> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tesouro.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Quick start

> Get up and running with the Underwriting API in minutes.

<Steps>
  <Step title="Get your credentials">
    Your client ID and client secret are provided by Tesouro during onboarding. To request access, have your designated team lead submit an [access request](https://d92rm.share.hsforms.com/2rxMT-N-nQ-atFj2t5ODm2w).
  </Step>

  <Step title="Get an access token">
    Exchange your credentials for a short-lived JWT:

    ```bash lines theme={null}
    curl --location 'https://api.sandbox.tesouro.com/openid/connect/token' \
      --header 'Content-Type: application/x-www-form-urlencoded' \
      --data-urlencode 'grant_type=client_credentials' \
      --data-urlencode 'client_id=YOUR_CLIENT_ID' \
      --data-urlencode 'client_secret=YOUR_CLIENT_SECRET'
    ```
  </Step>

  <Step title="Make your first API call">
    Use the token to call the GraphQL endpoint. For example, [create an underwriting application](/underwriting/reference/graphql/operations/create-underwriting-application):

    ```bash lines theme={null}
    curl --request POST \
      --url https://api.sandbox.tesouro.com/graphql \
      --header 'Content-Type: application/json' \
      --header 'Authorization: Bearer YOUR_ACCESS_TOKEN' \
      --data '{
      "query": "mutation CreateApp($input: UnderwritingApplicationCreateInput!) { createUnderwritingApplication(input: $input) { underwritingApplication { id status } errors { __typename } } }",
      "variables": {
        "input": {
          "processingActivity": {
            "currency": "USD",
            "averageMonthlySalesAmount": 50000,
            "averageTicketAmount": 120,
            "cardPresentMix": 0.6,
            "cardNotPresentMix": 0.4
          }
        }
      }
    }'
    ```
  </Step>
</Steps>

## Next steps

* Learn about [authentication](/underwriting/guides/authentication/overview) concepts and available methods
* Understand the [underwriting application](/underwriting/guides/applications/index) lifecycle
* Explore the [API concepts](/underwriting/api/concepts/environments) for environments, rate limiting, and pagination