Safe updates

Every presentation read includes a checksum representing the version you received. update_presentation requires that checksum.

Read–edit–update

1. Call get_presentation immediately before editing.
2. Preserve the returned checksum.
3. Modify the returned source.
4. Call update_presentation with the presentation ID, complete updated source, and checksum.
5. Read the presentation again to confirm the published result.

get_presentation → edit source → update_presentation(checksum) → get_presentation

Conflict response

If somebody or another client saves the deck after your read, the update returns CONFLICT. This is protection against silently overwriting their work.

Do not retry the same update blindly. Read the current presentation, compare the new source with your intended change, reapply the edit, and submit the new checksum.

Caution

update_presentation replaces the editable source. Give the client a precise instruction about what must remain unchanged, especially when speaker notes, citations, or custom layout directives are present.