Update README and CHANGELOG for v0.3

What's Changed

Breaking Changes

• chat() now accepts an optional 4th parameter $options [] — existing calls with 1–3 arguments are fully backwards compatible
• chatEx() returns an array instead of string — use chat() if you need a plain string response

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New Features

• chatEx() — extended chat completion returning a full result array:
  id, content, finish_reason, tool_calls, reasoning, usage
• stream() — SSE streaming support via callback fn(string $delta, bool $done): void
• structuredChat() — JSON Schema validated responses, returns decoded PHP array directly
• getGenerationStats() — fetch token counts and cost asynchronously via /api/v1/generation
• Tool Calling — tools, tool_choice, parallel_tool_calls
• Structured Outputs — response_format with json_object and json_schema modes
• Plugins — web, file-parser, response-healing, context-compression
• Provider Routing — provider object with sort, data_collection, allow, ignore
• Reasoning Models — reasoning parameter with effort levels for Claude 3.7+, o1/o3
• Observability — session_id tracking via x-session-id header
• Output Modalities — modalities parameter (text, audio, image)

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Improvements

• chat() is now a thin wrapper around chatEx() — no duplicated logic
• Replaced deprecated max_tokens with max_completion_tokens throughout
• Error handling now parses structured API error body (error.message, error.code)
• All runtime exception messages translated to English

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Installation

composer require cheinisch/openrouter-php-client

Quick Example

// Simple – unchanged from previous versions
$client = new OpenRouterClient($apiKey);
$text   = $client->chat([['role' => 'user', 'content' => 'Hello!']], 'openai/gpt-4o-mini');

// Extended – new in v0.3
$result = $client->chatEx(
    [['role' => 'user', 'content' => 'Hello!']],
    'openai/gpt-4o-mini',
    ['plugins' => [['id' => 'web']]]
);
echo $result['content'];
echo $result['usage']['total_tokens'];

Full Changelog: v0.2.2...v0.3

v0.2.2

v0.2.2

Changes

• Change description from german to english

v0.2.1

Update CHANGELOG.md

v0.2

v0.2.0

Changes

• Change Namespace from OpenROuter\Client to cheinisch\OpenRouterClient
• Change Client::OpenRouterChat to OpenRouterClient::OpenRouterChat

v0.1.1

Full Changelog: v0.1.0...v0.1.1

v0.1.0

Full Changelog: v0.0.0.5...v0.1.0

v0.0.0.5

Update README.md

v0.0.0.4

Aktualisieren von CHANGELOG.md

v0.0.0.3

Update Client.php

v0.0.0.2: Add OpenRouterChat convenience method and README example

Introduces the OpenRouterChat static method to simplify chat API usage by requiring only API key, model, and prompt. Updates README with usage instructions and an example.