# GenerateID

Generates a unique identifier string. Useful for creating tool call IDs or request IDs.

## Signature

```go
func GenerateID() string
```

Not cryptographically secure (uses `math/rand`, matching the TypeScript AI
SDK's `Math.random()`-based implementation). Equivalent to calling
`CreateIDGenerator()()` with default options — a 16-character random string
from the alphabet `0-9A-Za-z`.

## Return Value

Returns a unique string identifier (16-character random alphanumeric string by default).

## CreateIDGenerator

Builds a custom ID generator function, mirroring the TypeScript AI SDK's
`createIdGenerator` / `generateId` from `@ai-sdk/provider-utils`.

```go
func CreateIDGenerator(opts ...CreateIDGeneratorOptions) (IDGenerator, error)

type CreateIDGeneratorOptions struct {
    Prefix    string // prepended (with Separator) to every generated ID
    Separator string // between Prefix and the random part; default "-"
    Size      int    // length of the random part; default 16
    Alphabet  string // character set for the random part; default "0-9A-Za-z"
}
```

`CreateIDGenerator` returns a `*errors.InvalidArgumentError` if `Prefix` is
set and `Separator` appears inside `Alphabet` (this would make prefix
detection ambiguous — matches the TS SDK's synchronous throw at construction
time).

```go
gen, err := ai.CreateIDGenerator(ai.CreateIDGeneratorOptions{
    Prefix: "msg",
    Size:   24,
})
if err != nil {
    log.Fatal(err)
}

id := gen() // e.g. "msg-aB3dE7fG9hJ2kL4mN6pQ8rS"
```

## Examples

### Generate Request ID

```go
package main

import (
    "fmt"

    "github.com/digitallysavvy/go-ai/pkg/ai"
)

func main() {
    requestID := ai.GenerateID()
    fmt.Printf("Request ID: %s\n", requestID)
}
```

### Custom Tool Call ID

```go
toolCall := types.ToolCall{
    ID:       ai.GenerateID(),
    ToolName: "my_tool",
    Arguments: map[string]interface{}{
        "param": "value",
    },
}
```

### Session Tracking

```go
type Session struct {
    ID        string
    CreatedAt time.Time
}

session := Session{
    ID:        ai.GenerateID(),
    CreatedAt: time.Now(),
}

fmt.Printf("Session: %s\n", session.ID)
```

## See Also

- [Tool](https://goaisdk.com/docs/reference/ai/tool.md) - Tool definition
- [GenerateText](https://goaisdk.com/docs/reference/ai/generate-text.md) - Text generation