---
title: "Get subject by external ID"
method: GET
path: "/v1/subjects/external/{externalId}"
tags: ["Subjects"]
---

# Get subject by external ID

`GET /v1/subjects/external/{externalId}`

## Request

- Base URL: `https://idaas.yourflexpay.com/api`
- URL: `https://idaas.yourflexpay.com/api/v1/subjects/external/{externalId}`
- Auth: HTTP bearer
- TypeScript: <https://skmtc.dev/reflexpay/apis/idaas-identity-as-a-service-api/docs/v1/subjects/external/:externalId/get.ts> (a function with typed inputs; its response is checked against the schema)

Looks up a subject by the external identifier in the authenticated application's namespace.

## Path parameters

- `externalId` string, required

## Response `200`

Subject returned

- ApiResponseSubjectResponse
  - `success` boolean
  - `message` string
  - `errorCode` string
  - `data` SubjectResponse
    - `id` string, uuid
    - `applicationId` string, uuid
    - `applicationName` string
    - `externalId` string
    - `displayName` string
    - `email` string
    - `imageUrl` string
    - `metadata` object
    - `createdAt` string, date-time
  - `errors` string[]
  - `timestamp` string, date-time

## Other responses

- `401`: Missing or invalid bearer token
- `404`: Subject not found

## Changes

- **2026-04-17** `db1f954badfb`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/reflexpay/apis/idaas-identity-as-a-service-api/changes/v1/subjects/external/:externalId/get.md)

---

[API](https://skmtc.dev/reflexpay/apis/idaas-identity-as-a-service-api.md) - [All operations](https://skmtc.dev/reflexpay/apis/idaas-identity-as-a-service-api/llms.txt) - [OpenAPI document](https://skmtc.dev/reflexpay/apis/idaas-identity-as-a-service-api/revisions/db1f954badfb?raw)