Bulk delete milestones

POST/api/v2/workspaces/{slug}/projects/{project_id}/milestones/bulk-delete/

Delete up to 50 milestones in one request. Each row goes through the same path as a single Delete a milestone, so delete guards still apply per row.

200 does not mean every row succeeded

By default this endpoint reports partial success: it answers 200 whenever the batch was processed, even if some rows failed. Read failed and the per-row results rather than branching on the status code alone.

If you want all-or-nothing instead, send all_or_none: true and treat 409 as the failure signal.

Path Parameters

slug:requiredstring

The workspace slug. It appears in your Plane URLs — in https://app.plane.so/my-team/projects/, the slug is my-team.

project_id:requiredstring (uuid)

The project the milestones belong to. Accepts the project UUID or its bare identifier, for example ENG.

Body Parameters

ids:requiredarray of string (uuid)

The ids of the milestones to delete. Between 1 and 50 per call. A value that isn't a UUID is a 400 for the whole envelope, not a failed row.

all_or_none:optionalboolean

Defaults to false. Leave it off for partial success: each row runs in its own savepoint, successful rows commit, and you read the breakdown.

Set it to true to make the batch atomic. Every row is still evaluated, but if any row fails the whole batch is discarded and the call answers 409 instead of the 200 envelope. Side effects scheduled by the rows follow the same outcome.

Scopes

projects.milestones:write

Errors

Status	Code	Cause
400	invalid_request	The envelope itself is malformed — ids missing or empty, more than 50 rows, or a non-UUID id.
401	unauthorized	Missing or invalid credentials.
403	forbidden	Your role or token scope can't write milestones in this project.
404	not_found	No such workspace or project, or it's outside your tenant.
406	not_acceptable	The Accept header asks for a representation the API can't produce.
409	conflict	An all_or_none: true batch had at least one failing row, so the whole batch was discarded.
413	payload_too_large	The request body is over the size limit.
415	unsupported_media_type	The body wasn't JSON. These routes are JSON-only — a form or multipart body can't express ids.
429	rate_limited	Throttled. Honor the Retry-After header before retrying.

Bulk delete milestones

curl -X POST \
  "https://api.plane.so/api/v2/workspaces/my-team/projects/4af68566-94a4-4eb3-94aa-50dc9427067b/milestones/bulk-delete/" \
  -H "X-Api-Key: $PLANE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "ids": [
    "b7e42a19-3c5d-4f80-9a26-8d1c0f4e7b53",
    "9c1f0b3d-6d2e-4c9a-8b41-2f7e5a0d6c88"
  ]
}'

import requests

response = requests.post(
    "https://api.plane.so/api/v2/workspaces/my-team/projects/4af68566-94a4-4eb3-94aa-50dc9427067b/milestones/bulk-delete/",
    headers={"X-Api-Key": "your-api-key"},
    json={
    "ids": [
        "b7e42a19-3c5d-4f80-9a26-8d1c0f4e7b53",
        "9c1f0b3d-6d2e-4c9a-8b41-2f7e5a0d6c88"
    ]
},
)
body = response.json()
print(body["succeeded"], body["failed"])

const response = await fetch(
  "https://api.plane.so/api/v2/workspaces/my-team/projects/4af68566-94a4-4eb3-94aa-50dc9427067b/milestones/bulk-delete/",
  {
    method: "POST",
    headers: {
      "X-Api-Key": "your-api-key",
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      ids: ["b7e42a19-3c5d-4f80-9a26-8d1c0f4e7b53", "9c1f0b3d-6d2e-4c9a-8b41-2f7e5a0d6c88"],
    }),
  },
);
const body = await response.json();
console.log(body.succeeded, body.failed);

Response200

{
  "results": [
    {
      "index": 0,
      "result": "deleted",
      "id": "b7e42a19-3c5d-4f80-9a26-8d1c0f4e7b53"
    },
    {
      "index": 1,
      "result": "failed",
      "type": "not_found",
      "code": "not_found",
      "detail": "No milestone matches the given query."
    }
  ],
  "succeeded": 1,
  "failed": 1
}

Response409

{
  "type": "conflict",
  "code": "conflict",
  "detail": "No rows were written because all_or_none was set and at least one row failed.",
  "errors": [
    {
      "field": "ids.1",
      "code": "not_found",
      "message": "No milestone matches the given query."
    }
  ]
}

Reading the response

The 200 envelope has three members:

• results — one row per input row, in request order, each carrying its index
• succeeded / failed — counts, so you can branch without walking the array

A succeeded row is { index, result, id } where result is deleted. A failed row keeps the same members as a top-level error body — type, code, detail and, on validation failures, errors[] — plus index and result: "failed". So the same error-handling code works per row as at the top level. See Errors.

Atomic batches

With all_or_none: true, every row is still evaluated — you get the full picture of what would have failed, not just the first problem — and then the batch is rolled back. The 409 body's errors[] entries are prefixed with the row index, as ids.<index>, so you can map each complaint back to the row that caused it.

Because the rollback covers the whole batch, side effects scheduled on commit — activity feed entries, webhooks — are discarded with it.

Limits and related routes

• 50 rows per call, and at least 1. Exceeding the cap is a 400 for the whole envelope.
• JSON only. A form or multipart body can't express ids, so these routes reject it with 415 rather than silently misreading the payload.
• Reconciling on external ids is not bulk's job. Use Upsert a milestone per row, or list and diff.
• ?fields= does not apply here — the response is a per-row result envelope, not a milestone body. See Sparse fields.