Model/backlog/tasks/task-1 - Add-POST-bulk-uploads-trigger-splitter-FastAPI-route.md

id	title	status	assignee	created_date	updated_date	labels	dependencies	priority	ordinal
TASK-1	Add POST /bulk-uploads/trigger-splitter FastAPI route	Done		2026-04-20	2026-04-20 12:31	backend bulk-upload api		high	2000

Description

Expose an HTTP route that the frontend can call instead of sending SQS directly. Route:

POST /bulk-uploads/trigger-splitter

Body: {task_id, sub_task_id, s3_uri} — task+subtask already created by frontend /api/tasks call before this is invoked.

Behaviour: validate inputs, then publish an SQS message to the postcode_splitter queue (see backend/postcode_splitter/main.py for expected message shape: {task_id, sub_task_id, s3_uri}). Use existing SubTaskInterface / TasksInterface patterns from backend/app/tasks/router.py.

Place under backend/app/ next to tasks/router.py — likely backend/app/bulk_uploads/router.py.

Acceptance Criteria

• #1 Route returns 202 with {task_id, sub_task_id}
• #2 SQS message enqueued with correct shape for postcode_splitter Lambda
• #3 Auth via existing validate_token dependency
• #4 Queue URL from config, not hardcoded
• #5 Unit test with mocked boto3 sqs client