---
title: "Check whether a platform subdomain can be claimed before calling set_app_subdomain"
method: POST
path: "/api/mcp/tools/check_subdomain_available"
tags: ["tools"]
---

# Check whether a platform subdomain can be claimed before calling set_app_subdomain

`POST /api/mcp/tools/check_subdomain_available`

## Request

- Base URL: `https://finestructure.ai`
- URL: `https://finestructure.ai/api/mcp/tools/check_subdomain_available`
- Auth: HTTP bearer

Check whether a platform subdomain can be claimed before calling set_app_subdomain. Returns available plus a status of available, invalid, reserved, taken, current, or empty, with the exact reason. Pass app_id (an app you own) to have that app's own current subdomain reported as 'current' instead of 'taken'.

## Request body

- object
  - `subdomain` string, required: Subdomain label to check
  - `app_id` string: Optional ID of an app you own. When supplied, this app's own subdomain reports as 'current' instead of 'taken'.

## Response `200`

Tool executed successfully

- ToolResult
  - `ok` boolean, required
  - `tool` string, required
  - `result` object, required

## Other responses

- `400`: Invalid arguments for this tool
- `401`: Missing or invalid bearer token
- `402`: Not enough credits on the account
- `403`: Token scope does not permit this tool
- `404`: Unknown tool name
- `429`: Rate limit exceeded, retry after the indicated delay
- `500`: Internal error while executing the tool

---

[API](https://skmtc.dev/finestructure/apis/fine-structure-api.md) · [All operations](https://skmtc.dev/finestructure/apis/fine-structure-api/llms.txt) · [OpenAPI document](https://skmtc.dev/finestructure/apis/fine-structure-api/revisions/02c50ed5fd70?raw)