# Frequently Asked Questions

Use this page to quickly find answers and jump into the right guide.

## Authentication

**How do I authenticate with the API?**
See the full guide in [Authentication and Access Tokens](/guides/authentication). It covers client credentials, Authorization Code with PKCE, and the [Anonymous User Flow](/guides/authentication#anonymous-user-flow).

**What base URL should I use?**

- Sandbox: `https://api-developer-sandbox.zocdoc.com/`
- Production: `https://api-developer.zocdoc.com/`


Tokens are environment-specific. Use sandbox credentials and tokens with the sandbox base URL.

## Booking and Availability

Relevant if you are building an application that operates on behalf of patients to let them search for providers, determine live provider availability, book appointments, and manage those appointments.

**Can I use Zocdoc's API to search for providers that accept a specific insurance, like Cigna or Aetna?**
Yes. Zocdoc's Booking and Availability APIs allow developers to build experiences that mimic those on zocdoc.com, including searching for nearby providers that accept a patient's insurance, identifying which providers are accepting new patients and when, and booking with a selected provider.

**Can I use Zocdoc's API simply to search for providers and availability, but still book on zocdoc.com?**
Yes. You can redirect users to complete booking on zocdoc.com after they select a specific timeslot in your application. The timeslot response includes a `booking_url` for this purpose. Note: this is only appropriate for certain use cases and partnership arrangements.

**How do I find availability and book an appointment?**
Follow the end-to-end flow in [Find Availability and Book Appointments](/guides/patient/book-appointments).

**How do I reschedule or cancel an appointment?**

- Reschedule: [Reschedule Appointments](/guides/patient/reschedule-appointments)
- Cancel: [Cancel Appointments](/guides/patient/cancel-appointments)


## Practice Operations

Relevant if you are building an application that operates on behalf of providers/practices.

**How do I update accepted insurance offerings?**
See [Update Insurance Offerings](/guides/insurance/update-insurance).

**How do I create or manage timeslots?**
See [Create Timeslots](/guides/scheduling/create-timeslots) for publishing availability.

**How do I manage appointments?**
See appointment management actions in [Appointment Actions](/guides/scheduling/appointment-actions).

## Testing and Environments

**Is there test data I can use?**
Yes. See [API Endpoint Test Scenarios](/guides/testing-data) for safe, repeatable test cases.

**How do I use the anonymous user flow for public search?**
Use the [Anonymous User Flow](/guides/authentication#anonymous-user-flow) to let users search providers or locations without logging in.

## Webhooks

**How do webhooks work and how do I validate them?**
See [Webhooks](/guides/webhooks) for event types, signatures, retries, and validation steps.

## Troubleshooting

**I’m getting 401/403 errors. What should I check?**

- Token is present and not expired
- Token environment matches the base URL
- Required scopes are granted for the operation


**Where is the full API reference?**
Open the [API Documentation](/apis) for endpoints, schemas, and examples.

If you don’t see your question here, check the related guide above or the changelog for recent updates.