> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt > Use this file to discover all available pages before exploring further. # What is Pix? > What Pix is and how Brazil's instant payment system works: 24/7 settlement, Pix keys, QR Codes, SPI, DICT, and Direct or Indirect participant models. It enables instant transfers between individuals, businesses, and financial institutions. Pix operates **24/7**, including weekends and holidays. Transactions typically settle in **under 10 seconds**. Pix is low-cost, accessible, and secure across the financial system. # How Pix works *** Pix supports multiple initiation methods: * **Pix Keys:** CPF/CNPJ, phone number, email address, or EVP (random key) * **QR Codes:** Static (reusable) and dynamic (single-use, metadata-rich) * **Manual entry:** Full banking details (bank, agency, account) After confirmation, BACEN’s infrastructure settles the transaction between the institutions, and the receiving institution credits the recipient instantly. # Why Pix matters *** Pix combines speed, accessibility, and regulatory-grade security: * **Instant settlement**: Routed and cleared in seconds * **Always available**: 24/7 operation * **Low cost** or free for individuals * **Secure and auditable**: Every transaction has an E2E ID * **User-friendly**: Human-readable identifiers reduce friction and errors Pix is Brazil’s most widely adopted payment rail. People use it for everyday transfers, merchant payments, and service flows. # Pix modalities *** Pix supports several operational flows defined by BACEN: | Type | Description | | ------------------ | ------------------------------------------------------------ | | **Common Pix** | Standard transfer via key or full account details | | **Pix QR Code** | Static or dynamic EMV-based payment initiation | | **Pix Saque** | Cash withdrawal at authorized merchants | | **Pix Troco** | Payment + cash withdrawal in a single operation | | **Pix Cobrança** | Pix with due dates, penalties, discounts, and reconciliation | | **Pix Agendado** | Scheduled Pix | | **Pix Automático** | Recurring payments | These modalities cover both consumer and business use cases. # Pix infrastructure: SPI and DICT *** Pix relies on two core services operated by BACEN: ## SPI (Instant Payment System) *** The SPI is Pix’s settlement engine. It handles: * Transaction routing between institutions * Real-time clearing * Final, irrevocable settlement Institutions connect to SPI through the **SPI Gateway**, which requires strong cryptography, mTLS, and regulated network connectivity. ## DICT (Directory of Transactional Account Identifiers) *** DICT is the nationwide registry that stores **Pix keys**. It ensures: * Key uniqueness * Lookup of recipient information * Portability between institutions * Ownership validation * Fraud and dispute checks (linked to MED and infractions) Every Pix operation also includes a **unique End-to-End ID (E2E)** for reconciliation and dispute resolution across all participants. # Participants in the Pix ecosystem *** BACEN defines participation models based on how institutions connect to its infrastructure: ### Direct Participants Institutions that connect directly to SPI and DICT. They manage: * Their own Pix messaging and connectivity * Real-time liquidity * Full regulatory, operational, and security compliance This model provides maximum autonomy and control but requires significant infrastructure and governance maturity. ### Indirect Participants Institutions that access Pix through a direct participant (the “sponsor”). The sponsor handles: * Connectivity * Clearing * Settlement * Compliance with BACEN protocols This reduces operational complexity and speeds up time-to-market. ### A practical way to understand it | Scenario | Direct participation | Indirect participation | | ------------------ | -------------------------------------------------- | -------------------------------------------- | | **Transportation** | Owning an airplane and being a licensed pilot | Flying using a commercial airline | | **Food service** | Opening your own restaurant with all legal permits | Operating inside a licensed kitchen | | **Real estate** | Building an entire building | Renting an apartment in a completed building | In all cases, the goal is the same, but the responsibility and complexity shift. End users see no difference between the two models. ### PSTI (Information Technology Service Provider) A PSTI is a BACEN-regulated provider authorized to operate the infrastructure required for financial institutions to connect to the RSFN (National Financial System Network). Using a PSTI allows institutions to: * Connect to BACEN networks without building full infrastructure * Rely on certified, secure, and compliant systems * Maintain control of their ledger and business logic PSTIs ensure regulated communication, data protection, and high availability for Pix participation. # Requirements for participation *** To offer Pix, institutions must follow BACEN’s operational and security standards, which typically include: * mTLS authentication and ICP-Brasil certificates * Regulated connection to the RSFN (directly or via PSTI) * 24/7 availability and redundancy * Real-time monitoring and SLA adherence * Fraud prevention and dispute handling (MED) * Compliance with DICT and SPI message formats * Timely reporting, logging, and auditability * Following nightly limit rules and configurable customer limits These requirements ensure consistent, regulated behavior across the entire ecosystem. **Regulatory reference** For Pix rules, deadlines, and official requirements, always refer to the [official documentation](https://www.bcb.gov.br/estabilidadefinanceira/pix-normas) published by the **Central Bank of Brazil (BACEN)**. This page is a practical overview only. BACEN’s materials are the authoritative source for Pix regulations. They contain the most complete and current specifications. # Pix in the Lerian platform *** Lerian reaches Pix in two ways, and both settle through Midaz. **Lerian SPI** is Lerian's own messaging with BACEN's instant payment system. It connects your institution directly, with no connectivity partner in the path, and it covers the full SPI messaging contract, not only the Pix flows on this page. For the provider-connected path, Lerian provides **Pix Lerian**, a unified interface for operating Pix through stable application contracts. Pix Lerian covers keys and claims, transfers and refunds, collections, and BR Codes. The connectivity provider is configured behind the public contract, so the client integration remains stable. Key characteristics: * **One interface, different connectivity providers**: the client application uses the same public contract regardless of the configured provider * **All participation models**: the interface supports institutions participating directly or indirectly * **Native ecosystem integration**: works with Midaz as the ledger and Access Manager for authentication and authorization Understand the interface, its domains, and the recommended integration journey. Explore the core Pix domains: DICT, Transactions, QR Codes, and MED. Browse the client-facing operations for keys, claims, payments, refunds, and collections.