---
title: "Prepare a discoverable passkey assertion"
method: POST
path: "/identity/sign_in/discoverable_passkey_assertions"
tags: ["identity", "customer-session", "customer-session-public"]
---

# Prepare a discoverable passkey assertion

`POST /identity/sign_in/discoverable_passkey_assertions`

## Request

- Base URL: `https://api.stablesea.com` (the document declares no server; this is the origin it was published from)
- URL: `https://api.stablesea.com/identity/sign_in/discoverable_passkey_assertions`
- Auth: none declared
- TypeScript: <https://skmtc.dev/stablesea/apis/stable-sea-backend/docs/identity/sign_in/discoverable_passkey_assertions/post.ts> (a function with typed inputs; its response is checked against the schema)

Begin optional username-free business sign-in. Keep the random browser family_token in memory and use it for confirmation. No account or session cookie is selected here.

## Request body

- IdentityDiscoverablePasskeyInput
  - `family_token` string, required

## Response `200`

OK

- IdentitySignInPasskeyChallenge
  - `ceremony_token` string
  - `webauthn_options` unknown

## Other responses

- `400`: Bad Request
- `404`: Not Found
- `429`: Too Many Requests
- `default`: Error response.

## Changes

- **2026-11-05** `5fe1ed6a544a`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/stablesea/apis/stable-sea-backend/changes/identity/sign_in/discoverable_passkey_assertions/post.md)

---

[API](https://skmtc.dev/stablesea/apis/stable-sea-backend.md) - [All operations](https://skmtc.dev/stablesea/apis/stable-sea-backend/llms.txt) - [OpenAPI document](https://skmtc.dev/stablesea/apis/stable-sea-backend/revisions/610b7b0177c4?raw)