Feat: Evented telemetry

[vinitkadam03]

Description

Adds comprehensive telemetry support to Prism, enabling observability through configurable drivers. This feature was built on the foundations of the eventelemetry branch by @sixlive.

Features

• Configurable Drivers: Choose from null, log, or otlp drivers via PRISM_TELEMETRY_DRIVER
• Phoenix/Arize Integration: First-class support for Arize Phoenix with OpenInference semantic conventions
• Custom Drivers: Register custom telemetry drivers via factory classes or closures
• User Context Tracking: Track user_id, session_id, and agent across spans
• Streaming Support: Telemetry for streaming responses with StreamStartEvent/StreamEndEvent capture
• Async Export: Queue-based span export with configurable retry (3 attempts, 5s backoff)
• Exception Recording: Automatic SpanException dispatch on failures with context preservation

Configuration

// Enable telemetry
PRISM_TELEMETRY_ENABLED=true
PRISM_TELEMETRY_DRIVER=phoenix

// Phoenix configuration
PHOENIX_ENDPOINT=https://app.phoenix.arize.com/v1/traces
PHOENIX_API_KEY=your-api-key

Usage

Prism::text()
    ->using('openai', 'gpt-4')
    ->forUser(auth()->id())
    ->forConversation($conversation->id)
    ->forAgent('support-bot')
    ->withPrompt('Hello')
    ->asText();

Global Context

// In a service provider
Prism::defaultTelemetryContext(fn () => [
    'user_id' => auth()->id(),
    'environment' => app()->environment(),
]);

Optional Dependencies

For OTLP drivers (Phoenix, etc.), install:

composer require open-telemetry/sdk open-telemetry/exporter-otlp

Breaking Changes

None. Telemetry is disabled by default and fully opt-in.

[vinitkadam03]

Still WIP. Would rebase on top of #833 as it fixes bugs and centralizes call tools.