Universal Containers wants to use an external large language model (LLM) in Prompt Builder. What should An Agentforce recommend?

The officially sanctioned method for integrating an external Large Language Model (LLM) for use within Prompt Builder is the Bring Your Own LLM (BYO-LLM) functionality available in Einstein Studio. This feature allows administrators to register and deploy models from third-party providers (e.g., via Amazon SageMaker or Google Vertex AI). Once the external model is configured in Einstein Studio, it becomes a selectable option directly within the Prompt Builder interface. This enables users to declaratively create and manage prompt templates that leverage the external model, while still benefiting from the platform's integrated features like the Einstein Trust Layer for data masking and governance.

A. Use Apex to connect to an external LLM and ground the prompt.

This is a programmatic workaround. It does not make the external LLM available as a declarative, selectable option within the Prompt Builder user interface.

C. Use Flow and External Services to bring data from an external LLM.

This approach bypasses Prompt Builder entirely. It uses a different automation tool (Flow) to call the LLM, rather than integrating the model into the Prompt Builder framework.

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1. Official Vendor Documentation: Salesforce Help

Einstein Studio

"Bring Your Own LLM to the Einstein Trust Layer".

Reference Section: The document states

"After you deploy a model in Einstein Studio

it’s available in Prompt Builder and in Apex for your users to experiment with." This directly confirms that configuring the model in Einstein Studio makes it available in Prompt Builder.

2. Official Vendor Documentation: Salesforce Help

Prompt Builder

"Create a Prompt Template".

Reference Section: In the setup steps for creating a prompt template

the documentation describes the "Select a Model" step. The list of available models explicitly includes custom models that have been registered via Einstein Studio

demonstrating the direct integration path.

3. Official Vendor Documentation: Salesforce Developers

Einstein 1 Platform for Developers

"Generative AI and the Einstein Trust Layer".

Reference Section: Under the "Bring Your Own Model (BYOM)" heading

the documentation explains: "The Einstein 1 Platform allows you to bring your own predictive and generative AI models... Once connected

these models are available in tools like Prompt Builder and Flow Builder." This reinforces that Einstein Studio's BYO-LLM capability is the designated integration point for tools like Prompt Builder.