • Complete multi-step authentication flows

Traditional email testing tools weren't built for this. They assume a human is orchestrating the test, manually checking inboxes, copy-pasting codes.

Stamp0: Built for Programmatic Access

Stamp0 is different. Every feature is designed for machines first:

Instant, Disposable Inboxes

Create an inbox in milliseconds. Use it for one test. Throw it away. No cleanup, no conflicts, no shared state.

// Create a unique inbox for this test
const inbox = await stamp0.createInbox();
// inbox.email = "abc123@stamp0.email"

await page.fill('#email', inbox.email);
await page.click('button[type="submit"]');

// Wait for the email with a simple API call
const email = await stamp0.waitForEmail(inbox.id, {
  timeout: 30000,
  subject: /verify/i
});

// Extract what you need
const code = email.body.match(/\d{6}/)[0];

MCP Server for AI Agents

This is where Stamp0 shines. Our MCP (Model Context Protocol) server lets AI agents interact with email natively. Claude, GPT-4, or any MCP-compatible agent can:

  • Request a new inbox
  • Check for incoming emails
  • Parse email content
  • Extract verification codes
  • All through natural tool calls
Agent: "I need to sign up for this service. Let me create a test inbox."
[Uses stamp0_create_inbox tool]

Agent: "Now I'll fill in the signup form with this email..."
[Completes signup flow]

Agent: "Let me check for the verification email."
[Uses stamp0_get_emails tool]

Agent: "Found it. The verification code is 847293."

No human in the loop. No manual email checking. The agent handles everything autonomously.

First-Class API Support

Every operation is an API call. REST endpoints for when you need direct control. Webhooks for real-time notifications. SDKs for popular languages. Everything you need for CI/CD pipelines, test frameworks, and automation scripts.

Traditional Tools vs Stamp0

| Feature | Traditional Approach | Stamp0 | |---------|---------------------|--------| | Inbox creation | Manual setup | Instant API call | | Isolation | Shared inboxes | Unique per test | | AI agent support | None | Native MCP server | | API access | Limited/complex | First-class REST API | | Cleanup | Manual | Automatic | | Setup time | Hours/days | Minutes |

Real-World Use Cases

Automated E2E Testing

Your Playwright, Cypress, or Selenium tests create unique inboxes for each run. No flaky tests from email collisions. No manual cleanup.

AI Agent Development

Building an agent that needs to interact with email-gated services? Stamp0's MCP server makes email just another tool in your agent's toolkit.

QA Environments

Spin up hundreds of test inboxes for load testing. Each inbox is isolated. Each test is independent. Scale without limits.

Development Workflows

Developers testing locally get their own inboxes. No more "who has the test account password?" conversations.

The Future is Agentic

We're entering an era where AI agents don't just answer questions-they take actions. They browse the web, fill out forms, complete transactions. Email is a critical part of that world.

Stamp0 is built for this future. Not as an afterthought, but as a core design principle. Programmatic access. Machine-readable responses. AI-native tooling.

Get Started

Stamp0 is free to start. Create unlimited inboxes, receive unlimited emails. No credit card required.

Whether you're writing your first Playwright test or building the next generation of AI agents, Stamp0 gives you the email infrastructure you need.

Get started free or read the docs to learn more.