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

Every entity in Nexus 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:

```
tenant_01h455vb4pex5vsknk084sn02q
```

The `tenant` prefix identifies this as a tenant. 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/nexus/id"

tenantID  := id.New(id.PrefixTenant)   // tenant_01h455vb...
keyID     := id.New(id.PrefixKey)      // key_01h455vb...
usageID   := id.New(id.PrefixUsage)    // usage_01h455vb...
requestID := id.New(id.PrefixRequest)  // req_01h455vb...
```

Convenience constructors: `id.NewTenantID()`, `id.NewKeyID()`, `id.NewUsageID()`, `id.NewRequestID()`.

### Parsing IDs

```go
parsed, err := id.Parse("tenant_01h455vb4pex5vsknk084sn02q")
parsed, err := id.ParseWithPrefix("tenant_01h455vb...", id.PrefixTenant)  // validates prefix
parsed, err := id.ParseTenantID("tenant_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.PrefixTenant` | `tenant` | Tenant |
| `id.PrefixKey` | `key` | API key |
| `id.PrefixUsage` | `usage` | Usage record |
| `id.PrefixRequest` | `req` | Request |