Question 1

How do I send my first email with Inbox OSS?

Accepted Answer

Sign up, verify your sending domain by publishing the DKIM and SPF records shown in the Domains tab, create an API key from Settings, then POST your message to /api/v1/mail/send with the SendGrid-compatible JSON body. The Quickstart guide walks through this end-to-end in under 5 minutes.

Question 2

Is the API compatible with SendGrid?

Accepted Answer

Yes. POST /api/v1/mail/send accepts the SendGrid v3 Mail Send body verbatim — personalizations, dynamic template substitutions, attachments, categories, custom_args, tracking_settings, mail_settings. You can point any official SendGrid SDK at Inbox OSS by changing the hostname and API key.

Question 3

How do I authenticate API requests?

Accepted Answer

Pass your API key in the Authorization header as a Bearer token: Authorization: Bearer <key>. Keys are SHA-256 hashed at rest. Scopes (Mail Send, Suppressions, Stats, Admin) limit each key to specific endpoints; create granular keys per environment from Settings → API Keys.

Question 4

What webhook events does Inbox OSS deliver?

Accepted Answer

processed, deferred, delivered, bounced, blocked, opened, clicked, unsubscribed, spamreport, group_unsubscribe, group_resubscribe. Signed with HMAC-SHA256 in the X-Webhook-Signature header. Failed deliveries retry with exponential backoff up to 5 days.

Question 5

What SDKs are available?

Accepted Answer

Official SDKs for Node.js, Python, Go, Ruby, PHP, Java, .NET, and Rust. All maintained by the platform team. SendGrid SDK users can drop in Inbox OSS by changing the hostname — both expose the same v3 mail send surface.

Build with Inbox OSS

Documentation sections

Need help getting started?