# POST /api/v2/workflow-transitions

Create a workflow transition

- MCP id: workflow-transitions.store
- Scope: api:write:workflows
- Permission: workflows::create
- Needs the sprints feature on your organisation
- Rate cost: 1 unit, write bucket. A write costs the same whatever `view` you ask for.
- Cache-Control: private, no-store

Adds a legal status move to a workflow and returns it with a `Location` header, mirroring the "add transition" action in plnnrly.

Both statuses must belong to the workflow named in `workflow_id`, and they must differ; a status from another workflow is refused as if it did not exist. The three ids are validated together, so an unusable `workflow_id` also fails both status fields. Duplicate edges are legal, exactly as they are in plnnrly. The work-item transition endpoint accepts the new move as soon as this call returns.

## Parameters
- view (string, optional): Which field set to render.
- X-Request-Id (header, optional): A correlation id of your own. It is recorded in our logs next to the server's request id but never returned: the response header always carries the server's id. A value that does not match the pattern is discarded silently, never rejected.
- Idempotency-Key (header, optional): A caller-chosen key that makes this POST safe to retry. Replaying it returns the original response with Idempotency-Replayed: true.

## Request body
- workflow_id (integer → Workflow.id, required): Workflow this edge belongs to. Both statuses belong to the same workflow, and the edge cannot be moved to another one.
- from_status_id (integer → WorkflowStatus.id, required): Status a work item must currently be in for this edge to apply.
- to_status_id (integer → WorkflowStatus.id, required): Status the work item moves to. Always different from `from_status_id`. Must differ from from_status_id.
- name (string ≤ 255, required): Transition label as shown on the status button, e.g. `Start progress`.

Unknown keys are refused with `422` validation-failed, naming the key.

## Response 201
- id (integer, required): Unique identifier.
- workflow_id (integer, required): Workflow this edge belongs to. Both statuses belong to the same workflow, and the edge cannot be moved to another one.
- from_status_id (integer, required): Status a work item must currently be in for this edge to apply.
- to_status_id (integer, required): Status the work item moves to. Always different from `from_status_id`.
- name (string ≤ 255, required): Transition label as shown on the status button, e.g. `Start progress`.
- created_at (timestamp (YYYY-MM-DDThh:mm:ssZ), required): Creation timestamp.
- updated_at (timestamp (YYYY-MM-DDThh:mm:ssZ), required): Last-write timestamp; use for incremental sync.
- workflow (Ref or WorkflowSummary, required): Workflow this edge belongs to.
- from_status (Ref or WorkflowStatusSummary, required): Status the edge leads out of.
- to_status (Ref or WorkflowStatusSummary, required): Status the edge leads into.
- links (WorkflowTransitionLinks, required)
  - self (url, required): The canonical URI of this record.

## Errors
- 403 forbidden-by-policy | insufficient-permission | insufficient-token-scope: Forbidden.
- 409 idempotency-key-in-flight | idempotency-key-reused: Conflict.
- 415 unsupported-media-type: Unsupported media type.
- 422 unprocessable-relationship | validation-failed: Unprocessable content.
- 400 idempotency-key-required | invalid-cursor | invalid-query-parameter | malformed-request | unsupported-parameter: Bad request.
- 401 token-expired | unauthenticated: Unauthenticated.
- 404 endpoint-not-found | resource-not-found: Not found.
- 406 not-acceptable: Not acceptable.
- 429 rate-limit-exceeded: Too many requests.
- 500 internal-error: Server error.
- 503 tenant-unavailable: Service unavailable.

## Example
```bash
curl -X POST \
  'https://<your-url>/api/v2/workflow-transitions' \
  -H 'Authorization: Bearer <token>' \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -H 'Idempotency-Key: <key>' \
  -d '{
    "workflow_id": 4,
    "from_status_id": 11,
    "to_status_id": 12,
    "name": "Start progress"
  }'
```