Description:

Adds the AIProviders plugin, which gives Matomo a shared server-side integration layer for AI features. It supports Anthropic, OpenAI, Google, and OpenAI-compatible custom endpoints, with an admin UI for self-managed instances to configure credentials, default provider, model settings, and connection tests.

Other plugins should not call completion endpoints through API.php; those methods are only for the administration UI. Runtime use goes through AIProviderService:

• complete(new AIRequest($prompt, $callerPlugin)) for prompt-in/text-out or JSON responses.
• converse(new AIConversationRequest($messages, $callerPlugin)) for multi-turn conversations and tool-calling flows.

Requests use immutable request objects for:

• caller and feature metadata
• provider/model hints
• generation options such as max tokens and temperature
• JSON mode for simple completions
• optional site context for completion requests
• tool catalogs for conversation requests

Conversation messages use a provider-agnostic canonical shape, and each provider translates that shape to its own wire format. Responses expose text/content, provider/model metadata, token usage where available, stop reason, and timing.

Self-managed instances can configure providers in the UI or via server-side configuration. In a managed environment, provider configuration is locked server-side, the admin screen is hidden, and normal plugin requests are routed through the managed default provider. Provider/model selection is only honored for selected trusted server-side callers.

A custom provider can either be configured through the built-in Custom Provider option in the UI, using an OpenAI-compatible base URL plus an optional API key, or registered by another plugin via the AIProviders.addAIProviders event with a custom AIProvider class.

Includes unit and integration coverage for configuration resolution, managed-environment behavior, provider registration, completion requests, JSON responses, conversation support, and provider-specific request/response translation.

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done see checklist
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed