> ## Documentation Index > Fetch the complete documentation index at: https://docs.tilt.io/llms.txt > Use this file to discover all available pages before exploring further. # Choose an integration > Compare Tilt's built-in experience, Tilt Agent over MCP, and the index construction REST API design preview. Choose an integration based on who owns the interface and whether the input is a natural-language outcome or structured construction rules. | | Tilt | Tilt Agent over MCP | REST API design preview | | - | - | - | - | | Availability | Available | Available for authorized Tilt users | Not available | | Interface owner | Tilt | Your application | Your application | | Input | Chat and editable construction rules | A complete natural-language task, with optional Tilt context | Proposed structured requests | | Orchestration | Tilt manages the conversation and construction workflow | Tilt Agent executes the task; your application manages submission, progress, results, and follow-ups | Your application would coordinate each proposed API operation | | State and iteration | Tilt chats and saved Tilts | A durable Tilt Agent session with one run for each turn | Proposed Tilt IDs and revisions | | Presentation | Tilt's built-in views | Your host's model or Tilt's MCP App | Your interface | | Best fit | Use the complete Tilt experience | Add Tilt Agent to a chat or agent you operate | Review a deterministic construction API contract | ## Use Tilt directly Use Tilt when users can work in Tilt's chat and Tilt view. Tilt Agent can create or refine a Tilt from a description, while the Methodology and Portfolio tabs expose the resulting rules, constituents, and backtest. The [thematic Tilt guide](/index-construction/example-nuclear-energy) follows this workflow from the first request through a rule change. ## Delegate to Tilt Agent over MCP Use MCP when your application owns the chat or agent experience and should delegate investment work to Tilt Agent. Your host sends one complete task, such as creating a rules-based nuclear energy Tilt, rather than translating the task into a sequence of construction API calls. Delegation is asynchronous. The first tool call returns a run ID and a durable session ID. Your host reads progress and structured output from the run, then reuses the session ID for follow-up turns. Tilt Agent can research, ask for missing input, and use the same construction capabilities available in Tilt. A model-driven MCP host can interpret the structured output and answer through its native interface. For a full interactive renderer, use Tilt's MCP App; Tilt can also customize that experience for a third-party integration. Tilt is exploring additional custom rendering options. Contact Tilt to discuss a specific integration. The standard connection is authorized by a Tilt user account and currently runs in that user's personal Tilt organization. Each host user needs a separate authorized connection. Custom identity, organization, or single sign-on arrangements are outside the standard connection flow. MCP delegates complete tasks to Tilt Agent. The REST design preview accepts individual structured operations. A delegated run can return clarification or explanatory output as well as saved work. Index publication remains a separate review process after Tilt creation or changes. Authorize a connection, delegate a task, consume its result, and continue the same Tilt Agent session. ## Review the REST API design The REST design preview describes proposed resources for clients that already have structured construction rules and want deterministic create, apply, constituent, and backtest operations. It excludes natural-language construction and Tilt Agent does not participate in the workflow. The endpoints are not available. Use the preview to evaluate the proposed contract, not to build a production integration. Review the proposed resources and workflow.