# Documentation

> Documentation files for Large Language Models

## Documentation

- [Webhooks](/webhooks.md): Receive and process final call results.
- [SDKs](/sdks.md): Install SDK 1.0 for single-target Calls and published Goal Runs.
- [Legacy API retirement](/retirement.md): Legacy Calls retirement deadline and migration guidance.
- [Regions & languages](/regions.md): Supported destinations, languages, and line regions.
- [Quickstart](/quickstart.md): Make a phone call and read its structured result.
- [Migration guide](/migration.md): Update call inputs, result handling, webhooks, and SDKs without duplicating calls.
- [Legacy Webhooks](/legacy-webhooks.md): Receive terminal webhook events and process them safely.
- [Legacy SDKs](/legacy-sdks.md): Official and community SDKs.
- [Legacy Quickstart](/legacy-quickstart.md): Create one call and read the structured result.
- [Legacy Calls](/legacy-calls.md): Understand the call creation contract and event flow.
- [Goal Runs](/goal-runs.md): Start outbound calls from a published Goal with one phone number and schema-validated variables.
- [Errors](/errors.md): Handle stable API errors and recovery paths.
- [What's New](/changelog.md): Track CALL-E Developer API and SDK product updates.
- [Calls](/calls.md): Single-target calls, immutable requests, result readiness, and execution boundaries.
- [Billing](/billing.md): CALL-E pricing, billing periods, and call cost examples.
- [Authentication](/authentication.md): Use API keys safely from trusted server environments.

## API Reference

- [API Reference](/api-reference): Browse the read-only CALL-E Developer API reference.
- [OpenAPI Specification](/openapi/calle.openapi.yaml): Read the authoritative OpenAPI 3.1 contract for tools and code generation.