zerodrop-go

Email verification infrastructure for CI pipelines and AI agents.

Send a verification email. Catch it at the edge. Get email.OTP and email.MagicLink back — auto-extracted, no regex, no Docker, no signup.

email, err := client.WaitForLatest(ctx, inbox, nil)

email.OTP       // "123456" — auto-extracted
email.MagicLink // "https://..." — no regex needed

Documentation · GitHub · Status

Install

go get github.com/zerodrop-dev/zerodrop-go

Zero dependencies — stdlib only. Go 1.21+.

Zero-Auth Mode (Local Development)

package main

import (
	"context"
	"fmt"

	zerodrop "github.com/zerodrop-dev/zerodrop-go"
)

func main() {
	client := zerodrop.New()
	inbox := client.GenerateInbox()
	// → "swift-x7k29a@zerodrop-sandbox.online"

	email, err := client.WaitForLatest(context.Background(), inbox, nil)
	if err != nil {
		panic(err)
	}

	fmt.Println(email.Subject)   // "Reset your password"
	fmt.Println(email.OTP)       // "123456" — auto-extracted, no regex
	fmt.Println(email.MagicLink) // "https://..." — auto-extracted
}

CI Pipeline Mode (go test)

func TestSignupEmailVerification(t *testing.T) {
	client := zerodrop.New()
	inbox := client.GenerateInbox()

	// Trigger your app's signup flow with the inbox address...
	signUp(t, inbox)

	ctx := context.Background()
	email, err := client.WaitForLatest(ctx, inbox, &zerodrop.Options{
		Timeout: 15 * time.Second,
	})
	if err != nil {
		t.Fatalf("no verification email: %v", err)
	}

	if email.OTP == "" {
		t.Fatal("expected OTP in verification email")
	}

	// Continue the flow with email.OTP...
	verify(t, inbox, email.OTP)
}

SSE — Sub-Second Delivery

WaitForLatest uses Server-Sent Events by default. Emails arrive in under a second instead of waiting for the next poll. Polling fallback is automatic.

// Force polling mode if needed
email, err := client.WaitForLatest(ctx, inbox, &zerodrop.Options{
	DisableSSE: true,
})

Email Filtering

Filter by sender, subject, body, or extracted fields when multiple emails land in the same inbox:

email, err := client.WaitForLatest(ctx, inbox, &zerodrop.Options{
	Timeout: 15 * time.Second,
	Filter: &zerodrop.Filter{
		From:    "noreply@yourapp.com",
		Subject: "Verify",
		HasOTP:  zerodrop.Bool(true),
	},
})

All string filters are case-insensitive partial matches.

OTP Auto-Extraction

ZeroDrop extracts OTP codes and magic links at Cloudflare's edge before emails reach your test. No regex required.

email.OTP       // "123456" — 4-8 digit verification code
email.MagicLink // "https://app.com/verify?token=abc" — verification/reset link
email.Body      // Full plain-text body if you need it

Both fields are empty strings if not detected.

Parallel Test Runs

GenerateInbox runs locally — no network request, no throttling:

// Safe to run in parallel — each test gets an isolated inbox
func TestParallelSignups(t *testing.T) {
	t.Parallel()
	client := zerodrop.New()

	for i := 0; i < 50; i++ {
		i := i
		t.Run(fmt.Sprintf("user-%d", i), func(t *testing.T) {
			t.Parallel()
			inbox := client.GenerateInbox() // unique, zero collision
			// ...
		})
	}
}

Workspaces

client := zerodrop.New(
	zerodrop.WithAPIKey(os.Getenv("ZERODROP_API_KEY")),
)

Self-Hosted

client := zerodrop.New(
	zerodrop.WithBaseURL("https://your-instance.yourdomain.com"),
)

API

Function	Description
New(opts ...ClientOption) *Client	Create a client. No options = free sandbox mode.
(*Client).GenerateInbox() string	Instant inbox address. No network request.
(*Client).FetchLatest(ctx, inbox, filter) (*Email, error)	Latest matching email or nil.
(*Client).WaitForLatest(ctx, inbox, opts) (*Email, error)	Block until email arrives. SSE + polling fallback.
Bool(v bool) *bool	Helper for Filter.HasOTP / Filter.HasMagicLink.

Errors

email, err := client.WaitForLatest(ctx, inbox, nil)

var timeoutErr *zerodrop.TimeoutError
if errors.As(err, &timeoutErr) {
	// No email arrived — check your app is sending correctly
}

if errors.Is(err, zerodrop.ErrUnauthorized) {
	// Invalid API key
}

Free vs Workspace

	Free	Workspace
Inbox generation	✓	✓
OTP auto-extraction	✓	✓
Magic link extraction	✓	✓
Email filtering	✓	✓
SSE delivery	✓	✓
Email retention	30 min	Extended
Custom domains	✗	✓
API key	✗	✓

Get a Workspace at zerodrop.dev

License

MIT