Merge API Documentation

Authentication: OAuth. See Magic Link for the runtime auth flow, or Application credentials to bring your own OAuth app.

Sample use cases

List every to-do assigned to me across all Basecamp projects, sorted by due date.
Post the standup summary from this morning’s huddle to the Engineering Internal campfire.
Find every overdue task in the Q2 Launch project and ping the owner.

Available Tools

list_comments

List all comments on a recording (todo, message, etc.). Returns paginated list of active comments.

get_comment

Get a specific comment by ID with full details including content and creator.

create_comment

Create a new comment on a recording (todo, message, etc.). Content must be HTML formatted.

update_comment

Update an existing comment’s content. Content must be HTML formatted.

list_people

List all people visible to the current user in the Basecamp account.

get_person

Get a specific person by ID with full profile details.

get_current_user

Get the current authenticated user’s profile.

get_project_people

Get all active people on a specific project.

list_projects

List all projects accessible to the user. Returns active projects by default. Use status to filter.

get_project

Get a specific project by ID with full details including dock items and tools.

create_project

Create a new project. Requires a name. Optional: description.

update_project

Update a project’s name and/or description.

list_schedule_entries

List all schedule entries in a schedule. Returns active entries by default. Use status to filter.

get_schedule_entry

Get a specific schedule entry by ID with full details including participants and recurrence.

create_schedule_entry

Create a new schedule entry. Requires summary, starts_at, and ends_at. Optional: description, participants.

update_schedule_entry

Update a schedule entry. All fields are optional - only provided fields will be updated.

list_todos

List todos in a todolist. Returns active pending todos by default. Use status/completed params to filter.

get_todo

Get a specific todo by ID with full details including assignees, dates, and completion status.

create_todo

Create a new todo in a todolist. Requires content (title). Optional: description, assignees, due date.

update_todo

Update a todo. Content is always required. Pass all fields you want to keep; omitted fields may be cleared.

complete_todo

Mark a todo as completed.

uncomplete_todo

Mark a completed todo as incomplete/pending again.

list_todolists

List all todolists in a todoset/project. Returns active lists by default. Use status to filter.

get_todolist

Get a specific todolist by ID with details including completion ratio and todo count. Optionally provide the ‘url’ field from list_todolists response for direct access.

create_todolist

Create a new todolist in a todoset.

update_todolist

Update a todolist name and description. Name is required and cannot be blank.