---
title: "Sources Versions"
method: GET
path: "/v3/api/sources/versions"
tags: ["sources"]
---

# Sources Versions

`GET /v3/api/sources/versions`

Return the resolved version index for a given monarch-kg release.

Default is the release this API was built against (the `MONARCH_KG_VERSION`
env var, surfaced in `/version`), so the receipt reflects the bytes
actually in the deployed Solr/DuckDB. Falls back to `latest` when the env
var is unset. Specific dates (`2026-05-07`) are also accepted for
retrospective lookups. Pass `dev=true` to read from `monarch-kg-dev/`;
otherwise the deployment-wide default applies (set via the
`MONARCH_KG_USE_DEV` env var, default false).

## Query parameters

- `release` string, nullable
- `dev` boolean, nullable

## Response `200`

Successful Response

- object

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.dev/monarchinitiative/apis/fastapi.md) · [All operations](https://skmtc.dev/monarchinitiative/apis/fastapi/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/monarchinitiative/fastapi/revisions/2ceb106a8c03/schema)