---
title: "POST /cohort-cache/lookup"
method: POST
path: "/cohort-cache/lookup"
---

# POST /cohort-cache/lookup

`POST /cohort-cache/lookup`

## Request

- Base URL: `/analytics-svc/api/services/` (relative, and the document was published on a file host, not at the API’s origin)
- URL: `/analytics-svc/api/services/cohort-cache/lookup`
- Auth: none declared

Looks up cached per-bookmark materialized cohorts for a dataset. A bookmark id returned under entries is a cache hit, including when its materializedCohort is null; only ids with no cached row are returned under missing. Fails if the dataset's PA config cannot be resolved server side, since the cache key cannot then be built.

## Request body

- object
  - `datasetId` string, required: Id of dataset
  - `bookmarkIds` string[], required: Bookmark ids to look up

## Response `200`

Success

- object
  - `entries` object, required: Cached value keyed by bookmark id. A present key is a hit, even when materializedCohort is null.
  - `missing` string[], required: Bookmark ids with no cached row at all
  - `stale` boolean, required: True when at least one returned entry is past its TTL. Such entries are still hits; the caller can serve them and refresh in the background.

## Other responses

- `default`: Error

## Changes

- **2026-09-22** `38d466ba2495`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/ohdsi/apis/health-for-clinical-research/changes/cohort-cache/lookup/post.md)

---

[API](https://skmtc.dev/ohdsi/apis/health-for-clinical-research.md) - [All operations](https://skmtc.dev/ohdsi/apis/health-for-clinical-research/llms.txt) - [OpenAPI document](https://skmtc.dev/ohdsi/apis/health-for-clinical-research/revisions/5655f01517bc?raw)