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MCP security and data handling

Understand Deckary MCP OAuth permissions, live sharing boundaries, model-provider data flow, write safeguards, and operational analytics.

Last verified: 2026-10-06

Deckary MCP uses OAuth and separates saved-deck access from live Office access. Saved decks are limited to the signed-in user's Deckary account. Live PowerPoint, Excel, and Word access requires a second permission plus an active, explicitly shared add-in session. Deckary validates versioned writes to reduce stale or duplicate changes.

OAuth permissions

The remote endpoint is https://deckary.com/mcp. It publishes OAuth protected-resource metadata and uses standards-based authorization challenges so compatible MCP clients can discover the authorization flow.

Deckary currently separates presentation access into these permissions:

PermissionEnables
decks:editDiscovery, reading, rendering, and authoring for the signed-in user's saved Web Builder decks
live-documents:editDiscovery, reading, inspection, rendering, and authoring for explicitly shared live PowerPoint presentations, Excel workbooks, and Word documents

Authorizing live access does not by itself expose every Office file on the computer. The add-in session for that file must also be active and sharing must be on.

What the external AI provider receives

Your AI client decides which MCP tools to call. Deckary receives those tool calls and returns the presentation data or slide images required by the call. The external AI provider can therefore receive content and images returned from the presentation you selected.

The provider's own privacy, retention, and training policies apply to information processed in that client. Deckary's connector does not automatically receive unrelated conversation history, model memory, or files that the client does not send through a tool call.

Saved and live data boundaries

Saved Web Builder presentation content is stored in your Deckary account as part of the browser product.

For a live session, the add-in observes and mutates the open Office document. Live content and renders used by the connector are processed in memory for the active request and session; the connector does not store the document in Deckary.

Read Deckary's current Privacy Policy for the governing service terms and broader data-handling details.

Write safeguards

  • Saved-deck authoring is bound to a current deck revision.
  • Live authoring requires the current session, connection generation, and expected artifact version.
  • The add-in captures fresh Office truth immediately before a live mutation.
  • A live version_conflict, a validation failure, or a preflight rejection makes zero mutation.
  • A successful live authoring result returns fresh state and exact committed Office pixels.
  • A settlement_unknown result must not be retried automatically.
  • Writes go through a validated program for each host. There is no path for raw Office.js, OOXML, or scripts.
  • In Excel, overwriting a non-empty cell must be requested explicitly. In Word, review tracked lets you accept or reject the agent's edits as tracked changes.
  • Protected live slide replacement and nonempty source bindings are not exposed through this MCP path.

These controls reduce stale writes, but the external agent still chooses the requested edit. Review the selected presentation, the requested scope, and the result before continuing with sensitive material.

Operational analytics

When analytics consent applies, Deckary records bounded operational facts such as tool name, duration, outcome, a bounded error classification, and byte or image counts. MCP analytics do not record deck or session IDs, titles, prompts, authoring programs, slide content, slide images, or raw error payloads.

End live access

Turn off MCP sharing in the Deckary add-in, sign out, or close the task pane to end that document's live session. You can also remove the Deckary connection from your AI client to stop that client from making new authenticated calls.