Summary

The reports tools are the ones you will actually reach for.

Basecamp's own interface makes "what is assigned to this person everywhere" and "what is overdue across all projects" into a lot of clicking; here each is one call. Know one limit before you rely on the file tools: the project's own compatibility note says Claude Code passes PDF blobs through to the model, while Claude Desktop and claude.ai currently reject non-image embedded resources — the bytes reach the host and stop there. Use the CLI client when you need a document read.

What it is

A FastMCP server for Basecamp 3 that covers most of the product rather than a slice of it — projects, to-dos, message boards, campfires, card tables, inbox forwards, documents, uploads, comments, events, webhooks and search — authenticated through an OAuth application you create yourself.

What you get

Projects and search: `get_projects`, `get_project`, `search_basecamp`, `global_search`
Cross-project reports, which is where it beats clicking: `get_person_assignments` returns everything assigned to one person across all projects, `get_overdue_todos` returns overdue items grouped by lateness, `get_assignable_people` lists who can be assigned
To-dos: `get_todolists`, `create_todolist`, `get_todos`, `create_todo`, `update_todo`, `complete_todo`, `reposition_todo`, `create_todolist_group`
Card tables: `get_card_tables`, `get_columns`, `create_column`, `put_column_on_hold`, `get_cards`, `create_card`, `move_card`, `create_card_step`, `complete_card_step`
Messages and documents, drafts included: `get_messages`, `create_message`, `create_draft_message`, `get_documents`, `create_document`, `create_draft_document`, `get_comments`, `create_comment`
Files that reach the model: `download_upload` and `download_attachment` return the bytes as MCP content rather than a link
Events and webhooks: `get_events`, `get_webhooks`, `create_webhook`, `delete_webhook`
Config generators for Codex, Cursor and Claude Desktop, so the client entry is written for you

Requirements

Python 3.10 or newer, a Basecamp 3 account, and your own OAuth application from launchpad.37signals.com. `BASECAMP_CLIENT_ID`, `BASECAMP_CLIENT_SECRET`, `BASECAMP_ACCOUNT_ID` and a `USER_AGENT` string go into `.env`, then `python oauth_app.py` runs the browser flow on `http://localhost:8000` and stores the token in `oauth_tokens.json`. If your system Python is older, `uv venv --python 3.12` is the documented way around it.