Basecamp

Full CLI coverage: 189 tracked in-scope endpoints across todos, cards, messages, files, schedule, check-ins, timeline, recordings, templates, webhooks, subscriptions, lineup, chat, pings, gauges, assignments, notifications, and accounts.

Agent Invariants

MUST follow these rules:

1. Choose the right output mode — --jq when you need to filter/extract data; --json for full JSON; --md when presenting results to a human (see Output Modes below). Never pipe to external jq — use --jq instead.

2. Parse URLs first with basecamp url parse "<url>" to extract IDs

3. Comments are flat - reply to parent recording, not to comments

4. Check context via .basecamp/config.json before assuming project

5. Content fields accept Markdown and @mentions — message body and comment content accept Markdown syntax; the CLI converts to HTML automatically. Use Markdown formatting (lists, bold, links, code blocks, tables) for rich content. Four mention syntaxes are available (prefer deterministic for agents):

   • [@Name](mention:SGID) — zero API calls, embeds SGID directly (preferred for agents)
   • [@Name](person:ID) — one API call, resolves person ID to SGID via pingable set
   • @sgid:VALUE — inline SGID embed for pipeline composability
   • @Name / @First.Last — fuzzy name resolution (may be ambiguous) For todos, documents, and cards, content is sent as-is — use plain text or HTML directly.

   Table boundary: GFM tables round-trip: they render in message/comment bodies, display converts them back to pipe tables, and the TUI in-place editors open simple grids for editing. Only complex tables — merged cells (colspan/rowspan), captions, extra header rows, nested tables, attachments/images or block content inside cells, multi-paragraph or multi-line cells, or a table inside a blockquote or list — refuse to open, since a GFM pipe table can't represent those shapes (edit them on Basecamp web, or replace the whole field via messages update / comments update / todos update --description, which take fresh content and are unaffected). Complex tables still display best-effort, flattened to a plain grid.

   Multiline / non-ASCII content: do not rely on bash ANSI-C quoting ($'...\n...') — it is a bash/zsh extension. Under a POSIX /bin/sh (dash, busybox-ash, common in sandboxes) the $ is passed through literally and posts a stray leading $, and \n stays a literal backslash-n. Pipe the content via stdin instead, using - as the content argument:

   printf '%s\n' '海报 mockup 方向稿：' '' '<bc-attachment ...>' | basecamp comments create <recording_id> - --in <project> --json
   

   - means "read from stdin" on every content input: content-kind positionals (comments create/update, messages create [body], cards create [body], todos create, docs documents create [content], chat post/update, boost create, checkins answer create/update, notes set) and content flags (--data on api post/put, --body, --content, --description, --comment on todos sweep, --file on notes set). Each command's --agent help lists its stdin inputs. Rules:

   • A pipe is never consumed implicitly — without - it is ignored (or, where content is required and missing, the error teaches -).
   • Only one input can read stdin per invocation.
   • A literal - anywhere else (a title, a name, a path) errors when stdin is piped. Escape a positional after the -- separator (basecamp projects create -- -); a flag value has no in-line escape — run the command without piped stdin. basecamp help and shell completion are exempt: they write nothing to Basecamp, and completion legitimately receives - as the word being completed.
   • - with nothing piped (interactive TTY) errors immediately instead of hanging; use a pipe, a heredoc (basecamp comments create <id> - <<'EOF'), or --edit where offered.
   • Trailing newlines are trimmed from stdin content, so printf 'x\n' | ... - posts x (this keeps boost create - inside its 16-rune limit).

6. Project scope is mandatory for most commands — via --in <project> or .basecamp/config.json. Cross-project exceptions: basecamp reports assigned for assigned work, basecamp assignments for structured assignment views, basecamp reports overdue for overdue todos, basecamp reports schedule for upcoming schedule across all projects, basecamp recordings <type> for browsing by type, basecamp notifications for notifications, basecamp gauges list for account-wide gauges, and the seven list commands covered in item 7.

7. Account-wide listing. basecamp todos list --all-projects --json lists across every project; the same flag does the same on cards list, messages list, comments list, files list, forwards list, and checkins answers. It overrides a configured project, and with no project in scope those commands already list account-wide rather than prompting. Flags that name something inside a single project are rejected there rather than silently ignored. Account-wide listings return the first 100 items by default — account-wide "all" is the whole account, not one project's worth. Use --limit N to raise the cap (it walks pages until N are collected) or --all for everything. --page N fetches exactly one page, but only on the paginated listings. The two overdue variants — basecamp todos list --all-projects --overdue and basecamp cards list --all-projects --overdue — come from unpaginated endpoints. They accept --limit and --all but reject --page, so do not generate --page against them.

Output Modes

Choosing a mode:

| Goal | Flag | Format | |------|------|--------| | Filter/extract JSON data | --jq '<expr>' | Built-in jq filter (no external jq needed). Implies --json; filter runs on the envelope. | | Filter in agent mode | --agent --jq '<expr>' | Filter runs on data-only payload (no envelope), matching --agent contract. | | Full JSON output | --json | JSON envelope: {ok, data, summary, breadcrumbs, meta}; errors: {ok:false, error, code, retryable, hint, meta} | | Show results to a user | --md / -m | GFM tables, task lists, structured Markdown | | Automation / scripting | --agent | Success: raw JSON data (no envelope); errors: {ok:false,...} object; no interactive prompts |

Always pass --json or --md explicitly — auto-detection depends on config and may not produce the format you expect. Use --md when composing reports, summarizing data, or displaying results inline. --agent is for headless integration scripts.

Avoiding interactive prompts. The flags --agent/--json/--quiet/--ids-only/--count and the environment variable BASECAMP_NONINTERACTIVE=1 suppress interactive selection prompts. --md does not — if a required target is ambiguous (e.g. a project with multiple todosets and no --todoset), and the CLI is attached to a terminal, it will show a blocking picker. When you need Markdown output and no prompts, either pass the flag that names whatever is ambiguous (--todoset <id> for the todoset case above, or --in <project> / --list <id> when the project or list is ambiguous) or set BASECAMP_NONINTERACTIVE=1 in the environment. BASECAMP_NONINTERACTIVE disables all prompts (they become actionable errors instead) without changing the output format — an escape hatch for agents running under a PTY.

Other modes: --quiet (success: raw JSON, no envelope; errors: {ok:false,...}), --ids-only, --count, --stats (session statistics), --styled (force ANSI), -v / -vv (verbose/trace), --jq '<expr>' (built-in jq filter — see below).

CLI Introspection

Navigate unfamiliar commands with --agent --help — returns structured JSON describing any command:

basecamp todos --agent --help

{"command":"todos","path":"basecamp todos","short":"...","long":"...","usage":"...","notes":["..."],
 "subcommands":[{"name":"sweep","short":"...","path":"basecamp todos sweep"}],
 "flags":[{"name":"assignee","type":"string","default":"","usage":"..."}],
 "inherited_flags":[{"name":"json","shorthand":"j","type":"bool","default":"false","usage":"..."}]}

Walk the tree: start at basecamp --agent --help for top-level commands, then drill into any subcommand. Commands carry domain-specific agent hints (e.g., "--assignee filters the account-wide listing only; within a project, fetch all and filter client-side").

Pagination

basecamp <cmd> --limit 50   # Cap results (default varies by resource)
basecamp <cmd> --all        # Fetch all (may be slow for large datasets)
basecamp <cmd> --page 1     # First page only, no auto-pagination

--all and --limit are mutually exclusive. --page cannot combine with either.

Smart Defaults

• --assignee me resolves to current user
• --due tomorrow / --due +3 / --due "next week" — natural date parsing, when setting a due date (todos create, todos update, cards create, and so on)
• --due on a listing is a different flag and does not take dates: it accepts only with, without, or overdue, and only account-wide. basecamp todos list --due tomorrow is rejected. For date-based listing use --overdue, --no-due-date, or basecamp assignments due <scope>
• Project from .basecamp/config.json if --in not specified
• Multiple identities use named profiles: basecamp profile create <name>, then select one with global --profile <name> or BASECAMP_PROFILE=<name>.

Quick Reference

Note: Most queries require project scope (via --in <project> or .basecamp/config.json). Cross-project exceptions: basecamp reports assigned, basecamp assignments, basecamp reports overdue, basecamp reports schedule, basecamp recordings <type>, basecamp notifications, basecamp gauges list.

Seven list commands also list account-wide: basecamp todos list --all-projects --json, and likewise cards list, messages list, comments list, files list, forwards list, and checkins answers.

| Task | Command | |------|---------| | List projects | basecamp projects list --json | | My todos (in project) | basecamp todos list --assignee me --in <project> --json | | My todos (cross-project) | basecamp reports assigned --json (defaults to "me") | | My schedule (cross-project) | basecamp reports schedule --json (upcoming events across all projects) | | All todos (cross-project) | basecamp todos list --all-projects --json (grouped by project) | | Overdue todos (in project) | basecamp todos list --overdue --in <project> --json | | Overdue todos (cross-project) | basecamp todos list --all-projects --overdue --json (flat, oldest first) or basecamp reports overdue --json (bucketed by lateness) | | All cards (cross-project) | basecamp cards list --all-projects --json (grouped by project) | | Someone's todos (cross-project) | basecamp todos list --all-projects --assignee "Ann" --json (server-side filter) | | Two people's todos (cross-project) | basecamp todos list --all-projects --assignee ann --assignee bob --json (matches either) | | Someone's cards (cross-project) | basecamp cards list --all-projects --assignee "Ann" --json | | Todos with no due date set (cross-project) | basecamp todos list --all-projects --due without --json | | My bookmarks | basecamp bookmarks list --json | | Bookmark something | basecamp bookmarks add <id-or-url> --json | | Is it bookmarked? | basecamp bookmarks check <id-or-url> --json (always exits 0) | | Bubble a recording up | basecamp bubble-up add <id-or-url> --json | | Schedule a bubble-up | basecamp bubble-up add <id-or-url> --at tomorrow --json | | Pop a bubble-up | basecamp bubble-up remove <id-or-url> --json | | My unpublished drafts | basecamp drafts list --json | | Read my personal note | basecamp notes show --json | | Replace my personal note | basecamp notes set "<content>" --json | | Check-ins I owe answers to | basecamp checkins reminders --json | | Add to Up Next | basecamp assignments prioritize <id> --json | | Recolor a calendar | basecamp calendars update <id-or-url> --color blue --json | | Todo outside any list | basecamp todos create "<content>" --loose --in <project> --json | | Assign todo | basecamp assign <id> [id...] --to <person> --in <project> --json | | Assign card | basecamp assign <id> [id...] --card --to <person> --in <project> --json | | Assign card step | basecamp assign <id> [id...] --step --to <person> --in <project> --json | | Create todo | basecamp todos create "Task" --in <project> --list <list> --json | | Create todolist | basecamp todolists create "Name" --in <project> --json | | Complete todo | basecamp todos complete <id> --json | | List cards | basecamp cards list --in <project> --json | | Create card | basecamp cards create "Title" --in <project> --json | | Complete card | basecamp cards done <id|url> --in <project> --json | | Move card | basecamp cards move <id> --to <column> [--position N] --in <project> --json | | Move card to on-hold | basecamp cards move <id> --on-hold --in <project> --json | | Move card to another project | basecamp cards move <id> --to-wormhole <wormhole_id> --in <project> --json (async teleport) | | Post message | basecamp messages create "Title" "Body" --in <project> --json | | Post with @mention | basecamp messages create "Title" "Hey @First.Last, ..." --in <project> --json | | Post silently | basecamp messages create "Title" "Body" --no-subscribe --in <project> --json | | Post to chat | basecamp chat post "Message" --in <project> --json | | List pings | basecamp notifications --json --jq '.data.reads[]? | select(.section == "pings")' | | Read ping thread | basecamp api get "/buckets/<circle_id>/chats/<chat_id>/lines.json" --agent | | Post to ping thread | basecamp api post "/buckets/<circle_id>/chats/<chat_id>/lines.json" --data '{"content":"<p>message</p>"}' --json | | Add comment | basecamp comments create <recording_id> "Text" --in <project> --json | | Inspect comment / reply atoms | basecamp comments show <url> --json → reply_target + mention in .data | | List attachments | basecamp attachments list <id\|url> --json | | Download attachments | basecamp attachments download <id> --out /tmp/ | | Show + download | basecamp todos show <id> --download-attachments --json | | Stream attachment to stdout | basecamp attachments download <id> --file <name> --out - | | Change history for an item | basecamp events <id\|url> --json (when a card moved columns, when a todo was completed) | | Search | basecamp search "query" --json | | Parse URL | basecamp url parse "<url>" --json | | Upload file | basecamp files uploads create <file> [--vault <folder_id>] --in <project> --json | | Download file | basecamp files download <id> --in <project> | | Stream file to stdout | basecamp files download <id> --out - --in <project> | | Download storage URL | basecamp files download "https://storage.3.basecamp.com/.../download/report.pdf" | | My assignments | basecamp assignments --json (priorities + non-priorities) | | Overdue assignments | basecamp assignments due overdue --json | | Completed assignments | basecamp assignments completed --json | | Notifications | basecamp notifications --json | | Mark notification read | basecamp notifications read <id> --json | | All bubble-ups (BC5) | basecamp notifications bubbleups --json | | Gauges (account-wide) | basecamp gauges list --json | | Gauge needles | basecamp gauges needles --in <project> --json | | Create needle | basecamp gauges create --position 75 --color green --in <project> --json | | Account details | basecamp accounts show --json |

URL Parsing

Parse URLs before acting on them — unless you're handing the URL to a command that accepts a URL directly (show, comments show, comments thread, attachments list/attachments download), which extract the IDs for you. Only comments show and comments thread verify the URL's host and account before any fetch. For other URL-accepting commands, only pass URLs from a trusted Basecamp host: basecamp url parse extracts IDs but does not validate the URL's origin, so parsing an attacker-controlled path yields trusted-looking IDs.

basecamp url parse "https://3.basecamp.com/2914079/buckets/41746046/messages/9478142982#__recording_9488783598" --json

Returns: account_id, project_id, type, recording_id, comment_id (from fragment).

URL patterns:

• /buckets/27/messages/123 - Message 123 in project 27
• /buckets/27/messages/123#__recording_456 - Comment 456 on message 123
• /buckets/27/card_tables/cards/789 - Card 789
• /buckets/27/card_tables/columns/456 - Column 456 (for creating cards)
• /buckets/27/todos/101 - Todo 101
• /buckets/27/uploads/202 - Upload/file 202
• /buckets/27/documents/303 - Document 303
• /buckets/27/schedule_entries/404 - Schedule entry 404

Replying to comments:

# Comments are flat - reply to the parent recording_id, not the comment_id
basecamp url parse "https://...messages/123#__recording_456" --json
# Returns recording_id: 123 (parent), comment_id: 456 (fragment) - comment on 123, not 456
basecamp comments create 123 "Reply" --in <project>

# Or get the whole reply-ready context deterministically in one call:
basecamp comments thread "https://...messages/123#__recording_456" --json
# .data.reply_target.recording_id  → where to post the reply
# .data.reply_target.account_id    → the account that reply belongs to (build a fully-qualified command)
# .data.focus.author.mention.syntax → paste-ready [@Name](mention:SGID)
# .data.comments                   → surrounding discussion (default window of 41)
# --all returns every fetched comment; --window N sets the window size
# When the account came from the URL (none configured), the reply breadcrumb carries --account

Decision Trees

Finding Content

Need to find something?
├── Know the type + project? → basecamp <type> list --in <project> --json
│   (some groups have default list behavior; use --agent --help if unsure)
├── My assigned work? → basecamp assignments --json (priorities + non-priorities)
│   Or: basecamp reports assigned --json (traditional view, defaults to "me")
├── My overdue assignments? → basecamp assignments due overdue --json
├── My notifications? → basecamp notifications --json
├── Upcoming schedule? → basecamp reports schedule --json (cross-project)
├── Overdue across projects? → basecamp reports overdue --json
├── Browse by type cross-project? → basecamp recordings <type> --json
│   (types: todos, messages, documents, comments, cards, uploads)
│   Note: Defaults to active status; use --status archived for archived items
│   ⚠ No assignee data — cannot filter by person; use reports assigned instead
├── Full-text search? → basecamp search "query" --json
├── Have a comment URL, or a notification link targeting a comment? → basecamp comments thread <url> --json
└── Have a URL? → basecamp url parse "<url>" --json

Modifying Content

Want to change something?
├── Have URL? → basecamp url parse "<url>" → use extracted IDs
├── Have ID? → basecamp <resource> update <id> --field value
├── Change status? → basecamp recordings trash|archive|restore <id>
├── Complete todo? → basecamp todos complete <id>
├── Complete card? → basecamp cards done <id|url> --in <project>
└── Reply to a comment? → basecamp comments show <url> --jq '.data | {reply_target, mention}'
    (one call, cheap atoms — the mention is machine-only, so use --jq/--json, not plain show)
    or basecamp comments thread <url> when you need the surrounding discussion;
    then basecamp comments create <reply_target.recording_id> <text>

Common Workflows

Link Code to Basecamp Todo

# Get commit info and comment on todo (use printf %q for safe quoting)
COMMIT=$(git rev-parse --short HEAD)
MSG=$(git log -1 --format=%s)
basecamp comments create <todo_id> "Commit $COMMIT: $(printf '%s' "$MSG")" --in <project>

# Complete when done
basecamp todos complete <todo_id>

Track PR in Basecamp

# Create todo for PR work
basecamp todos create "Review PR #42" --in <project> --assignee me --due tomorrow

# When merged
basecamp todos complete <todo_id>
basecamp chat post "Merged PR #42" --in <project>

Bulk Process Overdue Todos

# Preview overdue todos
basecamp todos sweep --overdue --dry-run --in <project>

# Complete all with comment
basecamp todos sweep --overdue --complete --comment "Cleaning up" --in <project>

Mentioning people (preferred — deterministic)

# 1. Look up the person
basecamp people pingable --jq '.data[] | select(.name == "Jane Smith")'
# => {"id": 42000, "attachable_sgid": "BAh7CEkiCG...", "name": "Jane Smith"}

# 2. Use SGID in Markdown mention syntax (zero API calls during post)
basecamp comments create 123 "Hey [@Jane Smith](mention:BAh7CEkiCG...), check this" --in <project>

# Or use person ID (one lookup during post)
basecamp comments create 123 "Hey [@Jane Smith](person:42000), check this" --in <project>

Mentioning people (interactive — may be ambiguous)

# Fuzzy matching: use @First.Last to reduce ambiguity
basecamp comments create <id> "@Jane.Smith, please review this" --in <project>
basecamp messages create "Update" "cc @Jane, @Alex" --in <project>
basecamp chat post "@Jane, done!" --in <project>

# Ambiguous names return an error with suggestions
# Use @First.Last for disambiguation

Move Card Through Workflow

# List columns to get IDs
basecamp cards columns --in <project> --json

# Complete a card (moves it to the Done column automatically)
basecamp cards done <card_id> --in <project>

# Move card to column
basecamp cards move <card_id> --to <column_id> --in <project>

# Move card to specific position in column (1-indexed)
basecamp cards move 

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