---
title: "Record the return address of a sign-in"
method: POST
path: "/v1/auth/sign-in/start/{appId}"
tags: ["auth"]
---

# Record the return address of a sign-in

`POST /v1/auth/sign-in/start/{appId}`

## Request

- Base URL: `https://api.thebridge.dev` (the document declares no server; this is the origin it was published from)
- URL: `https://api.thebridge.dev/v1/auth/sign-in/start/{appId}`
- Auth: none declared. Required headers: `origin`

Checks the address against the app's registered callback addresses and remembers it server-side for this browser.

## Path parameters

- `appId` string, required

## Headers

- `origin` string, required

## Response `204`

Recorded

## Other responses

- `400`: The address is not registered on the app

---

[API](https://skmtc.dev/thebridge/apis/bridge-api.md) · [All operations](https://skmtc.dev/thebridge/apis/bridge-api/llms.txt) · [OpenAPI document](https://skmtc.dev/thebridge/apis/bridge-api/revisions/290fffcb3d80?raw)