Choose the right Domino surface

Domino shares product objects and domain rules across several interfaces. Supported operations, availability, and interaction mechanics vary by surface.

Decision table

Situation	Surface	What the assistant should do
The user is looking at letsdomino.io and asks where to click	Web	Give current UI instructions. Do not replace them with API calls.
The user is texting Domino or asks what to text	SMS	Give conversational examples and explain follow-up or exact confirmation.
The assistant has an authorized Domino MCP connection	MCP	Discover authorized tools, use typed inputs, and present typed outcomes.
A developer wants the integration to choose structured operations	Capability API	Use the generated OpenAPI schema and typed outcome contract.
A developer wants Domino to interpret conversational requests	Assistant API	Submit natural-language turns, preserve conversation identity, and handle returned outcomes.
The user asks only “How do I…?”	Usually web instructions	Explain first. Do not infer authorization to act.
The user explicitly asks a connected assistant to do it	MCP or API	Execute only within the granted abilities and stop at approval boundaries.

Outcome parity, not identical mechanics

“Create an Ideas List” can be one outcome across surfaces:

on web, the user selects Ideas, chooses defaults, and submits the form;
over SMS, Domino interprets the request conversationally and asks for missing information;
through MCP, the calling assistant selects and invokes the typed capability;
through the Capability API, the caller selects the operation and supplies structured input;
through the Assistant API, Domino interprets the conversational request and selects the supported operations.

Do not make the surfaces sound identical. They share domain rules and outcomes, not button labels, confirmation syntax, or transport behavior.

For a complete outcome comparison, use Feature support by surface. If the requested behavior is absent or partially supported, use Limits, unsupported behavior, and current boundaries rather than inferring parity.

Tell versus do

Classify the user's request before proceeding:

Explain: “How do I share this list?” Give instructions.
Prepare: “Get this ready to share.” Create only a reviewable draft or prepared action when connected and authorized.
Commit: “Send the reviewed invitation now.” Commit only if the relevant surface has a current valid approval.

When uncertain whether the user wants an explanation or an account mutation, ask one direct question. Do not turn a documentation question into a write.

Surface boundaries

Web

The user owns every click. Point to visible labels and explain the completion state. A web share-link flow can create a link without sending it through the user's outside messaging app.

SMS

Domino owns conversational interpretation and durable continuation. Exact control messages can have special meaning. An entire eligible message equal to SEND is the external-send confirmation; “yes,” “send it,” punctuation, and extra text are not equivalent.

MCP

The calling assistant owns natural-language interpretation and tool selection. Domino validates and executes authorized typed operations without taking over the conversation. Individual capabilities, such as capture or idea generation, may still perform their own model work. Use handles and returned next actions rather than internal IDs; see the MCP guide for the research boundary.

API

The Capability API lets the caller choose operations and supply strict structured input. Writes require stable idempotency keys.

The Assistant API lets Domino interpret natural-language requests and maintain conversational state. Clients use a stable conversation identity and a unique request key for each turn.

Both can return work that requires polling. Prepared actions require later explicit approval through the appropriate commit path: a capability commit for the Capability API, or the dedicated prepared-action endpoint for the Assistant API. Follow the API guide for authentication, status handling, and confirmation details.

LLM answering guidance

State which surface your answer applies to.
If the user switches surfaces, fetch the new surface guide.
Never instruct an API or MCP caller to use SMS SEND as its approval protocol.
Never imply that reading a guide grants access to a Domino account.