---
title: "Check Domain Limit"
method: POST
path: "/auth/check-domain-limit"
tags: ["domain-limit"]
---

# Check Domain Limit

`POST /auth/check-domain-limit`

Check whether a domain is allowed to sign up.

Checks in order:
1. domain_exclusions — if matched, return banned
2. domain_inclusions — if matched, return allowed (skip count)
3. Count existing users — enforce SIGNUP_DOMAIN_LIMIT

## Request body

- DomainLimitRequest — Request body for checking domain signup limits.
  - `domain` string, required

## Response `200`

Successful Response

- DomainLimitResponse — Response describing whether another signup is allowed for a domain.
  - `allowed` boolean, required
  - `banned` boolean

## Other responses

- `422` — Validation Error

## Changes

- **2026-09-24** `1cffaad2a921` — 1 warning, 1 info
  - removed the optional property `detail` from the response with the `422` status
  - added the required property `error` to the response with the `422` status

[Change history](https://skmtc.dev/pioneer/apis/brain-api/changes/auth/check-domain-limit/post.md)

---

[API](https://skmtc.dev/pioneer/apis/brain-api.md) · [All operations](https://skmtc.dev/pioneer/apis/brain-api/llms.txt) · [OpenAPI document](https://skmtc.dev/pioneer/apis/brain-api/revisions/1cffaad2a921?raw)