---
title: "Check whether a capsule alias is free in a Type before you create the capsule"
method: GET
path: "/api/preview/capsules/alias-availability"
tags: ["capsule"]
---

# Check whether a capsule alias is free in a Type before you create the capsule

`GET /api/preview/capsules/alias-availability`

## Request

- Base URL: `https://symbol.chat` (the document declares no server; this is the origin it was published from)
- URL: `https://symbol.chat/api/preview/capsules/alias-availability`
- Auth: one of:
  - HTTP bearer
  - API key in cookie `__Secure-next-auth.session-token`
  - OAuth 2
    - Authorization code: `https://mcp.symbol.chat/authorize`
    - Token URL: `https://mcp.symbol.chat/token`

## Query parameters

- `type_id` string, required: The Type the capsule is created in.
- `alias` string, required: The alias to check, trimmed by the server. A malformed alias is answered with `available: false` and its format `reason`.

## Response `200`

Successful response

- object: Whether a capsule alias is free in a Type, and if not, why.
  - `available` boolean, required
  - `message` string: A sentence to show beside the alias.
  - `reason` string: Why the alias is unavailable: a format reason from the alias grammar, or `taken_live`, `taken_tombstone` or `taken_deleted`.
  - `reclaimable` boolean: True when the alias belonged to a deleted capsule and a create with `reclaim_alias: true` reuses it.

## Changes

- **2026-11-08** `fd7b0a7085e4`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/symbol-chat/apis/symbol-api/changes/api/preview/capsules/alias-availability/get.md)

---

[API](https://skmtc.dev/symbol-chat/apis/symbol-api.md) - [All operations](https://skmtc.dev/symbol-chat/apis/symbol-api/llms.txt) - [OpenAPI document](https://skmtc.dev/symbol-chat/apis/symbol-api/revisions/3ae8310b31e1?raw)