---
title: "Set Working Set Pin"
method: POST
path: "/api/mind/v2/perspective/{identity_id}/working-set/pin"
tags: ["mind-v2"]
---

# Set Working Set Pin

`POST /api/mind/v2/perspective/{identity_id}/working-set/pin`

## Request

- Base URL: `https://app.thinqos.com` (the document declares no server; this is the origin it was published from)
- URL: `https://app.thinqos.com/api/mind/v2/perspective/{identity_id}/working-set/pin`
- Auth: none declared

Pin or unpin one working-set item (TOS-1086 4.1).

A pinned item is exempt from the working-set TTL and from the attention
score-ordered cap, which together guarantee it prompt entry next turn
(spec section P2: "pinning a working-set item guarantees prompt entry").
The pin overrides SCORE only; it never overrides the TOS-413 disclosure
filter, so a pinned belief still cannot leak to an audience it is not
disclosed to.

Identity-keyed to match ``get_working_set`` (the surface the Mind UI reads
from). Same ownership gate: the caller must own the Mind.
``WorkingSetService.set_pinned`` raises ``ValueError`` when the item is not
in the working set or the pin cap is exceeded; both surface as 409 (a
broken guarantee must fail loudly, never silently).

## Path parameters

- `identity_id` string, uuid, required

## Headers

- `x-impersonate-identity-id` string, nullable

## Request body

- V2WorkingSetPinRequest: Pin or unpin one working-set item (TOS-1086 4.1).
  - `ref_kind` 'proposition' | 'mind_holding', required
  - `ref_id` string, uuid, required
  - `pinned` boolean, required

## Response `200`

Successful Response

- V2WorkingSetResponse: TTL-pruned working set plus its last-write timestamp.
  - `mind_id` string, uuid, required
  - `updated_at` string, date-time, nullable, required
  - `items` V2WorkingSetEntry[], required
    - `ref_kind` 'entity' | 'proposition' | 'mind_holding', required
    - `ref_id` string, uuid, required
    - `score` number, required
    - `decayed_at` string, date-time, required
    - `pinned` boolean

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/thinqos/apis/thinqos-api.md) · [All operations](https://skmtc.dev/thinqos/apis/thinqos-api/llms.txt) · [OpenAPI document](https://skmtc.dev/thinqos/apis/thinqos-api/revisions/5387b4ded614?raw)