Allow collection_id to be set on entries via the API (POST/PATCH)

Hi team,

I'm building an automation on top of the Bullet API (api.bullet.to/v1) to auto-generate my daily/weekly tasks and file them under the right goal/list. I hit a hard blocker in the current v1 spec: collection_id is present in the Entry response schema, but it's read-only, it cannot be set on POST /entries (create) or PATCH /entries/{id} (update). Both endpoints accept the request and return 200, but the entry is always created/left with collection_id: null, silently ignoring any value sent.

Concrete example of what's blocked: I want to create a task programmatically and file it directly under a nested list, e.g.:

Work └─ Project9 (sub-collection) 

Request I'd expect to work:

POST /v1/entries Authorization: Bearer <token> Content-Type: application/json { "title": "task 32", "kind": "task", "start": "2026-07-05", "period": "day", "collection_id": "7bb75f1c-e78f-4bc9-9cb6-d0222da58d3b" // "Project9 " } 

Today this succeeds but collection_id comes back null, so the task lands unfiled and I have to manually drag it into "Project9 " in the app afterward — every single time, for every automated task.

Why this matters: The nested-collection structure (goal → sub-goal → task) is one of the most useful features of Bullet for breaking down big goals into actionable items, but right now it's only usable through the UI. Without a writable collection_id, the API can't replicate this core workflow, which makes any serious automation (auto-scheduling, imports, integrations) land everything in an unfiled state.

My wish list:

• Accept collection_id on POST /entries at creation time.

• Accept collection_id on PATCH /entries/{id} to move an existing entry between collections.

• (Nice to have) Return a clear validation error if an invalid/non-existent collection_id is passed, rather than silently dropping it.

I would love to help test this once it's available. Thanks for considering it!