# Build with InboxSpec

Receive real email in your tests and give agents a predictable way to wait for it.

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InboxSpec gives your automated tests and agents real email addresses. Receive a message, wait for the code or link you need, and continue your application flow.

**Start with one real email**

The first-email guide takes you from an empty project to a matched message in your preferred language.

[Follow the quickstart →](https://www.inboxspec.com/docs/markdown/first-email.md)

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## Choose your path

[Receive your first email Create an inbox and wait for a verification code. Get started →](https://www.inboxspec.com/docs/markdown/first-email.md)

[Add email to your tests Build isolated fixtures and assert the right message. Write a test →](https://www.inboxspec.com/docs/markdown/ci.md)

[Capture application mail Connect your application's SMTP configuration. Set up capture →](https://www.inboxspec.com/docs/markdown/capture-smtp.md)

[Connect an agent Understand MCP setup and available connections. Explore MCP →](https://www.inboxspec.com/docs/markdown/mcp.md)

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## One workflow, your choice of client

Use [REST](https://www.inboxspec.com/docs/markdown/rest.md), the [TypeScript SDK](https://www.inboxspec.com/docs/markdown/sdk.md) or the [CLI](https://www.inboxspec.com/docs/markdown/cli.md) to register an inbox and wait for a matching message. A wait returns a match or an explicit timeout. Authentication, quota and service failures remain errors you can act on.

Already integrating? Open the [API reference](https://www.inboxspec.com/docs/markdown/api-reference.md) for request schemas and permissions.