---
title: "Returns a list of required and optional inputs"
method: GET
path: "/parameters"
tags: ["Evaluations"]
---

# Returns a list of required and optional inputs

`GET /parameters`

Given a workflow specified by the header, the API returns a list of required and optional inputs for running an evaluation through the designated workflow. Alloy's API is dynamic, and thus the input parameters vary depending on which services are run and how the workflow is configured. Hitting the `GET /parameters` endpoint will show exactly what your initial `POST /evaluations` request to the Alloy API should look like. All attributes will either be always required, conditionally required, or optional. For instance, in the example here, you either have to pass `document_ssn` OR both `document_license` and `document_license_state`. Note that this response body is just an example, and the exact parameters of your workflow version will vary.

## Headers

- `Authorization` string — Basic authorization header per the OAuth Client Authorization Header standard. The format is `Basic <auth_string>`, where `<auth_string>` is the base64 encoding of the string `token:secret` (check [Authentication Guide](https://developer.alloy.com/public/docs/authentication-guide) for details).
- `alloy-workflow-token` string — If you have migrated to the new API Key Settings page and are using account-level API keys for authentication, this header is required to specify which workflow to use for the evaluation. If you have not migrated yet, this header is optional, as the workflow will be determined by the Authorization header using workflow_token.

## Response `200`

OK

- object
  - `required` object[] — The required fields for this workflow
    - `key` string
    - `type` string
    - `description` string
    - `regex` string
    - `properties` object
  - `optional` object[] — The optional fields for this workflow
    - `key` string
    - `type` string
    - `description` string
    - `regex` string
    - `properties` object
  - `or` object[] — Fields that may be required for this workflow
    - `required` object[]
      - `key` string
      - `type` string
      - `description` string
      - `regex` string
      - `properties` object

---

[API](https://skmtc.dev/alloy/apis/alloy-api.md) · [All operations](https://skmtc.dev/alloy/apis/alloy-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/alloy/alloy-api/revisions/405799de4d2a/schema)