---
title: "Gap Fill Epw"
method: POST
path: "/api/tools/gap-fill"
tags: ["Tools (analyse and convert EPW files)"]
---

# Gap Fill Epw

`POST /api/tools/gap-fill`

## Request

- Base URL: `https://epw.tools`
- URL: `https://epw.tools/api/tools/gap-fill`
- Auth: none declared

Repair an uploaded EPW: identify missing hours / suspect runs from the QC
report and rebuild the affected columns from reanalysis + nearest-station
observations at the EPW's own (lat, lon, year).

Internally this is a wrapper around the same MERRA-2 + Meteostat pipeline
used by /api/generate/individual, run only for the gaps. The user-facing
label uses "MOSMIX" because that's the brand the gap-fill workflow is
associated with on the site, even though MOSMIX itself is forecast-only.

## Headers

- `X-API-Key` string, nullable

## Response `200`

Successful Response

- unknown

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/epw/apis/epw-tools-api.md) · [All operations](https://skmtc.dev/epw/apis/epw-tools-api/llms.txt) · [OpenAPI document](https://skmtc.dev/epw/apis/epw-tools-api/revisions/e6b60fc7a6d7?raw)