---
title: "Complete a verified sign-in update"
method: POST
path: "/identity/factor_migrations/completions"
tags: ["identity", "customer-session", "customer-session-public"]
---

# Complete a verified sign-in update

`POST /identity/factor_migrations/completions`

## 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/factor_migrations/completions`
- Auth: none declared. Required headers: `Idempotency-Key`

Requires migration_token, its verified current alternate proof and a stable Idempotency-Key. Completes legitimate interrupted signup through its existing checkpointed workflow where applicable, then atomically retires SMS, preserves other factors, records migration and durable security notices, and returns one ordinary business-selection handoff. Exact retries return that same live unconsumed handoff only within original authority expiry. No cookie is installed here.

## Headers

- `Idempotency-Key` string, required

## Request body

- IdentityMigrationCompletionInput
  - `migration_token` string, required

## Response `200`

OK

- IdentitySignInStep2Output
  - `groups` IdentitySignInStep2GroupOutput[], nullable
    - `business_eligible` boolean
    - `group_id` string
    - `individual` IdentitySignInStep2IndividualOutput
      - `email` string
      - `first_name` string
      - `id` string
      - `last_name` string
      - `status` string
    - `relationship` string
  - `migration_expires_ts` string, date-time, nullable
  - `migration_required` boolean
  - `migration_token` string
  - `session_token` string
  - `success` boolean

## Other responses

- `400`: Bad Request
- `401`: Unauthorized
- `403`: Forbidden
- `404`: Not Found
- `409`: Conflict
- `429`: Too Many Requests
- `503`: Service Unavailable
- `default`: Error response.

## Changes

- **2026-11-04** `fb17fc318db3`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/stablesea/apis/stable-sea-backend/changes/identity/factor_migrations/completions/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/fb17fc318db3?raw)