Azure AI Foundryhttps://ai.azure.comMicrosoft's AI app platform. Vertex AI Agent Builderhttps://cloud.google.com/products/agent-builderGCP agent platform. AWS Bedrockhttps://aws.amazon.com/bedrockManaged multi-provider model service. Azure OpenAIhttps://azure.microsoft.com/products/ai-services/openai-serviceOpenAI models on Azure. Google Vertex AIhttps://cloud.google.com/vertex-aiGCP's managed model + agent platform.