> ## Documentation Index
> Fetch the complete documentation index at: https://docs.actioncodes.org/llms.txt
> Use this file to discover all available pages before exploring further.

# CodeGenerator

The `CodeGenerator` class provides static utilities for generating, validating, and normalizing action codes and prefixes in the Action Codes Protocol. It ensures codes are deterministic, secure, and conform to protocol standards.

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## Constants

* `TIME_WINDOW_MS`: Code validity window in milliseconds (default: protocol TTL)
* `CODE_DIGITS`: Number of digits in the code (default: 8)
* `MIN_PREFIX_LENGTH`: Minimum allowed prefix length
* `MAX_PREFIX_LENGTH`: Maximum allowed prefix length

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## Static Methods

### validatePrefix

```ts theme={null}
static validatePrefix(prefix: string): boolean
```

Validates the format of a prefix. Returns `true` if valid, `false` otherwise.

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### validateCodeFormat

```ts theme={null}
static validateCodeFormat(code: string): boolean
```

Validates that a code is in the correct format (prefix + exactly 8 digits). Returns `true` if valid.

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### validateCodeDigits

```ts theme={null}
static validateCodeDigits(code: string): boolean
```

Checks that the numeric part of a code is exactly 8 digits. Returns `true` if valid.

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### normalizePrefix

```ts theme={null}
static normalizePrefix(prefix: string): string
```

Normalizes a prefix (converts protocol default to empty string, validates others). Throws if invalid.

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### generateCode

```ts theme={null}
static generateCode(pubkey: string, prefix?: string, timestamp?: number): { code: string; issuedAt: number; expiresAt: number }
```

Generates a deterministic 8-digit code based on public key, prefix, and timestamp. Returns the code, issuedAt, and expiresAt.

***

### deriveCodeHash

```ts theme={null}
static deriveCodeHash(pubkey: string, prefix?: string, timestamp?: number): string
```

Derives a full SHA-256 hash for storage or encryption key generation.

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### getExpectedCode

```ts theme={null}
static getExpectedCode(pubkey: string, timestamp: number, prefix?: string): string
```

Returns the expected code for a given public key and timestamp.

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### validateCode

```ts theme={null}
static validateCode(code: string, pubkey: string, timestamp: number, prefix?: string): boolean
```

Validates if a code matches the expected code for a given public key and timestamp.

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### isValidTimestamp

```ts theme={null}
static isValidTimestamp(timestamp: number): boolean
```

Checks if a timestamp falls within the valid time window.

***

## Example

```ts theme={null}
import { CodeGenerator } from "@actioncodes/protocol";

const pubkey = "...";
const prefix = "OTA";
const timestamp = Date.now();

const { code, issuedAt, expiresAt } = CodeGenerator.generateCode(pubkey, prefix, timestamp);
console.log(code); // e.g., "OTA12345678"

const isValid = CodeGenerator.validateCode(code, pubkey, timestamp, prefix);
console.log(isValid); // true
```

***