# Guides

Use the guides when you already know the flow you want to integrate and need operational detail, security rules, or implementation decisions.

## Recommended order

| Step | Read this when you need to | Guide |
|  --- | --- | --- |
| **1** | Authenticate requests and understand `DigitalSignature` | [Authentication](/guides/authentication) |
| **2** | Receive asynchronous events safely and idempotently | [Webhooks](/guides/webhooks) |
| **3** | Map failures to retries, alerts, and operator actions | [Error Handling](/guides/error-handling) |


## Pick the right guide fast

| If you are trying to... | Start here |
|  --- | --- |
| Send your first authenticated request | [Authentication](/guides/authentication) |
| Validate webhook delivery before production | [Webhooks](/guides/webhooks) |
| Handle rejected requests or business-rule failures | [Error Handling](/guides/error-handling) |


## API Overview

| Domain | Description |
|  --- | --- |
| **Cash-In** | Generate PIX QR Codes and OpenFinance payment intents. Receive confirmation webhooks when payments land. |
| **Cash-Out** | Send PIX payments to any Brazilian bank account or PIX key. |
| **Account** | View consolidated wallet balances across all banking partners and manage transactional vs. proprietary account rebalance. |
| **Webhooks** | Asynchronous events sent by ConnectPSP when transactions evolve. |


## Key Concepts

### Asynchronous Settlement

Cash-Out requests return `202 Accepted` immediately. Final settlement happens asynchronously through the PIX network (SPI/BACEN), so webhook handling is part of the happy path, not an optional extra.

### Dual Account Architecture

ConnectPSP manages two accounts per banking partner:

- **Transactional** — mirrors your users' total exposure (wallets + in-flight operations)
- **Proprietary** — your operational capital/buffer


Use `POST /account/rebalance` to keep transactional funds aligned with actual user exposure.

### End-to-End IDs (E2E)

Every PIX transaction settled by BACEN receives a unique E2E ID:

- Starts with **`E`** → original payment settled
- Starts with **`D`** → devolution/refund of a previous payment


## Continue the journey

- Start from [Initial Setup](/tutorials/initial-setup) if you are still preparing the integration baseline.
- Use the [Quickstart](/tutorials) section when you want a guided first transaction.
- Open the [API Reference](/apis) when you need exact request and response contracts.