Lineup Markers

July 21, 2026 ยท View on GitHub

Endpoints:

List markers

  • GET /lineup/markers.json returns all markers for the account.

This endpoint will return 200 OK with a JSON array of markers.

Example JSON Response
[
  {
    "id": 6750828,
    "created_at": "2026-07-21T00:21:46.309Z",
    "date": "2026-04-06",
    "name": "Spring kickoff",
    "updated_at": "2026-07-21T00:21:46.309Z"
  }
]
Copy as cURL
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -H "Content-Type: application/json" \
  https://3.basecampapi.com/$ACCOUNT_ID/lineup/markers.json

Create a marker

  • POST /lineup/markers.json creates an account-wide marker that shows up in the Lineup.

Required parameters:

  • name of the marker.
  • date of the marker ISO 8601 formatted without a time part.

This endpoint will return 201 Created with an empty response body.

Example JSON Request
{
  "name": "Anniversary",
  "date": "2021-01-01"
}
Copy as cURL
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -H "Content-Type: application/json" \
  -d '{"name": "Anniversary", "date": "2021-01-01"}' \
  https://3.basecampapi.com/$ACCOUNT_ID/lineup/markers.json

Update a marker

  • PUT /lineup/markers/1.json changes name and/or date of the marker with an ID of 1.

Optional parameters:

  • name of the marker.
  • date of the marker ISO 8601 formatted without a time part.

This endpoint will return 200 OK with an empty response body.

Example JSON Request
{
  "name": "Updated anniversary"
}
Copy as cURL
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -H "Content-Type: application/json" \
  -d '{"name": "Updated anniversary"}' -X PUT \
  https://3.basecampapi.com/$ACCOUNT_ID/lineup/markers/1.json

Destroy a marker

  • DELETE /lineup/markers/1.json permanently destroys the marker with an ID of 1 immediately.

This endpoint will return 204 No Content.

Copy as cURL
curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -H "Content-Type: application/json" \
  -X DELETE \
  https://3.basecampapi.com/$ACCOUNT_ID/lineup/markers/1.json