---
title: Identity (TypeID)
description: How Relay uses prefix-qualified, globally unique identifiers for every entity.
---

Every entity in Relay has a TypeID. TypeIDs are globally unique, sortable, URL-safe identifiers built on UUIDv7 with a human-readable prefix that tells you what kind of entity you're looking at.

A TypeID looks like this:

```
evt_01h455vb4pex5vsknk084sn02q
```

The `evt` prefix identifies this as an event. The suffix is a base32-encoded UUIDv7 that encodes creation time, so IDs sort chronologically.

## The `id` package

The `id` package wraps the [TypeID Go library](https://github.com/jetify-com/typeid-go) (v2) with a single `ID` struct. All entity types share the same struct -- the prefix distinguishes them.

### Creating IDs

```go
import "github.com/xraph/relay/id"

eventTypeID := id.New(id.PrefixEventType)  // evtype_01h455vb...
endpointID  := id.New(id.PrefixEndpoint)   // ep_01h455vb...
eventID     := id.New(id.PrefixEvent)      // evt_01h455vb...
```

Convenience constructors: `id.NewEventTypeID()`, `id.NewEndpointID()`, `id.NewEventID()`, `id.NewDeliveryID()`, `id.NewDLQID()`, `id.NewSecretID()`.

### Parsing IDs

```go
parsed, err := id.Parse("evt_01h455vb4pex5vsknk084sn02q")
parsed, err := id.ParseWithPrefix("evt_01h455vb...", id.PrefixEvent)  // validates prefix
parsed, err := id.ParseEventID("evt_01h455vb...")                     // convenience
```

### Nil ID

```go
var empty id.ID
empty.IsNil()  // true
empty.String() // ""
id.Nil.IsNil() // true
```

### Database storage

`id.ID` implements `Scanner` and `driver.Valuer`. Stores as a string, returns `NULL` for nil IDs.

### JSON serialization

`id.ID` implements `TextMarshaler` and `TextUnmarshaler`. Nil IDs serialize as empty strings.

## Prefix reference

| Constant | Prefix | Entity |
|----------|--------|--------|
| `id.PrefixEventType` | `evtype` | Event type |
| `id.PrefixEndpoint` | `ep` | Webhook endpoint |
| `id.PrefixEvent` | `evt` | Event |
| `id.PrefixDelivery` | `del` | Delivery attempt |
| `id.PrefixDLQ` | `dlq` | Dead letter queue entry |
| `id.PrefixSecret` | `whsec` | Signing secret |