---
title: "Get payer details (FHIR Aggregator or FhirPayer)"
method: GET
path: "/v1/internal/payer"
tags: ["Internal"]
---

# Get payer details (FHIR Aggregator or FhirPayer)

`GET /v1/internal/payer`

Validates ClientId and XApiKey against FHIR.Clients. The client must have ClientType FhirAggregator or FhirPayer. FhirProvider clients receive **400** with "One of ProviderTaxId, VendorId, or GlobalProviderId is required" (use GET /v1/internal/provider). Returns the first active ClientMappings row (lowest Id): PayerId and Validation.PayerID are AgencyId (payer/agency in HHA), and Environment is derived from the mapping Env. BaseUrl is always null.

## Query parameters

- `ClientId` string, required — Client ID (mandatory)
- `XApiKey` string, required — API key (mandatory)

## Response `200`

Successful Response

- PayerDetailsResponse — Response for GET /internal/payer: aggregator client, first active mapping as payer context.
  - `Message` string
  - `ClientId` string
  - `XApiKey` string
  - `BaseUrl` string, nullable
  - `PayerId` integer, nullable
  - `UserId` integer
  - `UserName` string
  - `Environment` string
  - `Validation` object

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.net/hhaexchange/apis/fastapi.md) · [All operations](https://skmtc.net/hhaexchange/apis/fastapi/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/hhaexchange/fastapi/revisions/17ca04f67931/schema)